Factor Xa inhibitors for acute coronary syndromes (Review) Brito V, Ciapponi A, Kwong J This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library 2011, Issue 3 http://www.thecochranelibrary.com Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. TABLE OF CONTENTS HEADER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 PLAIN LANGUAGE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 SUMMARY OF FINDINGS FOR THE MAIN COMPARISON . . . . . . . . . . . . . . . . . . . 2 BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 AUTHORS’ CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 CHARACTERISTICS OF STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 DATA AND ANALYSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Analysis 1.1. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 1 All-cause mortality at 30 days. . . . . 43 Analysis 1.2. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 2 All-cause mortality at 90 to 180 days. . . 44 Analysis 1.3. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 3 Non-fatal AMI or re-infarction at 9 days. 45 Analysis 1.4. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 4 Non-fatal AMI or re-infarction at 30 days. 46 Analysis 1.5. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 5 Combined endpoint of all-cause mortality, nonfatal AMI or re-infarction at 9 days. . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Analysis 1.6. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 6 Major bleeding at 9 days. . . . . . . 48 Analysis 1.7. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 7 Major bleeding at 30 days. . . . . . 49 Analysis 1.8. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 8 Minor bleeding at 30 days. . . . . . 50 Analysis 2.1. Comparison 2 Low dose fondaparinux vs. anticoagulants, Outcome 1 All-cause mortality at 30 days. . 51 Analysis 2.2. Comparison 2 Low dose fondaparinux vs. anticoagulants, Outcome 2 Non-fatal AMI or re-infarction at 30 days. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Analysis 2.3. Comparison 2 Low dose fondaparinux vs. anticoagulants, Outcome 3 Major bleeding at 9 days. . . . 53 Analysis 3.1. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 1 All-cause mortality at 30 days. . . 54 Analysis 3.2. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 2 Non-fatal AMI or re-infarction at 30 days. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Analysis 3.3. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 3 Major bleeding at 9 days. . . . . 56 Analysis 3.4. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 4 Catheter thrombosis. . . . . . 57 Analysis 4.1. Comparison 4 Sensitivity analyses, Outcome 1 All-cause mortality at 30 days. . . . . . . . . . 58 Analysis 4.2. Comparison 4 Sensitivity analyses, Outcome 2 Major bleeding at 9 days. . . . . . . . . . . . 59 ADDITIONAL TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 WHAT’S NEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 CONTRIBUTIONS OF AUTHORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 DECLARATIONS OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 SOURCES OF SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 DIFFERENCES BETWEEN PROTOCOL AND REVIEW . . . . . . . . . . . . . . . . . . . . . 63 NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. i INDEX TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 63 ii [Intervention Review] Factor Xa inhibitors for acute coronary syndromes Viviana Brito1 , Agustín Ciapponi2 , Joey Kwong3 1 Coronary Care Unit, Hospital de Clinicas, Universidad de Buenos Aires, Ciudad Autonoma Buenos Aires, Argentina. 2 Argentine Cochrane Centre IECS - Family and Community Medicine Service, Institute for Clinical Effectiveness and Health Policy - Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. 3 Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK Contact address: Viviana Brito, Coronary Care Unit, Hospital de Clinicas, Universidad de Buenos Aires, Avenida Cordoba 2351 Piso Sala 1, Ciudad Autonoma Buenos Aires, Capital Federal, Argentina. vbrito@intramed.net. Editorial group: Cochrane Heart Group. Publication status and date: Edited (no change to conclusions), comment added to review, published in Issue 3, 2011. Review content assessed as up-to-date: 30 April 2009. Citation: Brito V, Ciapponi A, Kwong J. Factor Xa inhibitors for acute coronary syndromes. Cochrane Database of Systematic Reviews 2011, Issue 1. Art. No.: CD007038. DOI: 10.1002/14651858.CD007038.pub2. Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. ABSTRACT Background The activation of coagulation mechanisms plays a central role in the pathogenesis of acute coronary syndromes (ACS). Administration of unfractionated heparin (UFH) and low molecular weight heparins (LMWH), agents preventing the progression of thrombus formation, is a crucial therapeutic strategy. However, some limitations related to their use have recently stimulated the development of new synthetic agents. Objectives To evaluate the clinical efficacy and safety of factor Xa inhibitors for treatment of ACS compared to UFH or LMWH. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) of the Cochrane Library (Issue 1, 2008), PubMed, EMBASE and LILACS as well as the publications from International Congresses and the reference lists of the selected studies in December 2008. Selection criteria We used randomized controlled trials (RCTs) comparing factor Xa inhibitors to UFH or LMWH during the course of ACS. Outcome measures included all-cause mortality, myocardial infarction, re-infarction, ischemia recurrence, and adverse events. Data collection and analysis The selection, quality assessment and data extraction of the included trials were done independently by two authors and disagreements were resolved by consensus. Data were analysed by the use of risk ratio (RR) with 95% confidence interval (CI), and the numbers needed to treat (NNT) were reported as needed. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 1 Main results A total of four RCTs involving 27,976 subjects were included. Fondaparinux was the only factor Xa inhibitor identified in our included RCTs. Fondaparinux appeared to be related to a lower risk in all-cause mortality at 90 to 180 days (RR 0.89; 95% CI 0.81 to 0.97), especially in the group where enoxaparin (a LMWH) was the control drug. Fondaparinux was also associated with a lower risk in major and minor bleeding at 30 days compared to enoxaparin (RR 0.63, 95% CI 0.55 to 0.73; RR 0.34, 95% CI 0.28 to 0.43, respectively), but not when compared to UFHs (RR 1.41; 95% CI 0.49 to 4.10; RR 0.70, 95% CI 0.14 to 3.39 respectively). Authors’ conclusions The therapeutic efficacy of factor Xa inhibitors in ACS seemed to be related to a reduced risk in all-cause mortality at 90 to 180 days, with a better safety profile than enoxaparin in terms of reduce incidence of major and minor bleeding. PLAIN LANGUAGE SUMMARY Factor Xa inhibitors for acute coronary syndromes The use of unfractionated heparin and low molecular weight heparins greatly reduces the risk of mortality and morbidity in acute coronary syndromes. However, their use has been associated with a risk of adverse events such as major bleeding, which has prompted researchers to seek safer alternative anticoagulants such as the synthetic inhibitors of the Xa factor - a crucial enzyme in the coagulation cascade. We systematically reviewed efficacy and safety of factor Xa inhibitors in treating acute coronary syndromes when compared to unfractionated heparins or low molecular weight heparins. A total of four trials involving 27,976 subjects was included. Xa inhibitors reduced all-cause mortality at 30 days, with the effect becoming more significant at 180 days. However, no significant differences were observed in the incidence of myocardial infarction or reinfarction at 30 days. Factor Xa inhibitors were found to be safer than enoxaparin, a low molecular weight heparin, due to reduced incidences of major and minor bleeding at 30 patients in patients receiving conservative treatment. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 2 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 3 Factor Xa inhibitors Control All causes of mortality at Study population 30 days - Enoxaparin Follow-up: 30 days 40 per 1000 Medium risk population All causes of mortality at Study population 30 days - UFH 67 per 1000 Follow-up: 30 days 24 per 1000 Medium risk population 39 per 1000 (33 to 47) 66 per 1000 (55 to 79) 22 per 1000 (19 to 24) 38 per 1000 (34 to 42) Corresponding risk Assumed risk Illustrative comparative risks* (95% CI) All causes of mortality at Study population 30 days 42 per 1000 Follow-up: 30 days Outcomes Patient or population: Anticoagulants in ACS Settings: Intervention: Factor Xa inhibitors RR 0.85 (0.73 to 0.98) RR 0.98 (0.82 to 1.18) RR 0.9 (0.8 to 1.01) Relative effect (95% CI) Factor Xa inhibitors compared to Anticoagulants in ACS for acute coronary syndromes 21216 (2 studies) 6760 (2 studies) 27976 (4 studies) No of Participants (studies) S U M M A R Y O F F I N D I N G S F O R T H E M A I N C O M P A R I S O N [Explanation] ⊕⊕⊕⊕ high ⊕⊕⊕⊕ high ⊕⊕⊕⊕ high Quality of the evidence (GRADE) Comments Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 4 49 per 1000 Medium risk population Major bleeding at 30 Study population days - Enoxaparin 49 per 1000 Follow-up: 30 days 47 per 1000 Medium risk population Major bleeding at 30 Study population days - UFH 47 per 1000 Follow-up: 30 days 48 per 1000 Medium risk population Major bleeding at 30 Study population days 49 per 1000 Follow-up: 30 days 24 per 1000 Medium risk population 35 per 1000 50 per 1000 (49 to 50) 50 per 1000 (49 to 50) 46 per 1000 (43 to 49) 46 per 1000 (43 to 49) 48 per 1000 (47 to 50) 49 per 1000 (48 to 51) 20 per 1000 (18 to 24) 30 per 1000 (26 to 34) RR 1.02 (1.01 to 1.02) RR 0.98 (0.92 to 1.04) RR 1.01 (0.98 to 1.04) 20078 (1 study1 ) 326 (1 study1 ) 20404 (2 studies1 ) ⊕⊕⊕⊕ high ⊕⊕⊕⊕ high2 ⊕⊕⊕⊕ high Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 5 11 per 1000 (9 to 14) 11 per 1000 (9 to 14) 62 per 1000 (18 to 208) 62 per 1000 (18 to 208) 24 per 1000 (5 to 115) 22 per 1000 (4 to 108) RR 0.34 (0.28 to 0.43) RR 1.76 (0.52 to 5.94) RR 0.7 (0.14 to 3.39) 20078 (1 study1 ) 326 (1 study1 ) 20404 (2 studies1 ) ⊕⊕⊕⊕ high ⊕⊕⊕ moderate2 ⊕⊕⊕⊕ high *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio; 32 per 1000 Medium risk population Minor bleeding at 30 Study population days - Enoxaparin 32 per 1000 Follow-up: 30 days 35 per 1000 Medium risk population Minor bleeding at 30 Study population days - UFH 35 per 1000 Follow-up: 30 days 34 per 1000 Medium risk population Minor bleeding at 30 Study population days 32 per 1000 Follow-up: 30 days Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 6 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Even though the control group was on anticoagulant treatment, all of them have had an acute coronary syndrome so the risk was assumed as medium 2 Although the total number of events is less than 300, the narrow 95% confidence interval of the RR is lower than 25% between study drug group and control one 1 GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. BACKGROUND Acute coronary syndromes (ACS) are life-threatening disorders which remain as a common cause of cardiovascular morbidity and mortality, accounting for half of all deaths due to cardiovascular diseases and contributing to high economic burden to global health care systems (ACC/AHA 2009; ACCP 2008; ESC Guideline 2007). ACS include three clinical entities: unstable angina, non ST-elevation myocardial infarction (Non-STEMI) and ST-elevation myocardial infarction (STEMI) (ESC Guideline 2007). The syndromes are the result of vulnerable atherosclerotic plaques with high risk of fissures or erosion, leaving large areas of the subendothelial connective tissue of the plaque exposed, which predisposes to development of a total or partially occlusive thrombus as a consequence of the exposure to the thrombogenic blood stream constituents (ACC/AHA 2007; Davies 2000; Hamm 2000). The appropriate management of ACS requires intensive medical therapy often associated to invasive cardiovascular procedures. Since the patients with the disorder exhibit high levels of markers produced by thrombin generation, the activation of coagulation mechanisms seems to play a central role in the pathogenesis of ACS (ACCP 2008; Bonaca 2009). According to this, the administration of unfractionated heparin (UFH) and low molecular weight heparins (LMWH) in the treatment of unstable angina and NonSTEMI has the objective of inhibiting thrombin generation and/ or preventing the progression of thrombus formation, via their activity in accelerating the activation of the proteolytic enzyme antithrombin, an inhibitor of anticoagulation factors IIa, Ixa, and Xa (ACC/AHA 2007; Hamm 2000). In STEMI, heparins are used as an adjuvant therapy to fibrin-specific thrombolytic agents in order to avoid paradoxical activation of the blood coagulation cascade (ACC/AHA 2009; ESC Guidelines 2008; Goodman 2008). Although UFH and LMWH have shown clinical efficacy and safety, some limitations are associated with their use. The pharmacokinetic profile of UFH is characterized by poor bioavailability at low doses and short half life via the subcutaneous route, which determine its intravenous route necessary. Moreover, after treatment discontinuation, the recurrence of clinical events as a consequence of reactivation of the coagulation process has been described (ACCP 2008). On the other hand, enoxaparin, a LMWH, has a predictable dose-effect relationship so it is effectively administrated subcutaneously without the need to monitor activated partial thromboplastin time (aPTT or APTT), although its intravenous administration is necessary in urgent situations because its maximum plasma levels occur three to five hours after subcutaneous administration (ACCP 2008). It must also be noted that enoxaparin is associated with a lower risk of thrombocytopenia and osteoporosis than UFH, but with a higher frequency of minor bleeding as well as some uncertainty about its use in obese subjects and patients with renal insufficiency, particularly if creatinine clearance is lower than 30 mL/min. Therefore monitoring of its plasma levels may be useful in these special populations to avoid inadequate drug concentrations during treatment (Bassand 2008; Lim 2006; McCaan 2008; Warkentin 2008). To overcome the limitations of these anticoagulants, development of new synthetic agents with better efficacy and safety profiles has been pursued (Bassand 2008; Hirsh 2005). These new agents target the inhibition of anticoagulation by blocking its initiation through preventing thrombin generation or inhibiting thrombin action (ACCP 2008; Barantke 2008). Inhibitors of activated factor X (Xa), such as fondaparinux, exert their antithrombotic activity by selectively binding to the co-factor antithrombin to induce the neutralization of factor Xa (Blick 2008). Neutralization of factor Xa interrupts the blood coagulation cascade and thus inhibits thrombin generation and thrombus development (Hirsh 2005). Xa inhibitors also prevent the interaction of factor Xa with other substrates by binding directly to its active sites (Barantke 2008; Comp 2003). These newer synthetic agents may have numerous potential advantages compared to UFH or LMWH, such as having no requirement to monitor coagulation parameters because there is no binding to plasma proteins, and low drug interactions which allows a predictable dose-effect ratio and an easier administration regimen (Crowther 2004; Eikelboom 2010; Hirsh 2007). The most common adverse effect reported with the use of Xa inhibitors has been major/minor bleeding (major 2.7%, minor 3%) and secondary local bruising, which in clinical trials have been reported doubled in patients weighing less than 50 kg (Brown 2007). The absence of thrombocytopenia with the use of fondaparinux makes it an attractive alternative (Franchini 2005). Nevertheless, the future role of these new anticoagulants and their clinical utility and safety profiles in the treatment of ACS is still a matter of current investigation (Crowther 2004; Eikelboom 2010; Franchini 2005; Hirsh 2007; Linkins 2005; Warkentin 2008). In this review we systematically reviewed the evidence and data available to investigate the impact of Xa inhibitors in the management of unstable angina, Non-STEMI and STEMI. OBJECTIVES To evaluate the efficacy and safety of factor Xa inhibitors in the treatment of ACS. METHODS Criteria for considering studies for this review Types of studies Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 7 Randomised controlled trials (RCTs) in which factor Xa inhibitors have been compared with other anticoagulant strategies, where both the control and study groups have received currently accepted standards of care for ACS ( ACC/AHA 2008; ACC/AHA 2009; ESC Guideline 2007; ESC Guidelines 2008). Quasi-experimental studies and other non-randomised designs were not included. Types of participants Adults (≥ 18 years) admitted for ACS, including unstable angina, STEMI and Non-STEMI. Types of interventions Administration of direct and indirect factor Xa inhibitors at any dose, compared against LMWH or UFH. Types of outcome measures Primary outcome • All-cause mortality at 30 days and 90 - 180 days • Non fatal acute myocardial infarction or re-infarction at 30 days • Recurrent angina at 30 days Secondary outcome • Stroke • Heart failure • Need of revascularization in the following 30 days after discharge • Flow grade of the infarct related vessel according to the Thrombolysis in Myocardial Infarction (TIMI) flow grading system, assessed during the first week as an angiographic efficacy endpoint • Combined endpoint: cardiovascular mortality, non-fatal acute myocardial infarction, recurrent angina • Length of hospitalisation • Readmission to hospital • Quality of life Primary adverse effects endpoints • Major bleeding • Thrombocytopenia development, taking into account immune as well as non-immune mediated forms, defined as a drop of the platelet count to below of 100x109 /L or more than 50% from the patient’s baseline platelet count which resolved after cessation of heparin (Franchini 2005). Secondary adverse effects endpoints • Drop-out due to adverse effects • Minor bleeding • Other adverse events: such as allergic reactions, or withdrawal from intervention Accepted definitions: Myocardial Infarction (AMI): Elevation of cardiac enzyme creatine kinase isoenzyme MB (CK-MB) ≥ two higher than the normal superior limit (NSL), ≥ three after a percutaneous coronary procedure, ≥ five after a coronary artery bypass graft, or complete left brunch block or new Q waves on electrocardiogram with twofold or greater elevation of cardiac enzymes compared to the NSL. Myocardial re-Infarction in patients admitted with a STEMI: recurrent chest pain associated to new ST-segment elevation or elevation of creatine kinase or creatinine kinase-MB levels to up to 50%. Recurrent Ischemia: ST-segment depression of 1 mm at least one minute during the continuous electrocardiographic of 12 hours monitoring (asymptomatic), chest pain combined to ST-segment depression of at least 1mm, or elevation of this segment (symptomatic episodes), or new admission at the hospital due to unstable angina. Urgent Revascularization: recurrence of Ischaemic symptoms evolving to a percutaneous coronary artery intervention or coronary artery bypass graft. Major Bleeding: evident bleeding associated with death, risk of death, surgery or need of a new surgical intervention to control the bleeding; retroperitoneal, intracerebral or in other critical organ; an haemoglobin fall ≥1.2 mmol/L (2 g/L), or requiring blood transfusion with ≥2 units of entire blood or red globular packs, using a modified TIMI or major bleeding definition criteria ( Cannon 2001; Yusuf 2006 OASIS 5; Yusuf 2006 OASIS 6). Minor Bleeding: any bleeding other than major bleeding, minor bleedings on venipuncture area were not considered. †TIMI bleeding definition criteria: 1. Major: Overt clinical bleeding (or documented intracranial or retroperitoneal haemorrhage) associated with a drop in haemoglobin of greater than 5 g/dL (50 g/L) or in hematocrit of greater than 15% (absolute) Note: A patient who experiences an intracranial haemorrhage should be considered to have a major haemorrhage. 2. Minor: Overt clinical bleeding associated with a fall in haemoglobin of 3 to 5 g/dl (50 g/l) or in hematocrit of 9% to 15% (absolute) 3. None: No bleeding event that meets the major or minor definition Note: In calculating the fall in haemoglobin or hematocrit, a transfusion of whole blood or packed red blood cells is counted as 1 g/dL (10 g/L) haemoglobin or 3% absolute in hematocrit. This would be in addition to the actual fall in haemoglobin or hemat- Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 8 ocrit. Stroke: new neurological deficit lasting more than 24 hours. TIMI Flow Grading System: flow in the culprit artery is defined as follows (Cannon 2001): 1. Grade 0 (no perfusion): There is no antegrade flow beyond the point of occlusion 2. Grade 1 (penetration without perfusion): The contrast material passes beyond the area of obstruction but “hangs up” and fails to opacify the entire coronary bed distal to the obstruction for the duration of the cineangiographic filming sequence 3. Grade 2 (partial perfusion): The contrast material passes across the obstruction and opacifies the coronary bed distal to the obstruction. However, the rate of entry of contrast material into the vessel distal to the obstruction or its rate of clearance from the distal bed (or both) is perceptibly slower than its entry into or clearance from comparable areas not perfused by the previously occluded vessel (e.g., the opposite coronary artery or the coronary bed proximal to the obstruction) 4. Grade 3 (complete perfusion): Antegrade flow into the bed distal to the obstruction occurs as promptly as antegrade flow into the bed from the involved bed and is as rapid as clearance from an uninvolved bed in the same vessel or the opposite artery. Search methods for identification of studies Electronic searches We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 1, 2008), PubMed (January 1980 to December 2008), EMBASE (January 1980 to December 2008) and LILACS (January 2000 to December 2008). No language restrictions were applied. The search strategies are detailed in Appendix 1. Citations retrieved by the searches and full-text papers retrieved were examined by two authors independently (AC, VB). The lists of those chosen were compared and disagreements resolved by consensus. Data extraction and management Data from the included studies were extracted by two authors (AC, VB) independently using a pre-prepared data extraction form. The form was piloted on three trial reports to ensure that it was suitable for use. Dsagreements were resolved by consensus. Trialists were contacted for further information and clarification if data were missing. The following information was recorded: 1. Trial design, including method of generation and concealment of allocation sequences, and type of control intervention; report of excluded and loss to follow-up cases; publication type and source, including language of publication, year of publication, method of retrieval of the report; sources of support; setting, including country and level of care and analysis, including whether analysis was done according to the intentionto-treat principle, statistical test and P-values for comparisons within and between groups. 2. Intervention, including dose, route of administration, and duration of treatment, modalities and schedule of assessments of outcome measures. 3. Demographic and clinical variables of the patients such as: age, sex, history of diabetes, arterial hypertension, smoking, hyperlipemias, coronary artery disease, heart failure, and the selection criteria used. 4. Variables related to the outcomes of interest: global and cardiac mortality, new non-fatal myocardial infarction or reinfarction, refractory angina, urgent or elective revascularization needed, quality of life, major or minor bleeding, development of thrombocytopenia, and other adverse events. Searching other resources We handsearched material from the International Congresses of the European Society of Cardiology, American Heart Association and American College of Cardiology (2002 to December 2008). Authors as well as pharmaceutical companies producing relevant drugs were contacted by electronic and/or postal mail for unpublished data or any missing data where necessary. The reference lists of included studies have also been considered as a source of relevant information. Published or unpublished studies were considered for inclusion in the review. Data collection and analysis Selection of studies Assessment of risk of bias in included studies Two authors (AC, VB) independently assessed the risk of bias in included studies using the Cochrane Collaboration’s tool for assessing risk of bias (Higgins 2009). Disagreements were resolved by discussion. The following criteria were considered: Selection bias (randomization method and allocation concealment); Performance bias (blinded of patients and people administering the treatment); Attrition bias (lost to follow-up); Detection bias (blinding of outcome assessors). The risk of bias in each study was graded as follows (Table 1): A - all quality criteria met (low risk of bias); B - one or more criteria partly met (moderate risk of bias); and C - one or more criteria not met (high risk of bias). Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 9 Measures of treatment effect RESULTS For normally distributed outcomes, summary estimates of the treatment effect were calculated using the inverse variance method. Dichotomous data were analysed by the use of risk ratio (RR) with confidence interval (CI) of 95%, while continuous data were analysed by weighted or standardised mean difference according to the available data. Numbers needed to treat for an additional beneficial outcome (NNTB) as well as numbers needed to treat for an additional harmful outcome (NNTH) were estimated. All of the analyses was based on the intention-to-treat data from individual clinical trials. Heterogeneity was classified on statistical and clinical grounds, by two independent reviewers (AC, VB). Description of studies Subgroup analysis and investigation of heterogeneity The following subgroup analyses were performed where possible: • By different drugs; • By doses of the drugs; doses < 5 mg were considered as low and ≥ 5 mg as high; • Patients aged 75 years or older compared to younger patients; • Patients referred to in-hospital percutaneous coronary intervention (PCI); • Patients on treatment with Xa inhibitors receiving drugs other than heparins, which could also affect the platelet aggregation or interfere with the coagulation cascade, potentially increasing the risk of adverse events. Statistical heterogeneity was examined using the I² statistic (a threshold of 50% was used to define significant heterogeneity) and the Chi² statistic (with significance being set at P < 0.10). If there was no statistical or clinical heterogeneity, a fixed-effect model was reported. Otherwise a random-effects model was applied. Both clinical and methodological sources of heterogeneity were explored. Sensitivity analysis Sensitivity analyses were performed to explore the impact of methodological quality on treatment effects. See: Characteristics of included studies; Characteristics of excluded studies; Characteristics of studies awaiting classification. Our search strategy yielded 171 titles after de-duplication. Two additional records were retrieved through handsearching and from the reference lists of pre-selected studies, thus a total of 173 records was screened. After reviewing the titles and abstracts, 15 full-text papers were retrieved. Articles in which the outcomes considered were unrelated to our analyses (Mehta 2007; Cohen 2007; Vuillemenot 1999) or the interventions involved investigative agents (Alexander 2005) were excluded. Further information on these four excluded studies are available in the section Characteristics of excluded studies. A total of four RCTs in 11 papers was included in our review. These four included studies are multi-centre RCTs involving 27,976 subjects in different countries conducted in America and in Europe (Characteristics of included studies). Fondaparinux, an indirect factor Xa inhibitor, was the agent used in all four trials and it was compared against UFH or enoxaparin as controls. The range of age of the participants was 48 to 68 years old. The male gender was represented by nearly 80%, and co-morbidities such as diabetes, arterial hypertension, heart failure or history of previous coronary events were present in a proportion usual for the population taking part of this kind of trials. Two studies have been identified outside of our search period ( Oasis 8; Sabatine 2009). Conscious of their importance and of timing to publish this review, we decided to group these studies as studies awaiting classification. The corresponding data will be extracted and analysed in our next update. Details on these two studies are given in the section Characteristics of studies awaiting classification. The study selection process in the form of a PRISMA flow chart is shown in Figure 1. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 10 Figure 1. Flow chart of selection studies Risk of bias in included studies Allocation An appropriated method of randomization and allocation concealment through a central telephonic or computerized voice system was reported in three of the four trials evaluated. In one trial (Yusuf 2006 OASIS 6) the mechanism of randomization was not described in detail (Figure 2; Figure 3; Summary of findings for the main comparison). According to this, additional information has been requested from the authors about the mechanisms involved in these processes, which we hope to be available for updates of this review. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 11 Figure 2. Methodological quality graph: review authors’ judgements about each methodological quality item presented as percentages across all included studies. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 12 Figure 3. Methodological quality summary: review authors’ judgements about each methodological quality item for each included study. Blinding Four studies were double blind and one was not blinded ( Coussement 2001). Incomplete outcome data One of the studies had only 82% of the information completed during follow-up (Simoons 2004), but the rest of the trials contained information from as much as 99.9% of the recruited par- ticipants. Other potential sources of bias The funnel plots showed asymmetry in all-cause mortality, AMI/ re-AMI, and major/minor bleeding at 30 days. This reflects fundamental methodological heterogeneity such as different clinical conditions and treatment strategies used, but we did not think the assymetry was attributed to publication bias (Figure 4; Figure 5; Figure 6; Figure 7; Figure 8). Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 13 Figure 4. Funnel plot of comparison: 1 xa factor inhibitors vs Anticoagulants in ACS, outcome: 1.1 All causes of mortality at 30 days. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 14 Figure 5. Funnel plot of comparison: 1 xa factor inhibitors vs Anticoagulants in ACS, outcome: 1.2 All causes of mortality at 90 to 180 days. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 15 Figure 6. Funnel plot of comparison: 1 Xa factor inhibitors vs Anticoagulants in ACS, outcome: 1.4 AMI or Re- AMI at 30 days. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 16 Figure 7. Funnel plot of comparison: 1 xa factor inhibitors vs Anticoagulants in ACS, outcome: 1.7 Major bleeding at 30 days. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 17 Figure 8. Funnel plot of comparison: 1 xa factor inhibitors vs Anticoagulants in ACS, outcome: 1.8 Minor bleeding at 30 days. All the included studies were either funded by for-profit organizations or the authors received research support or consultant fees from the pharmaceutical companies that are associated with the study drug. However, the studies were conducted and the data analysed in an independent fashion by steering or safety committees and/or the research institutes in charge. There was no clear rationale to suggest biased reporting based on this link between the authors and the companies which funded the research. Effects of interventions See: Summary of findings for the main comparison Factor Xa inhibitors compared to Anticoagulants in ACS for acute coronary syndromes Outcomes evaluating clinical efficacy and safety of fondaparinux were assessed as below. We also analysed the clinical effectiveness and safety of fondaparinux at low dose. Sensitivity analyses exploring the effect measures related to fondaparinux were performed where appropriate. Summary of our findings are given in Summary of findings for the main comparison. Primary clinical outcomes All-cause mortality at 30 and 90 to 180 days All four trials (two trials comparing against enoxaparin involving 6,760 patients; two comparing against UFH involving 21,216) reported all-cause mortality as an outcome measure (Coussement 2001; Simoons 2004; Yusuf 2006 OASIS 5; Yusuf 2006 OASIS 6). A lower mortality rate was observed with the use of fondaparinux (RR 0.90, 95% CI 0.80 to 1.01, P = 0.07; Analysis 1.1), possibly attributed to the large sample size and weight of the enoxaparin subgroup (RR 0.85, 95% CI 0.73 to 0.98, P = 0.03; Analysis 1.1). However, a reduction of all-cause mortality at 90 to180 days from two trials involving 26,512 subjects was more evident (RR 0.89, 95% CI 0.81 to 0.97; Analysis 1.2), with a NNTB of 126 (95% CI 75 to 506), possibly due to the large sample size and weight of Yusuf 2006 OASIS 5 (RR 0.90, 95% CI 0.80 to 1.00, P = 0.05). Non-fatal AMI or re-infarction at 9 and 30 days Only one trial reported the incidences of AMI or re-infarction at nine days (Yusuf 2006 OASIS 6). Fondaparinux showed a beneficial effect compared to UFH (RR 0.69, 95% CI 0.47 to 1.01, P = 0.06; Analysis 1.3). However, no significant difference was Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 18 seen between fondaparinux and enoxaparin (two trials for 21,216 subjects; Simoons 2004; Yusuf 2006 OASIS 5). Data on non-fatal AMI and re-infarction at 30 days were available from three studies reporting a total of 26,638 patients (Coussement 2001; Yusuf 2006 OASIS 5; Yusuf 2006 OASIS 6). Fondaparinux were not superior to UFH or enoxaparin in reducing the risk of non-fatal AMI or re-infarction at 30 days (RR 0.92, 95% CI 0.81 to 1.04, P = 0.20; Analysis 1.4). Secondary clinical outcomes Combined endpoint of all-cause mortality, non-fatal AMI or re-infarction at nine days A total of three trials (27,650 participants) reported combined endpoint of all-cause mortality, non-fatal AMI or re-infarction at nine days (Simoons 2004; Yusuf 2006 OASIS 5; Yusuf 2006 OASIS 6). However, they showed no statistically significant difference between fondaparinux and anticoagulants groups (RR 0.97, 95% CI 0.87 to 1.08, P = 0.60; Analysis 1.5). 95% CI 0.28 to 0.43, P = 0.00001; Analysis 1.8), with a risk difference of 2% and a NNTB of 50 (95% CI 48 to 59). Efficacy and safety of low dose fondaparinux All-cause mortality at 30 days Separate analysis was conducted to study the effect of low dose fondaparinux on all-cause mortality at 30 days. Data from four studies (n=27,357) showed no statistically significant difference between treatment groups (RR 0.92, 95% CI 0.75 to 1.12, P= 0.40; Analysis 2.1). Non-fatal AMI or re-infarction at 30 days Simiarly, we analysed the effect of low dose fondaparinux on the risk of non-fatal AMI or re-infarction at 30 days (n=26,678). No statistically significant difference was found between the fondaparinux and the anticoagulants groups (RR 0.90, 95% CI 0.65 to 1.23, P = 0.10; Analysis 2.2). Adverse effects Major bleeding at nine days Major bleeding at 9 and 30 days Major bleeding at 9 days was reported in three trials of 27,650 participants (Simoons 2004; Yusuf 2006 OASIS 5; Yusuf 2006 OASIS 6). Substantial heterogeneity was observed and the random effects model was applied. There was no signifIcant difference on the risk of major bleeding at nine days between the fondaparinux and the anticoagulants groups (RR 0.74, 95% CI 0.42 to 1.31, P = 0.30; Analysis 1.6). Two trials studied the risk of major bleeding at 30 days ( Coussement 2001; Yusuf 2006 OASIS 5). There was no statistically significant difference on the risk of major bleeding at 30 days between fondaparinux and UFH (RR 1.41, 95% CI 0.49 to 4.10, P = 0.53; Analysis 1.7). However, fondaparinux was associated with a 37% reduction in the risk of major bleeding at 30 days when compared to enoxaparin (RR 0.63, 95% CI 0.55 to 0.73, P = 0.0001; Analysis 1.7), with a risk reduction of 2% (95% CI 1% to 2%) and a NNTB of 50 (95% CI 50 to 100). All four trials reported the effect of low dose fondaparinux on major bleeding at nine days (Coussement 2001; Simoons 2004; Yusuf 2006 OASIS 5; Yusuf 2006 OASIS 6). Our meta-analysis showed no statistically significant difference between fondaparinux and anticoagulants (RR 0.75, 95% CI 0.45 to 1.26, P = 0.28; Analysis 2.3). Efficacy and safety of fondaparinux in PCI All-cause mortality at 30 days Yusuf 2006 OASIS 5 and Yusuf 2006 OASIS 6 (n=9,945) reported the all-cause mortality rate at 30 days associated with the use of fondaparinux in PCI. Our meta-analysis showed no significant reduction of mortality by fondaparinux (RR 1.05, 95% CI 0.83 to 1.32, P = 0.68; Analysis 3.1). Minor bleeding at 30 days Coussement 2001 and Yusuf 2006 OASIS 5 reported the risk of minor bleeding at 30 days, comparing fondaparinux against UFH and enoxaparin, respectively. Meta-analysis of the two trials showed no significant effect with fondaparinux (RR 0.70, 95% CI 0.14 to 3.39, P = 0.65; Analysis 1.8). However, Yusuf 2006 OASIS 5 (20,078 participants) reported a significant low risk of minor bleeding with fondaparinux compared with enoxaparin (RR 0.34, Non-fatal AMI and re-infarction at 30 days Yusuf 2006 OASIS 5 and Yusuf 2006 OASIS 6 (n=9,945) also compared the effect of fondaparinux compared to UFH and enoxaparin on infarction and re-infarction at 30 days. No statistically significant difference was observed between the treatment groups (RR 1.08, 95% CI 0.89 to 1.30, P = 0.42; Analysis 3.2). Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 19 Meta-analysis of data on major bleeding at nine days from Yusuf 2006 OASIS 5 and Yusuf 2006 OASIS 6 (n=9,945) showed no difference on risk of bleeding with the administration of fondaparinux compared against UFH and enoxaparin (RR 0.76, 95% CI 0.28 to 2.05, P = 0.59; Analysis 3.3). However, fondaparinux was associated with a lower risk of bleeding when compared against enoxaparin in Yusuf 2006 OASIS 5 (RR 0.47, 95% CI 0.35 to 0.61, P < 0.00001). Since arterial thrombosis has a principal role in ACS, antithrombotic therapy is pivotal to avoid total or partial vessel occlusion by the developing thrombus (Maan 2009). UFH has been the main antithrombotic agent to reduce the occurrence of major ischemic events in ACS for nearly 60 years, but its usage requires careful monitoring and adverse effects include thrombocytopenia and osteoporosis (ACCP 2008). This prompted the development of new antithrombotic agents such as LMWH and factor Xa inhibitors (ACCP 2008; Eikelboom 2010; Harm 2007; Hirsh 2007). Catheter thrombosis Summary of main results We also analysed the difference in catheter thrombosis associated with fondaparinux and anticoagulants in PCI. Catheter thrombosis was more common in the fondaparinux group in both Yusuf 2006 OASIS 5 (n=6,238) and Yusuf 2006 OASIS 6 (n=3,768) although the overall effect was not statistically significant (RR 9.42, 95% CI 0.64 to 139.63, P = 0.10; Analysis 3.4). A number of studies evaluating the role of factor Xa inhibitors in ACS has not been included in our review because their methodological characteristics were not suitable (Alexander 2005; Cohen 2007) or because trial data are yet to be published (e.g. Sabatine 2009). Therefore, our review is not a complete representation of all the available evidence on the clinical efficacy and safety profiles of factor Xa inhibitors. Fondaparinux, an indirect factor Xa inhibitor, when administrated in the beginning of ACS development (six to eight days) showed an effect in reducing all-cause mortality at 30 days compared against enoxaparin, but we concluded that there was possibly no significant impact on the clinical outcome. However, a long-term reduction of mortality at 90 to 180 days was apparent, especially when compared to enoxaparin, resulting in an NNTB of at least 126. Fondaparinux did not reduce the risk of non-fatal AMI or re-infarction at 9 and 30 days, neither did it reduce the incidence of combined endpoint of all-cause mortality and non-fatal AMI at nine days. Use of low dose fondaparinux showed equivalent effect in reducing the risk of all-cause mortality, non-fatal AMI or reinfarction at 9 days to UHF or enoxaparin. For participants undergoing PCI, fondaparinux demonstrated similar clinical efficacy on the risk of all-cause mortality, non-fatal AMI or re-infarction at 30 days to UFH or enoxaparin. On the other hand, an increased risk of catheter thrombosis was clearly associated with the use of fondaparinux. Our results indicate that the factor Xa inhibitor fondaparinux might be a safe alternative to enoxaparin in terms of the risk of minor and major bleeding at 30 days, but this was not evident when compared to UFH. This could be useful amidst concerns associated with an increased risk of bleeding related to their use (Brown 2007). Major bleeding at nine days Sensivity Analyses Sensivity analyses were conducted to evaluate the impact of heterogeneity by excluding studies with methodological discordance against the majority of the studies taking part in the evaluation. A few interesting findings: All-cause mortality at 30 days When studies with high levels of heterogeneity were excluded ( Coussement 2001; Simoons 2004), the effect of fondaparinux on all-cause mortality at 30 days became statistically significant (RR 0.89; 95% CI 0.79 to 1.00; P = 0.05; Analysis 4.1). The effect was more apparently in Yusuf 2006 OASIS 5 where enoxaparin was used as the control drug (RR 0.84; 95% CI 0.72 to 0.97; P = 0.02; Analysis 4.1). Major bleeding at nine days Simiarly, we excluded Coussement 2001 and Simoons 2004 which are studies with high heterogeneity from the analyses. The remaining studies Yusuf 2006 OASIS 5 and Yusuf 2006 OASIS 6, both of which used low doses of fondaparinux, did not show a significant benefit reducing the adverse event at nine days (RR 0.69, 95% CI 0.39 to 1.21, P = 0.19; Analysis 4.2). Lower risk of major bleeding was shown to be associated with the use of fondaparinux in Yusuf 2006 OASIS 5 where enoxaparin was the control drug (RR 0.53; 95% CI 0.45 to 0.62; P < 0.00001; Analysis 4.2). DISCUSSION Overall completeness and applicability of evidence In addition to their clinical effectiveness and safety profile, the newer antithrombotic agents need to be more economically attractive than UFH (Nutescu 2006). Health economic analyses on fondaparinux have been limited to secondary cost-effectiveness Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 20 analyses, based on data from published RCT as well as analytical models such as decision trees or Monte Carlo modelling; fondaparinux appeared to be cost-effective in participants with nonSTEMI when compared against enoxaparin (Latour-Perez 2009; Maxwell 2009; Yusuf 2006 OASIS 5). Quality of the evidence The limitations related to the assignment of the participants to one of the two control groups in Yusuf 2006 OASIS 6 and the lack of blinding of participants in Coussement 2001 could be potential sources of bias. The external validity in Yusuf 2006 OASIS 6 could be affected because the stratification of the control group to receive UFH or placebo was achieved based on the investigator’s judgment other than randomization. In Coussement 2001, absence of blinding led to an adjusted dose-finding study. Nevertheless, in both cases, the confidence in the resulting outcomes of interest seemed not to be affected by these shortcomings in our analyses. The presence of heterogeneity in some of the outcome analyses could be explained by the diverse methodological designs of the studies, including varied agents used in the treatment and control groups, as well as different co-morbidities in the included participants. All the studies were sponsored by pharmaceutical companies associated with the study drug, or the authors received research support or consultant fees from the pharmaceutical companies related to it. There was no rational evidence to suggest the results published could be seriously affected. Nonetheless, the data presented should be interpreted with caution. Potential biases in the review process A broad and systematic literature search for potentially relevant studies was performed. This was followed by careful selection of eligible studies based on set inclusion/exclusion criteria. We evaluated the risk of publication bias using funnel plots. However, interpretation of these should be done cautiously because the number of studies included in relation to our selection criteria was limited. Therefore, although there was asymmetry in our funnel plots, it was possibly due to methodological heterogeneity and not due to publication bias. UFH and enoxaparin in reducing the risk of death, AMI, re-infarction, or recurrence of ischemia at 30 days. However, substantial reduction was seen in mortality rates at 180 days as well as in major and minor bleeding when factor Xa inhibitors were compared to enoxaparin. This reduced association of factor Xa inhibitors with adverse bleeding was thought to be caused by two potential factors: a lack of thrombin interference, or the relatively low dose that were deemed effective compared to standard enoxaparin dosage (ACC/AHA 2007; Bonaca 2009; Karthikeyan 2009). Published reviews on the role of factor Xa inhibitors in ACS all commented on their use in patients undergoing PCI as well as cost effectiveness (ACCP 2008; Barantke 2008; Bonaca 2009; Karthikeyan 2009). The increased risk of catheter thrombosis associated with factor Xa inhibitors in the patients undergoing PCI could be explained by the unavoidable contact-pathway activation triggered by contact of the blood to catheters during PCI. This finding is in agreement with ours. UFH was useful in inhibiting contact coagulation through factors XIa and XIIa inhibition (Bonaca 2009; Karthikeyan 2009). Consequently, it was recommended that fondaparinux should be administered in adjunction to UFH for patients undergoing invasive treatments such as PCI (ACC/AHA 2007; ACC/AHA 2008; ESC Guideline 2007; ESC Guidelines 2008). Nevertheless, more substantial data from wellplanned trials in appropriate settings are needed. AUTHORS’ CONCLUSIONS Implications for practice The findings of this systematic review suggest that administration of fondaparinux appeared to be at least as effective as UFH and enoxaparin in ACS, with the added benefit of a reduced risk of long-term mortality at six months and reduced rates of adverse effects (major and minor bleeding). However, we need to emphasize that more evidence, specifically about their clinical and safety profile in populations with a higher risk of thrombotic or bleeding complications (e.g. those receiving concomitant treatment with drugs affecting the coagulation process, those undergoing revascularization and the elderly), are required (Alexander 2007a; Alexander 2007b; Maan 2009). Implications for research Agreements and disagreements with other studies or reviews Numerous overviews have recently focused on the potential role of factor Xa inhibitors in ACS by reviewing studies that have investigated the clinical effectiveness and safety of these new agents (Barantke 2008; Bonaca 2009). Similar to our findings, these overviews concluded that factor Xa inhibitors were not inferior to New clinical trials, some of them on development, evaluating the following items should be considered: • The efficacy and safety of the use of the factor Xa inhibitors associated with glycoprotein (GP) IIa/IIIb inhibitors, in order to explore their safety profile when they are combined with drugs which could also affect platelet aggregation and so interfere with the coagulation process Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 21 • Fatal and non-fatal outcomes related to the use of factor Xa inhibitors in patients undergoing to revascularization therapy, especially PCI, and in subgroups with increased risk of bleeding such as the elderly • Head-to-head studies on the efficacy and safety of the different types of factor Xa inhibitors (direct and indirect), in order to investigate potential relationship between their clinical efficacy and safety profiles and drug types. We would like to thank the following persons for their great help with preparing this review: Mr Daniel Comandé, reference librarian of the Coordinating Centre of the Ibero-American Cochrane Network in the Argentine Institute for Clinical Effectiveness and Health Policy. Ms Margaret Burke and Ms Nicole Ackermann from the Cochrane Heart Group, for their help with preparing the protocol. Ms Janet Wale from the Cochrane Consumer Network, for her contribution in the plain language summary elaboration. Professor Dr Lerman Jorge for his initial contributions to this meta-analyses. ACKNOWLEDGEMENTS REFERENCES References to studies included in this review Coussement 2001 {published data only} Coussement PK, Bassand JP, Convens C. A synthetic factor-xa inhibitor (ORG31540/SR9017A) as an adjunct to fibrinolysis in acute myocardial infarction: the Pentalyse study. European Heart Journal 2001;22(18):1716–24. Simoons 2004 {published data only} Simoons ML, Bobbink IW, Boland J, Gardien M, Klootwijk P, Lensing AW, et al.A dose-finding study of fondaparinux in patients with non-ST-segment elevation acute coronary syndromes: the Pentasaccharide in Unstable Angina (PENTUA) Study. Journal of the American College of Cardiology 2004;43(12):2183–90. Yusuf 2006 OASIS 5 {published data only} Fox KA, Bassand JP, Mehta SR. Influence of renal function on the efficacy and safety of fondaparinux relative to enoxaparin in non ST-segment elevation acute coronary syndromes. Annals of Internal Medicine 2007;147(5): 304–10. Genth-Zotz S, Rupprecht HJ, Mehta SR. Abstract Nª V1744: Early benefit of fondaparinux in patients with non-ST elevation acute coronary syndromes: a secondary analysis of the OASIS 5 trial. Clinical Research in Cardiology 2007;96:Suppl 1. Mehta SR, Granger CB, Eikelboom JW. Efficacy and safety of fondaparinux versus enoxaparin in patients with acute coronary syndromes undergoing percutaneous coronary intervention: results from the OASIS-5 trial. Journal of the American College of Cardiology 2007;50(18):1742–51. Mehta SR, Yusuf S, Granger CB. Design and rationale of the MICHELANGELO Organization to Assess Strategies in Acute Ischemic Syndromes (OASIS)-5 trial program evaluating fondaparinux, a synthetic factor xa inhibitor, in patients with non-ST-segment elevation acute coronary syndromes. American Heart Journal 2005;150(6):1107. Sculpher MJ, Lozano-Ortega G, Sambrook J, et al.Fondaparinux versus Enoxaparin in non ST-elevation acute coronary syndromes: Short-term cost and long-term cost-effectiveness using data from the Fifth Organization to Assess Strategies in Acute Ischemic Syndromes Investigators (OASIS-5) trial. American Heart Journal 2009;157(5): 845–52. ∗ Yusuf S, Mehta SR, Chrolavicius S. Comparison of fondaparinux and enoxaparin in acute coronary syndromes. New England Journal of Medicine 2006;354(14):1464–76. Yusuf 2006 OASIS 6 {published data only} Oldgren J, Wallentin L, Afzal R. Effects of fondaparinux in patients with ST-segment elevation acute myocardial infarction not receiving reperfusion treatment. European Heart Journal 2008;29(3):315–23. Peters RJ, Joyner C, Bassand JP. The role of fondaparinux as an adjunct to thrombolytic therapy in acute myocardial infarction: a subgroup analysis of the OASIS-6 trial. European Heart Journal 2008;29(3):324–31. ∗ Yusuf S, Mehta SR, Chrolavicius S. Effects of fondaparinux on mortality and reinfarction in patients with acute STsegment elevation myocardial infarction: the OASIS-6 randomized trial. JAMA 2006;295(13):1519–30. References to studies excluded from this review Alexander 2005 {published data only} Alexander JH, Yang H, Becker RC. First experience with direct, selective factor xa inhibition in patients with non-ST-elevation acute coronary syndromes: Results of the XANADU-ACS Trial. Journal of Thrombosis and Haemostasis 2005;3(3):439–47. Cohen 2007 {published data only} Cohen M, Bhatt DL, Alexander JH. Randomized, doubleblind, dose-ranging study of otamixaban, a novel, parenteral, short-acting direct factor xa inhibitor, in percutaneous coronary intervention: the SEPIA-PCI trial. Circulation 2007;115(20):2642–51. Mehta 2007 {published data only} Mehta SR, Steg PG, Granger CB. Randomized, blinded trial comparing fondaparinux with unfractionated heparin in Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 22 patients undergoing contemporary percutaneous coronary intervention: Arixtra Study in Percutaneous Coronary Intervention: a Randomized Evaluation (ASPIRE) Pilot Trial. Circulation 2007;111(11):1390–7. Vuillemenot 1999 {published data only} Vuillemenot A, Schiele F, Meneveau N. Efficacy of a synthetic pentasaccharide, a pure factor Xa inhibitor, as an antithrombotic agent--a pilot study in the setting of coronary angioplasty. Thrombosis and Haemostasis 1999;81 (2):214–20. References to studies awaiting assessment Oasis 8 {published data only} NCT00790907. Fondaparinux Trial With UFH During Revascularization in Acute Coronary Syndromes (FUTURA/OASIS 8). http://clinicaltrials.gov/ct2/show/ NCT00790907 (accessed 18 March 2010). Sabatine 2009 {published data only} Sabatine MS, Antman EM, Widimsky P, Ebrahim IO, Kiss RG, Saaiman A, et al.Otamixaban for the treatment of patients with non-ST-elevation acute coronary syndromes (SEPIA-ACS1 TIMI 42): a randomised, double-blind, active-controlled, phase 2 trial. Lancet 2009;374(9692): 787–95. [: NCT00317395] Additional references ACC/AHA 2007 Anderson JL, Adams CD, Antman EM, Bridges CR, Califf RM, Casey DE Jr, et al.ACC/AHA 2007 Guidelines for the management of patients with unstable angina/non-STelevation myocardial infarction. Journal of the American College of Cardiology 2007;50(7). ACC/AHA 2008 Antman EM, Hand M, Armstrong PW, Bates ER, Green LA, Halasyamani LK, et al.2007 Focused Update of the ACC/AHA 2004 Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction. Circulation 2008;117(2):296–329. ACC/AHA 2009 Kushner FG, Hand M, Smith SC Jr, King SB 3rd, Anderson JL, Antman EM, et al.2009 Focused Updates: ACC/ AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction (updating the 2004 Guideline and 2007 Focused Update) and ACC/AHA/ SCAI Guidelines on Percutaneous Coronary Intervention (updating the 2005 Guideline and 2007 Focused Update). Circulation 2009;122(22):2271–306. in the elderly, part I: Non-ST-segment-elevation acute coronary syndromes: a scientific statement for healthcare professionals from the American Heart Association Council on Clinical Cardiology: in collaboration with the Society of Geriatric Cardiology. Circulation 2007;115(19):2549–69. Alexander 2007b Alexander KP, Newby LK, Armstrong PW, Cannon CP, Gibler WB, Rich MW, et al.Acute coronary care in the elderly, part II: ST-segment-elevation myocardial infarction: a scientific statement for healthcare professionals from the American Heart Association Council on Clinical Cardiology: in collaboration with the Society of Geriatric Cardiology. Circulation 2007;115(19):2570–89. Barantke 2008 Barantke M, Bonnemeier H. Factor Xa inactivation in acute coronary syndrome. Current Pharmaceutical Design 2008; 14:1186–90. Bassand 2008 Bassand JP. The place of fondaparinux in the ESC and ACC/AHA guidelines for anticoagulation in patients with non-ST elevation acute coronary syndromes. European Heart Journal Supplements 2008;Suppl 10:C22–9. Blick 2008 Blick SA, Orman JS, Wagstaff A. Fondaparinux Sodium. American Journal of Cardiovascular Drugs 2008;8(2): 113–25. Bonaca 2009 Bonaca MP, Steg PG, Feldman LJ, Canales JF, Ferguson JJ, Wallentin L, et al.Antithrombotics in acute coronary syndromes. Journal of the American College of Cardiology 2009;54(11):969–84. Brown 2007 Brown CH. A new era of anticoagulation. Factor xa and direct thrombin inhibitors. US Pharmacist 2007;32(3): 35–48. Cannon 2001 Cannon CP, Battler A, Brindis RG, Cox JL, Ellis SG, Every NR, et al.American College of Cardiology key data elements and definitions for measuring the clinical management and outcomes of patients with acute coronary syndromes. A report of the American College of Cardiology Task Force on Clinical Data Standards (Acute Coronary Syndromes Writing Committee). Journal of the American College of Cardiology 2001;38(7):2114–30. Comp 2003 Comp PC. Selective factor xa inhibition improves efficacy of venous thromboembolism prophylaxis in orthopedic surgery. Pharmacotherapy 2003;23(6):772–87. ACCP 2008 Hirsh J, Guyatt G, Albers GW, Harrington R, Schünemann HJ. Executive Summary: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008;133(6):71S-105S. [DOI: 10.1378/ chest.08-0693] Crowther 2004 Crowther M, Weitz JI. New anticoagulants: an update. Clinical Advances in Hematology & Oncology 2004;2(11): 743–9. Alexander 2007a Alexander KP, Newby LK, Cannon CP, Armstrong PW, Gibler WB, Rich MW, et al.Acute coronary care Davies 2000 Davies MJ. The pathophysiology of acute coronary syndromes. Heart 2000;83:361–6. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 23 Eikelboom 2010 Eikelboom W, Weitz JI. Update on antithrombotic. Therapy new anticoagulants. Circulation 2010;121: 1523–32. ESC Guideline 2007 Bassand JP, Hamm CW, Ardissino D, et al.Guidelines for the diagnosis and treatment of Non-ST-segment elevation acute coronary syndromes.The Task Force for the Diagnosis and Treatment of Non-ST-SegmentElevation Acute Coronary Syndromes of the European Societyof Cardiology. European Heart Journal 2007;28:1598-660. ESC Guidelines 2008 Van de Werf F, Bax J, Betriu A, Blomstrom-Lundqvist C, Crea F, Falk V, et al.Management of acute myocardial infarction in patients presenting with persistent ST-segment elevationThe Task Force on the management of ST-segment elevation acute myocardial infarction of the European Society of Cardiology. European Heart Journal 2008;29: 2909-45. Franchini 2005 Franchini M. Heparin-induced thrombocytopenia: an update. Thrombosis Journal 2005;3:14. Goodman 2008 Goodman SG, Menon V, Cannon CP, Steg G, Ohman EM, Harrington RA, et al.Acute ST-Segment Elevation Myocardial Infarction: American College of Chest Physicians Evidence-Based Clinical PracticeGuidelines (8th Edition). Chest 2008;133(6 Suppl):708S-75S. Hamm 2000 Hamm CW, Braunwald E. A classification of unstable angina revisited. Circulation 2000;102(1):118–22. Harm 2007 Harm Wienbergen, Uwe Zeymer. Management of acute coronary syndromes with fondaparinux. Vascular Health and Risk Management 2007;3(3):329. Higgins 2009 Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.2 [updated September 2009]. The Cochrane Collaboration, 2009. Available from www.cochrane-handbook.org. Hirsh 2005 Hirsh J, O’Donnell M, Weitz JI. New anticoagulants. Blood 2005;105(2):453–63. Hirsh 2007 Hirsh J, O’Donnell M, Eikelboom JW. Beyond unfractionated heparin and warfarin current and future advances. Circulation 2007;116:552–60. Karthikeyan 2009 Karthikeyan G, Mehta SR, Eilelboom JW. Fondaparinux in the treatment of acute coronary syndromes: evidence from Oasis 5 and 6. Expert review of cardiovascular therapy 2009; 7(3):241–9. Latour-Perez 2009 Latour-Perez J, de-Miguel-Balsa E. Cost effectiveness of fondaparinux in non-ST-elevation acute coronary syndrome. Pharmacoeconomics 2009;27(7):585–95. Lim 2006 Lim W, Dentali F, Eikelboom JW, Crowther MA. Metaanalysis: low-molecular-weight heparin and bleeding in patients with severe renal insufficiency. Annals of Internal Medicine 2006;144(9):673–84. Linkins 2005 Linkins LA, Weitz JI. New anticoagulant therapy. Annual Review of Medicine 2005;56:63–77. Maan 2009 Jokhadar M, Wenger NK. Review of the treatment of acute coronary syndrome in elderly patients. Clinical Interventions in Aging 2009;4:435–44. Maxwell 2009 Maxwell CD, Holdford DA, Crouch MA. Cost effectiveness analysis of anticoagulation strategies in Non ST elevation acute coronary syndromes. Annals of pharmacotherapy 2009; 43(4):586–95. McCaan 2008 McCann CJ, Menown IBA. New anticoagulant strategies in ST elevation myocardial infarction: Trials and clinical implications. Vascular Health and Risk Management 2008;4 (2):305–13. Nutescu 2006 Nutescu EA. Easing the economic burden of acute coronary syndromes: cost-effectiveness of emerging therapies. American Journal of Managed Care 2006;12(Suppl): S444–50. Warkentin 2008 Warkentin TE, Greinacher A, Koster A, Lincoff AM, American College of Chest Physicians. Treatment and prevention of heparin-induced thrombocytopenia: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008;133 (6 Suppl):340S–380S. ∗ Indicates the major publication for the study Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 24 CHARACTERISTICS OF STUDIES Characteristics of included studies [ordered by study ID] Coussement 2001 Methods Allocation using an interactive voice randomisation system Phase II Study, randomised, open label Study aim: To prove the hypothesis that factor Xa inhibition with pentasaccharide would be an effective and safe antithrombotic therapy in conjunction with alteplase and that prolonged administration of pentasaccharide may better prevent rethrombosis of the infarct related coronary artery Participants Total 333 participants with STEMI during the first six hours of evolution Twenty-four centres in Europe Fondaparinux: 4 mg Age (years) 61 (53, 68) GenderMale 85 Gender Female 15 Race Caucasian 98 Other 2 Current smoker 62 H/o of Hypertension 35 Hypercholesterolaemia 47 Prior infarction 16 Diabetes 9 Infarct-related artery LAD 37 RCA 47 LCX 15 Normal 1 Unknown 0 Fondaparinux: 8 mg Age (years) 55 (48, 66) GenderMale 83 Gender Female 17 Race Caucasian 100 Other 0 Current smoker 53 H/o of Hypertension 33 Hypercholesterolaemia 39 Prior infarction 8 Diabetes 12 Infarct-related artery LAD 40 RCA 47 LCX 15 Normal 1 Unknown 0 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 25 Coussement 2001 (Continued) Fondaparinux:12 mg Age (years) 59 (49, 67) Gender Male 83 Gender Female 17 Race Caucasian 100 Other 0 Current smoker 42 History of (H/o) Hypertension 28 Hypercholesterolemia 49 Prior infarction 11 Diabetes 8 Infarct-related artery Left anterior descendent (LAD) 36 Right coronary artery (RCA) 43 Left circumflex (LCX ) 17 Normal 1 Unknown 2 Fondaparinux: combined (4 mg-8 mg-12 mg) Age (years) 59 (50, 67) GenderMale 84 Gender Female 16 Race Caucasian 99 Other 1 Current smoker 52 H/o of Hypertension 32 Hypercholesterolemia 45 Prior infarction 12 Diabetes 10 Infarct-related artery LAD 38 RCA 46 LCX 15 Normal 1 Unknown1 UFH Age (years) 55 (48, 65) Gender Male 80 Gender Female 20 Race Caucasian 100 Other 0 Current smoker 59 H/o of Hypertension 25 Hypercholesterolaemia 34 Prior infarction 9 Diabetes 9 Infarct-related artery LAD 44 RCA 45 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 26 Coussement 2001 (Continued) LCX 11 Normal 0 Unknown 1 Data are shown as % for dichotomous variables and median (25, 75th percentile) for continuous variables. PS=pentasaccharide; UFH=unfractionated heparin. Interventions All patients received alteplase (ALT) over 90 minutes, the control group received a standard dose of UFH (Bolus of 5000 previous ALT+ 1000U.H during 48-72 hrs) adjusted to APTT 50-70 seconds. Experimental groups low dose (4 mg or 6 mg if >90 kg-/ medium dose-8 mg or 6 mg if < 60 kg or 10 mg if >90 kg-) or high dose (12 mg or 10 mg if< 60 KG ) of fondaparinux (ORG 31540/SR 9017 A) administered daily during 5 to 7 days. First doses were given intravenously previously to ALTEPLASE then subcutaneously All participants were given aspirin (150 - 325 mg). Outcomes TIMI flow in artery related to myocardial infarction at 90 MIN and on 5th and 7th days Clinical efficacy end points: all- cause mortality, reinfarction, urgent revascularization Final safety end point bleeding. Notes UFH compared to fondaparinux in STEMI during the first 6 hrs. in pts receiving thrombolytic treatment Pentalyse STEMI UFH All participants thrombolysis- TIMI flow evaluated at 90min/ days 5 and 7 Clinical efficacy end points through 30 days. 98.7% of the participants received at least one dose of the study drug Sponsorship Sanofi Synthelabo Risk of bias Item Authors’ judgement Description Adequate sequence generation? Yes Interactive voice randomisation system Allocation concealment? Yes By the use of the interactive voice randomisation system Blinding? All outcomes No Open-label dose finding trial without blinding of participants and personnel but the angiographic efficacy end- points were evaluated by the angiographic core laboratory which remained blinded to the allocated treatment. Even though the outcome assessors of angiographic efficacy end-point were blinded, the report of some clinical ef- Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 27 Coussement 2001 (Continued) ficacy ones such as urgent revascularization needed or the minor safety end-point any bleeding could likely be influenced by the lack of blinding of some personnel Incomplete outcome data addressed? All outcomes Yes 326/333 of the enrolled participants received the study medication, this population was considered the intention to treat population for analysis of the clinical endpoints No missing data of clinical events through day 30 in the 326 participants, and in those 101 pts who underwent coronary interventions at 90 minutes Free of selective reporting? Yes Study financially supported by Sanofi Synthelabo, but there is insufficient rationale or evidence that this situation could have introduced bias Free of other bias? Yes The study appears to be free of other sources of bias. Simoons 2004 Methods Study Phase II. Pts randomised to one of four doses of fondaparinux dosages or enoxaparin in blocks of five through a central computerized service. Treatment was doubleblind, using a double-dummy technique, and was administered for a minimum of three days and a maximum of seven days, to allow revascularization procedures or early patient discharge Study aim: To compare for different dosages of fondaparinux with the LMWH enoxaparin in patients with Non ST segment elevation acute coronary syndromes through a dose- finding study Participants Total 1138 participants older than 21 years old without persistent ST elevation, with rest angina or at minimum movements and with the last episode during the 24 hrs previous to be enrolled and with ST dynamic changes or ST depression ≥ 0.1mV and / or troponin T or I concentrations > 0.1 ng/ml Fondaparinux: 2.5 mg Intention-to-treat population (n) 229 Mean age (y.o) 62.3 Male gender (%) 63.8 Mean body weight (kg) 78.4 Clinical characteristics Dynamic ST-segment depression (%) 46.3; ST-segment depression (%) 55.9 Troponin-positive (%) 42.7 History of Myocardial infarction (%) 24.6 Angina (%) 52.6 Heart failure (%) 6.1 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 28 Simoons 2004 (Continued) PTCA (%) 6.1 CABG (%) 9.2 Hypertension (%) 50.4 Hypercholesterolemia (%) 43.9 Diabetes (%) 21.5 Currently smoking (%) 25.9 Fondaparinux: 4 mg Intention-to-treat population (n) 220 Mean age (y.o) 61.3 Male gender (%) 63.6 Mean body weight (kg) 79.3 Clinical characteristics Dynamic ST-segment depression (%) 46.8 ST-segment depression (%) 58.6 Troponin-positive (%) 38.7 History of Myocardial infarction (%) 36.1 Angina (%) 59.8 Heart failure (%) 5.9 PTCA (%) 17.4 CABG (%) 9.1 Hypertension (%) 47.0 Hypercholesterolemia (%) 46.1 Diabetes (%) 14.6 Currently smoking (%) 35.6 Fondaparinux: 8 mg Intention-to-treat population (n) 225 Mean age (y.o) 62.0 Male gender (%) 65.8 Mean body weight (kg) 78.1 Clinical characteristics Dynamic ST-segment depression (%) 46.8 ST-segment depression (%) 52.9 Troponin-positive (%) 44.9 History of Myocardial infarction (%) 21.6 Angina (%) 53.6 Heart failure (%) 5.0 PTCA (%) 8.6 CABG (%) 11.3 Hypertension (%) 51.8 Hypercholesterolemia (%) 45.9 Diabetes (%) 17.1 Currently smoking (%) 31.8 Fondaparinux:12 mg Intention-to-treat population (n) 234 Mean age (y.o) 61.1 Male gender (%) 70.5 Mean body weight (kg) 79.1 Clinical characteristics Dynamic ST-segment depression (%) 48.7 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 29 Simoons 2004 (Continued) ST-segment depression (%) 50.0 Troponin-positive (%) 40.2 History of Myocardial infarction (%) 28.4 Angina (%) 53.0 Heart failure (%) 4.2 PTCA (%) 9.7 CABG (%) 5.1 Hypertension (%) 50.0 Hypercholesterolemia (%) 46.6 Diabetes (%) 14.4 Currently smoking (%) 34.7 Enoxaparin: 1 mg/kg Intention-to-treat population (n) 230 Demographics Mean age (y.o) 60.3 Male gender (%) 67.4 Mean body weight (kg) 79.2 Clinical characteristics Dynamic ST-segment depression (%) 46.5 ST-segment depression (%) 52.6 Troponin-positive (%) 37.7 History of Myocardial infarction (%) 21.4 Angina (%) 51.5 Heart failure (%) 3.5 PTCA (%) 14.8 CABG (%) 8.3 Hypertension (%) 47.6 Hypercholesterolemia (%) 45.9 Diabetes (%) 16.6 Currently smoking (%) 29.7 y.o years old; CABG coronary artery bypass graft surgery; PTCA percutaneous coronary intervention Interventions Participants randomised to one of four fondaparinux doses (2.5 mg; 4 mg; 8 mg, or 12 mg) O.D or Enoxparin 1 mg TD, minimum three days maximum seven days to allow revascularization or early discharge At enrolment in the study, 58% of patients had already received aspirin, 42% had received HFH or LMWH, and 5% had received lipid-lowering drugs. The fondaparinux and enoxaparin treatment groups were comparable regarding these characteristics. After randomisation, all patients received aspirin and most patients received nitrates (95%) and beta-blockers (91%). Lipid-lowering drugs were given in 54%; angiotensin-converting enzyme inhibitors in 45%, calcium channel blockers in 40%, thienopyridines in 19%, and glycoprotein IIb/IIIa receptor blockers in 3.4% of patients. There were no significant differences in medication among the treatment groups Outcomes Clinical efficacy: Primary final end-point composite of mortality nor related to bleeding, AMI, or recurrent symptomatic or asymptomatic myocardial ischemia till day nine. Secondary end- point: each of the primary end-points but individually and revascularization at 30 days Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 30 Simoons 2004 (Continued) Primary safety end point : major bleeding till day nine. Secondary safety end point: minor bleedings. Notes Fondaparinux versus enoxaparin in Non-STEMI up to 30 days after the event This report describes the efficacy and safety results according to the intention-to-treat group (N1,138), as well as a per-protocol analysis (N 929), but only the first was consider in the meta- analyses 82% of the information was complete during follow-up Sponsorship Organon y.o years old; O.D once a daily; TD: twice daily Risk of bias Item Authors’ judgement Description Adequate sequence generation? Yes Patients were randomised to one of four fondaparinux dosages or enoxaparin in blocks of five through a central computerized service Allocation concealment? Yes Central computerized allocation Blinding? All outcomes Yes Treatment was double blind using a double dummy technique. To ensure double blinding (double dummy) fondaparinux treated patients also received placebo- enoxaparin injections twice daily, and enoxaparin-treated patients received a placebo- fondaparinux injection once daily with the first dose given intravenously All potential study outcomes were reviewed by a central adjudication committee,and ECG recordings were analysed by a central core laboratory. Both were blinded as to patient allocation Incomplete outcome data addressed? All outcomes Yes The analysis was by the intention to treat principle for all randomised patients. In addition a per- protocol analysis for the primary efficacy endpoint (composite of mortality, acute myocardial infarction, or recurrent symptomatic or asymptomatic ischemia up to day nine), was defined with exclusion of patients with incomplete administration of study treatment (N=22) , use of prohibited concomitant medication (N=110), or inadequate continuous ECG monitoring defined as less than 12 hrs Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 31 Simoons 2004 (Continued) recording (N=71).Safety analysis was based on all patients who received study medication Free of selective reporting? Yes The study was financially supported by Organon but the evidence is not enough to sustain that this situation could be bias related. The data were presented for all randomised patients - intention to treat population- and the per - protocol analysis Free of other bias? Yes No sources of bias are identified. Yusuf 2006 OASIS 5 Methods Randomised by a central telephone system. It was a double blind double dummy trial comparing fondaparinux to enoxaparin in pts with ACS Study aim: To compare the efficacy and safety of fondaparinux and enoxaparin in high risk patients with unstable angina or myocardial infarction without ST segment elevation Participants Total 20,078 participants from 576 centres in 41 countries with U.A or AMI without ST elevation. Pts were allocated in a randomised fashion to one of the treatments during the first 24 hrs following the symptoms, but at least two of the following criteria to be included: at least 60 y.o, elevated levels of CK-MB or troponin,or electrocardiographic changes secondary to myocardial ischemia Enoxaparin:(N = 10,021) Age - y.o 66.6±11.0 Male sex - no. (%) 6148 (61.4) Diagnosis at study entry - no. (%) Unstable angina 4517 (45.1) Suspected myocardial infarction 5502 (54.9) Medical history - no. (%) Myocardial infarction 2580 (25.7) CABG or PCI 1953 (19.5) Stroke 647 (6.5) Heart failure 1386 (13.8) Hypertension 6721 (67.1) Diabetes 2503 (25.0) Current or former smoker 5473 (54.6) Fondaparinux: (N = 10,057) Age - y.o 66.6±10.8 Male sex - no. (%) 6231 (62.0) Diagnosis at study entry - no. (%) Unstable angina 4581 (45.6) Suspected myocardial infarction 5474 (54.4) Medical history - no. (%) Myocardial infarction 2584 (25.7) CABG or PCI 2022 (20.1) Stroke 597 (5.9) Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 32 Yusuf 2006 OASIS 5 (Continued) Heart failure 1402 (13.9) Hypertension 6777 (67.4) Diabetes 2575 (25.6) Current or former smoker 5440 (54.1) y.o years old; CABG coronary by- pass graft Interventions Participants were randomised to fondaparinux 2.5 subcutaneously but 5 mg if PCI without glycoprotein IIB IIIa (GP IIB/ IIIA) was planned, or enoxaparin 1 mg/kg day subcutaneously TD for six days Randomisation was stratified according to the planned use of GP IIB/ IIIA, so the doses of UFH were100 u/KfgW/O GPIIBIIIA OR 65U/ KG with the use of inhibitors and if more than six hours has spent after the last dose of enoxaparin. If fondaparinux was going to be administrated and if the pt was going to a percutaneous intervention during the next six hours 2.5 or 5 mg of fondaparinux were administrated additionally related to the administration of glycoprotein inhibitors, but if more than six hours had spent those extra doses were given endovenously. Enoxaparin (%),n = 10021 Aspirin (ASA) 97.5 GPIIb/IIIa inhibitor 17.6 During PCI 41.0 Clopididogrel / ticlopidine 66.7 Beta-Blockers 87.7 Calcium channel blockers 26.8 IECA or ARB* 76.1 Statins 77.5 Fondaparinux (%),n = 10057 ASA 97.5 GPIIb/IIIa inhibitor 18.6 During PCI 41.7 Clopididogrel/ticlopidine 67.1 Beta-Blockers 87.1 Calcium channel blockers 26.9 IECA or ARB* 74.9 Statins 78.0 * Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers Outcomes Primary clinical efficacy end-point composed: death, MI or refractory ischemia and each individual component at 30 days and at the end of study. Safety outcome major bleeding at nine days Notes Fondaparinux compared to enoxaparin in participants suffering from Non-STEMI with symptoms in the last 24 hrs OASIS 5 follow up minimum 90 days, maximum 180 days. Assesing outcomes by a committee in a blinded fashion to the allocated treatment fondaparinux group 99.2% received at least once the study drug and the 99.4% in the enoxaparin group Sponsorship Sanofi-Synthelabo, Organon NV, and Glaxo-Smith-Kline Risk of bias Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 33 Yusuf 2006 OASIS 5 (Continued) Item Authors’ judgement Description Adequate sequence generation? Yes Patients were randomly assigned by means of a 24 hrs computerized central telephone system to receive either fondaparinux plus placebo enoxaparin or enoxaparin plus placebo fondaparinux Allocation concealment? Yes Allocation by a central telephone system according to a compute generated randomisation list stratified by centre Blinding? All outcomes Yes Double blind - Double dummy. So patients received either fondaparinux once daily plus placebo enoxaparin twice daily by subcutaneous injection or enoxaparin twice daily plus placebo fondaparinux once daily by subcutaneous injection. In case of percutaneous coronary intervention the double blind arrangement was maintained Incomplete outcome data addressed? All outcomes Yes “Vital status was ascertained for 20066 of the 20078 randomly assigned patients (99. 9%); seven patients in the fondaparinux group and five in the enoxaparin group were lost to follow - up by nine days” “At least one dose of allocated study drug was administered to 99.2% to the patients in the fondaparinux group and 99.4% of those in the enoxaparin group” Free of selective reporting? Yes The authors received research support or consultant fees from the pharmaceutical company related to the study drug, but there was insufficient rationale or evidence that this situation could have introduced bias Free of other bias? Yes No sources of bias were identified. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 34 Yusuf 2006 OASIS 6 Methods Randomised double blind trial evaluating fondaparinux against usual care in pts suffering from STEMI Study aim: To evaluate the impact of fondaparinux compared with standard approaches to antithrombotic therapy in a broad range of patients with STEMI in preventing the primary and composite outcome of death or reinfarction at 30 days Participants Total 12,092 participants suffering from STEMI enrolled in 447 centres in 41 countries during the first 24 hrs of initial symptoms. The window time was shortened to 12 hrs after 4300 participants, when results from trials evaluating the use of heparin in ACS were evaluated, but without an internal analyses of the OASIS trial Placebo or Unfractionated Heparin (n = 6056) Age, mean (SD),y.o 61.5 (12.2) Men, No. (%) 4353 (71.9) Medical history, No. (%) Current or former smoker 3467 (57.2) Hypertension 3307 (54.6) Diabetes 1064 (17.6) Heart failure 840 (13.9) Myocardial infarction 746 (12.3) Stroke 385 (6.4) CABG surgery or PCI 237 (3.9) Fondaparinux (n = 6036) Age, mean (SD),y.o 61.6 (12.3) Men, No. (%) 4393 (72.8) Medical history, No. (%) Current or former smoker 3552 (58.8) Hypertension 3274 (54.3) Diabetes 1064 (17.6) Heart failure 844 (14.0) Myocardial infarction 772 (12.8) Stroke 416 (6.9) CABG surgery or PCI 235 (3.9) y.o years old; CABG coronary artery by pass Interventions 6036 pUFts. were randomised to 2.5 mg of fondaparinux once daily subcutaneously till the 8th day, and 6056 were assigned to the control group. Randomization was stratified according to the investigator criteria about the administration of UFH or placebo so • STRATUM I (No UFH according to the investigator criteria) receiving fondaparinux vs placebo • STRATUM II ( UFH yes) receiving first fondaparinux dose by IV route, the rest subcutaneously vs a shoot of 60UI/kg of UFH followed by 12 UI/kg/ hour during 24 to 48 hours. Fondaparinux eight days or till discharge, UFH 24- 48 hours. Medications within seven days of randomisation, No. (%) Placebo or Unfractionated Heparin (n = 6056) Aspirin 3741 (61.8) Beta-Blockers 1593 (26.3) ACE inhibitor or ARB 1560 (25.8) Clopidogrel or ticlopidine 1006 (16.6) UFH 880 (14.5) Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 35 Yusuf 2006 OASIS 6 (Continued) Lipid-lowering agents 689 (11.4) Calcium channel blockers 598 (9.9) LMWH 107 (1.8) Gp IIb/IIIa receptor antagonist 117 (1.9) Bivalirudin or hirudin 2 (0.1) Fondaparinux (n = 6036) Aspirin 3728 (61.8) Beta-Blockers 1597 (26.5) ACE inhibitor or ARB 1516 (25.1) Clopidogrel or ticlopidine 957 (15.9) UFH 907 (15.0) Lipid-lowering agents 671 (11.1) Calcium channel blockers 648 (10.7) LMWH 114 (1.9) Gp IIb/IIIa receptor antagonist 113 (1.9) Bivalirudin or hirudin 7 (0.1) Medications in hospital after randomisation, No. (%) Fondaparinux (n = 6056) Aspirin 5841 (96.8) Beta-Blockers 5092 (84.4) ACE inhibitor or ARB 4795 (79.4) Clopidogrel or ticlopidine 3481 (57.7) UFH 651 (10.8) Lipid-lowering agents 4494 (74.5) Calcium channel blockers 639 (10.6) LMWH 322 (5.3) Gp IIb/IIIa receptor antagonist 951 (15.8) Bivalirudin or hirudin 5 (0.1) Placebo or UFH (n = 6036) Aspirin 5839 (96.4) Beta-Blockers 5074 (83.8) ACE inhibitor or ARB 4847 (80.0) Clopidogrel or ticlopidine 3540 (58.5) UFH 681 (11.2) Lipid-lowering agents 4529 (74.8) Calcium channel blockers 624 (10.3) LMWH 384 (6.3) Gp IIb/IIIa receptor antagonist 941 (15.5) Bivalirudin or hirudin 7 (0.1) ACE inhibitor or ARB Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, Gp IIb/IIIa receptor antagonist glycoprotein IIb/ IIIa receptor antagonist Outcomes Clinical efficacy: primary end point composite of death and re-infarction at 30 days, secondary endpoints death and re-infarction at nine days, three months and six months Safety outcome: severe bleeding, major bleeding. Notes OASIS 6 Follow up till to hospital discharge, 30, 90 and 180 days. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 36 Yusuf 2006 OASIS 6 (Continued) Analysis according to intention to treat Analyses of subgroup related to primary percutaneous coronary procedures The UFH group had 11 participants lost to follow up, the group fondaparinux had 11 participants lost to follow up This study was conducted independently by the Steering Committee and the Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Ontario. No direct compensation was received by these individuals. The study was jointly funded by Sanofi-Aventis, Organon, and GlaxoSmithKline Risk of bias Item Authors’ judgement Description Adequate sequence generation? Unclear Randomization was stratified by indication for the use of UFH based on the investigator´ s judgment. There is no detailed information about the sequence of generation process to permit its judgment Allocation concealment? Unclear Participants deemed ineligible for reperfusion therapy by the investigator criteria. Randomization was stratified by the indication for unfractionated heparin(stratum II) or not (stratum I) based on the investigator‘s judgment The method of concealment was not described in details to allow a definite judgment Blinding? All outcomes Yes Double blind - double dummy. Those patients with indication for UFH (enrolled as stratum 2) were assigned to receive either blinded fondaparinux or matching placebo, initial dose intravenous and subsequent doses subcutaneously. Those in the control group received a bolus injection of UFH followed by an infusion per 24 to 48 hours. Equivalent placebo bolus and injections were used in the fondaparinux group. To maintain the double blind criteria patients receiving UFH or placebo infusion have regular activated partial thromboplastin time monitoring using a “hemachron” device. A central computerized system produced either real or sham activated partial thromboplastin time values,which were used to adjust the rate of infusion Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 37 Yusuf 2006 OASIS 6 (Continued) Incomplete outcome data addressed? All outcomes Yes Vital status was ascertained in 6032 fondaparinux and 6428 UFH- placebo patients at 30 days Free of selective reporting? Yes The authors received research support or consultant fees from the pharmaceutical company related to the study drug, but there was insufficient rationale or evidence that this situation could have introduced bias Free of other bias? Yes No sources of bias were identified. Characteristics of excluded studies [ordered by study ID] Study Reason for exclusion Alexander 2005 Small phase II trial to determine a dose of DX-9065 with a favourable safety profile when given with standard non ST elevation ACS medical therapy; and to compare the effect of heparin vs DX-9065a on ischemic endpoints in patients with non-ST elevation ACS The direct factor Xa inhibitor, though promising DX 9065 has not undergone further clinical evaluation (ACCP 2008). Cohen 2007 The objective was to determine the optimal anticoagulant regimen for percutaneous coronary intervention (PCI) of otamixaban, a selective and direct inhibitor of factor Xa, investigated in patients undergoing non urgent PCI The primary end points were change in prothrombin fragments 1+2 (F1+2), and anti-factor Xa activity Mehta 2007 It was a randomised trial performed to determine the safety and feasibility of fondaparinux in the percutaneous coronary intervention (PCI) setting, so it included patients who were allocated to urgent percutaneous coronary proceedings or elective ones because of ACS or stable angina respectively Vuillemenot 1999 It was a Phase IIa, open label, non-controlled, pilot study assessing a 12 mg iv bolus of SR90107/ORG31540. (Fondaparinux), including patients with a history of stable angina, > 7-day unstable angina or MI and a 70% stenosis in an epicardial vessel selected for conventional balloon. The aim of the study was to test the antithrombotic properties of SR90107/ORG31540 (fondaparinux) during percutaneous transluminal coronary angioplasty (PTCA), a procedure known to be associated with an increased risk of arterial thrombosis, abrupt coronary vessel closure during or within 24 h. after Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 38 Characteristics of studies awaiting assessment [ordered by study ID] Oasis 8 Methods Phase IV study, Interventional, Randomised, Double blind The purpose of this study is to compare the safety of two different dose regimens of unfractionated heparin (UFH) during a PCI procedure in patients with UA (unstable angina)/NSTEMI (non ST segment elevation myocardial infarction) who have been initially treated with fondaparinux Subjects presenting at hospital with suspected UA or NSTEMI and who are likely to undergo angiography (ideally within 72 hours) will be assessed for eligibility and consented. Suitable subjects will be enrolled and commence treatment with open-label fondaparinux, 2.5 mg, subcutaneous (s. c)., once daily. Following angiography subjects indicated for PCI and meeting the additional requirements for randomisation will be randomised to receive one of two dose regimens of UFH either standard dose or low dose immediately prior to the PCI procedure. Post-PCI, therapy with fondaparinux (2.5 mg, s.c.) may be resumed at the investigator’s discretion for up to a maximum of eight days or hospital discharge, whichever is earlier Subjects not indicated for PCI, will continue treatment with fondaparinux, 2.5mg, s.c, once daily for up to 8 days or hospital discharge, whichever is earlier All subjects will be followed up for 30 days after randomisation/angiography Participants Estimated 4000. Both genders. 21 y.o or older. Interventions Standard dose UFH: Experimental No planned GPIIb/IIIa use: 85 U/kg bolus with additional bolus (2,000 U - 4, 000U) if needed to achieve a target ACT of 300 - 350 seconds (using the HEMOCHRON device) or ACT of 250 300 seconds (using the HEMOTECH device). Planned GPIIb/IIIa use: 60 U/kg bolus with additional bolus of (2, 000 U - 4,000U) if needed to achieve target ACT of ?200 seconds (using the HEMOCHRON or HEMOTECH device) • Intervention: Drug: Unfractioned heparin Fondaparinux treated patients, eligible for PCI, will be randomised to receive one of two doses of unfractionated heparin (UFH) at least 1 minute prior to insertion of the guidewire Low Dose UFH: Experimental - All subjects irrespective of planned GPIIb/IIIa use: 50 U/kg bolus • Intervention: Drug: Unfractioned heparin Fondaparinux treated patients, eligible for PCI, will be randomised to receive one of two doses of unfractionated heparin (UFH) at least one minute prior to insertion of the guidewire. Outcomes Standard dose UFH: Experimental • No planned GPIIb/IIIa use: 85 U/kg bolus with additional bolus (2,000 U - 4,000U) if needed to achieve a target ACT of 300 - 350 seconds (using the HEMOCHRON device) or ACT of 250 - 300 seconds (using the HEMOTECH device). • Planned GPIIb/IIIa use: 60 U/kg bolus with additional bolus of (2,000 U - 4,000U) if needed to achieve target ACT of ?200 seconds (using the HEMOCHRON or HEMOTECH device) Notes ClinicalTrials.gov identifier: NCT00790907 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 39 Sabatine 2009 Methods Phase II double blind randomised controlled trial Study aim: To assess efficacy and safety in non-ST elevation acute coronary syndromes of Otamixaban, intravenous direct factor Xa inhibitor, compared to UFH. To identify its optimum dose range for future assessment in a phase 3 study Participants 3241 in 196 sites in 36 countries Interventions Patients were randomly assigned via a central, telephone- based interactive voice response system, to one of five doses of otamixaban or to a control of UFH Outcomes Primary efficacy endpoint was a composite of death, myocardial infarction, urgent revascularization, or bailout glycoprotein IIb- IIIa inhibitor use up to seven days by intention to treat Primary safety endpoint was TIMI major or minor bleeding not related to coronary -artery bypass grafting in treated patients Notes NCT00317395 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 40 DATA AND ANALYSES Comparison 1. Fondaparinuxs vs. anticoagulants Outcome or subgroup title 1 All-cause mortality at 30 days 1.1 UFH 1.2 Enoxaparin 2 All-cause mortality at 90 to 180 days 2.1 UFH 2.2 Enoxaparin 3 Non-fatal AMI or re-infarction at 9 days 3.1 UFH 3.2 Enoxaparin 4 Non-fatal AMI or re-infarction at 30 days 4.1 UFH 4.2 Enoxaparin 5 Combined endpoint of all-cause mortality, non-fatal AMI or re-infarction at 9 days 5.1 UFH 5.2 Enoxaparin 6 Major bleeding at 9 days 6.1 UFH 6.2 Enoxaparin 7 Major bleeding at 30 days 7.1 UFH 7.2 Enoxaparin 8 Minor bleeding at 30 days 8.1 UFH 8.2 Enoxaparin No. of studies No. of participants 4 2 2 2 27976 6760 21216 26512 Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) 0.90 [0.80, 1.01] 0.98 [0.82, 1.18] 0.85 [0.73, 0.98] 0.89 [0.81, 0.97] 1 1 3 6434 20078 27650 Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Random, 95% CI) 0.88 [0.75, 1.03] 0.90 [0.80, 1.00] 0.89 [0.68, 1.17] 1 2 3 6434 21216 26838 Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) 0.69 [0.47, 1.01] 1.00 [0.84, 1.18] 0.92 [0.81, 1.04] 2 1 3 6760 20078 27650 Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) 0.84 [0.62, 1.15] 0.94 [0.82, 1.07] 0.97 [0.87, 1.08] 1 2 3 1 2 2 1 1 2 1 1 6434 21216 27650 6434 21216 20404 326 20078 20404 326 20078 Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) 0.92 [0.77, 1.11] 1.00 [0.87, 1.14] 0.74 [0.42, 1.31] 0.93 [0.67, 1.29] 0.92 [0.15, 5.66] 0.79 [0.39, 1.59] 1.41 [0.49, 4.10] 0.63 [0.55, 0.73] 0.70 [0.14, 3.39] 1.76 [0.52, 5.94] 0.34 [0.28, 0.43] Statistical method Effect size Comparison 2. Low dose fondaparinux vs. anticoagulants Outcome or subgroup title 1 All-cause mortality at 30 days 1.1 UFH 1.2 Enoxaparin 2 Non-fatal AMI or re-infarction at 30 days No. of studies No. of participants 4 2 2 3 27357 6600 20757 26678 Statistical method Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Effect size 0.92 [0.75, 1.12] 0.98 [0.82, 1.17] 1.53 [0.29, 8.25] 0.90 [0.65, 1.23] 41 2.1 UFH 2.2 Enoxaparin 3 Major bleeding at 9 days 3.1 UFH 3.2 Enoxaparin 2 1 4 2 2 6600 20078 27357 6600 20757 Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) 0.85 [0.40, 1.83] 0.99 [0.84, 1.17] 0.75 [0.45, 1.26] 0.94 [0.68, 1.29] 0.76 [0.17, 3.38] Comparison 3. Fondaparinux vs. anticoagulants in PCI Outcome or subgroup title 1 All-cause mortality at 30 days 1.1 UFH 1.2 Enoxaparin 2 Non-fatal AMI or re-infarction at 30 days 2.1 UFH 2.2 Enoxaparin 3 Major bleeding at 9 days 3.1 UFH 3.2 Enoxaparin 4 Catheter thrombosis 4.1 UFH 4.2 Enoxaparin No. of studies No. of participants 2 1 1 2 9945 3768 6177 9945 Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) 1.05 [0.83, 1.32] 1.14 [0.84, 1.55] 0.94 [0.67, 1.33] 1.08 [0.89, 1.30] 1 1 2 1 1 2 1 1 3768 6177 9945 3768 6177 10006 3768 6238 Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) 1.23 [0.76, 2.00] 1.05 [0.86, 1.29] 0.76 [0.28, 2.05] 1.28 [0.81, 2.04] 0.47 [0.35, 0.61] 9.42 [0.64, 139.63] 44.71 [2.71, 736.57] 3.59 [1.64, 7.84] Statistical method Effect size Comparison 4. Sensitivity analyses Outcome or subgroup title 1 All-cause mortality at 30 days 1.1 UFH 1.2 Enoxaparin 2 Major bleeding at 9 days 2.1 UFH 2.2 Enoxaparin No. of studies No. of participants 2 1 1 2 1 1 26512 6434 20078 26512 6434 20078 Statistical method Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Fixed, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Risk Ratio (M-H, Random, 95% CI) Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Effect size 0.89 [0.79, 1.00] 0.98 [0.81, 1.17] 0.84 [0.72, 0.97] 0.69 [0.39, 1.21] 0.93 [0.67, 1.29] 0.53 [0.45, 0.62] 42 Analysis 1.1. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 1 All-cause mortality at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 1 All-cause mortality at 30 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 6/241 1/85 0.3 % 2.12 [ 0.26, 17.32 ] 213/3213 219/3221 37.9 % 0.98 [ 0.81, 1.17 ] 3454 3306 38.1 % 0.98 [ 0.82, 1.18 ] 19/908 3/230 0.8 % 1.60 [ 0.48, 5.37 ] 295/10057 352/10021 61.0 % 0.84 [ 0.72, 0.97 ] 10965 10251 61.9 % 0.85 [ 0.73, 0.98 ] 13557 100.0 % 0.90 [ 0.80, 1.01 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Coussement 2001 Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 219 (Fondaparinux), 220 (Anticoagulants) Heterogeneity: Chi2 = 0.52, df = 1 (P = 0.47); I2 =0.0% Test for overall effect: Z = 0.19 (P = 0.85) 2 Enoxaparin Simoons 2004 Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 314 (Fondaparinux), 355 (Anticoagulants) Heterogeneity: Chi2 = 1.10, df = 1 (P = 0.29); I2 =9% Test for overall effect: Z = 2.18 (P = 0.029) Total (95% CI) 14419 Total events: 533 (Fondaparinux), 575 (Anticoagulants) Heterogeneity: Chi2 = 3.18, df = 3 (P = 0.36); I2 =6% Test for overall effect: Z = 1.82 (P = 0.068) 0.05 0.2 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 5 20 Favours anticoagulants 43 Analysis 1.2. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 2 All-cause mortality at 90 to 180 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 2 All-cause mortality at 90 to 180 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 262/3213 299/3221 31.8 % 0.88 [ 0.75, 1.03 ] 3213 3221 31.8 % 0.88 [ 0.75, 1.03 ] 574/10057 638/10021 68.2 % 0.90 [ 0.80, 1.00 ] 10057 10021 68.2 % 0.90 [ 0.80, 1.00 ] 13242 100.0 % 0.89 [ 0.81, 0.97 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 262 (Fondaparinux), 299 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 1.60 (P = 0.11) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 574 (Fondaparinux), 638 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 1.96 (P = 0.050) Total (95% CI) 13270 Total events: 836 (Fondaparinux), 937 (Anticoagulants) Heterogeneity: Chi2 = 0.04, df = 1 (P = 0.84); I2 =0.0% Test for overall effect: Z = 2.52 (P = 0.012) 0.5 0.7 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 1.5 2 Favours anticoagulants 44 Analysis 1.3. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 3 Non-fatal AMI or re-infarction at 9 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 3 Non-fatal AMI or re-infarction at 9 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 44/3213 64/3221 31.6 % 0.69 [ 0.47, 1.01 ] 3213 3221 31.6 % 0.69 [ 0.47, 1.01 ] 263/10057 264/10021 63.9 % 0.99 [ 0.84, 1.17 ] 14/908 3/230 4.5 % 1.18 [ 0.34, 4.08 ] 10965 10251 68.4 % 1.00 [ 0.84, 1.18 ] 100.0 % 0.89 [ 0.68, 1.17 ] 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 44 (Fondaparinux), 64 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 1.92 (P = 0.055) 2 Enoxaparin Yusuf 2006 OASIS 5 Simoons 2004 Subtotal (95% CI) Total events: 277 (Fondaparinux), 267 (Anticoagulants) Heterogeneity: Tau2 = 0.0; Chi2 = 0.08, df = 1 (P = 0.78); I2 =0.0% Test for overall effect: Z = 0.05 (P = 0.96) Total (95% CI) 14178 13472 Total events: 321 (Fondaparinux), 331 (Anticoagulants) Heterogeneity: Tau2 = 0.02; Chi2 = 3.09, df = 2 (P = 0.21); I2 =35% Test for overall effect: Z = 0.83 (P = 0.40) 0.1 0.2 0.5 Favours fondaparinux 1 2 5 10 Favours anticoagulants Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 45 Analysis 1.4. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 4 Non-fatal AMI or re-infarction at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 4 Non-fatal AMI or re-infarction at 30 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 9/241 3/85 0.9 % 1.06 [ 0.29, 3.82 ] 69/3213 83/3221 16.6 % 0.83 [ 0.61, 1.14 ] 3454 3306 17.5 % 0.84 [ 0.62, 1.15 ] 387/10057 411/10021 82.5 % 0.94 [ 0.82, 1.07 ] 10057 10021 82.5 % 0.94 [ 0.82, 1.07 ] 13327 100.0 % 0.92 [ 0.81, 1.04 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Coussement 2001 Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 78 (Fondaparinux), 86 (Anticoagulants) Heterogeneity: Chi2 = 0.13, df = 1 (P = 0.72); I2 =0.0% Test for overall effect: Z = 1.08 (P = 0.28) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 387 (Fondaparinux), 411 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.92 (P = 0.36) Total (95% CI) 13511 Total events: 465 (Fondaparinux), 497 (Anticoagulants) Heterogeneity: Chi2 = 0.50, df = 2 (P = 0.78); I2 =0.0% Test for overall effect: Z = 1.28 (P = 0.20) 0.1 0.2 0.5 Favours fondaparinux 1 2 5 10 Favours anticoagulants Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 46 Analysis 1.5. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 5 Combined endpoint of all-cause mortality, non-fatal AMI or re-infarction at 9 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 5 Combined endpoint of all-cause mortality, non-fatal AMI or re-infarction at 9 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 205/3213 223/3221 34.7 % 0.92 [ 0.77, 1.11 ] 3213 3221 34.7 % 0.92 [ 0.77, 1.11 ] 25/908 4/230 1.0 % 1.58 [ 0.56, 4.50 ] 409/10057 412/10021 64.3 % 0.99 [ 0.87, 1.13 ] 10965 10251 65.3 % 1.00 [ 0.87, 1.14 ] 13472 100.0 % 0.97 [ 0.87, 1.08 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 205 (Fondaparinux), 223 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.87 (P = 0.38) 2 Enoxaparin Simoons 2004 Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 434 (Fondaparinux), 416 (Anticoagulants) Heterogeneity: Chi2 = 0.77, df = 1 (P = 0.38); I2 =0.0% Test for overall effect: Z = 0.03 (P = 0.98) Total (95% CI) 14178 Total events: 639 (Fondaparinux), 639 (Anticoagulants) Heterogeneity: Chi2 = 1.23, df = 2 (P = 0.54); I2 =0.0% Test for overall effect: Z = 0.52 (P = 0.60) 0.02 0.1 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 10 50 Favours anticoagulants 47 Analysis 1.6. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 6 Major bleeding at 9 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 6 Major bleeding at 9 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 68/3213 73/3221 45.3 % 0.93 [ 0.67, 1.29 ] 3213 3221 45.3 % 0.93 [ 0.67, 1.29 ] 8/908 0/230 3.7 % 4.32 [ 0.25, 74.57 ] 217/10057 411/10021 51.0 % 0.53 [ 0.45, 0.62 ] 10965 10251 54.7 % 0.92 [ 0.15, 5.66 ] 100.0 % 0.74 [ 0.42, 1.31 ] 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 68 (Fondaparinux), 73 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.41 (P = 0.68) 2 Enoxaparin Simoons 2004 Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 225 (Fondaparinux), 411 (Anticoagulants) Heterogeneity: Tau2 = 1.16; Chi2 = 2.10, df = 1 (P = 0.15); I2 =52% Test for overall effect: Z = 0.09 (P = 0.92) Total (95% CI) 14178 13472 Total events: 293 (Fondaparinux), 484 (Anticoagulants) Heterogeneity: Tau2 = 0.16; Chi2 = 11.38, df = 2 (P = 0.003); I2 =82% Test for overall effect: Z = 1.04 (P = 0.30) 0.01 0.1 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 10 100 Favours anticoagulants 48 Analysis 1.7. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 7 Major bleeding at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 7 Major bleeding at 30 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 16/241 4/85 27.5 % 1.41 [ 0.49, 4.10 ] 241 85 27.5 % 1.41 [ 0.49, 4.10 ] 313/10057 494/10021 72.5 % 0.63 [ 0.55, 0.73 ] 10057 10021 72.5 % 0.63 [ 0.55, 0.73 ] 10106 100.0 % 0.79 [ 0.39, 1.59 ] 1 UFH Coussement 2001 Subtotal (95% CI) Total events: 16 (Fondaparinux), 4 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.63 (P = 0.53) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 313 (Fondaparinux), 494 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 6.49 (P < 0.00001) Total (95% CI) 10298 Total events: 329 (Fondaparinux), 498 (Anticoagulants) Heterogeneity: Tau2 = 0.17; Chi2 = 2.14, df = 1 (P = 0.14); I2 =53% Test for overall effect: Z = 0.67 (P = 0.51) 0.05 0.2 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 5 20 Favours anticoagulants 49 Analysis 1.8. Comparison 1 Fondaparinuxs vs. anticoagulants, Outcome 8 Minor bleeding at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 1 Fondaparinuxs vs. anticoagulants Outcome: 8 Minor bleeding at 30 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 15/241 3/85 43.0 % 1.76 [ 0.52, 5.94 ] 241 85 43.0 % 1.76 [ 0.52, 5.94 ] 111/10057 321/10021 57.0 % 0.34 [ 0.28, 0.43 ] 10057 10021 57.0 % 0.34 [ 0.28, 0.43 ] 10106 100.0 % 0.70 [ 0.14, 3.39 ] 1 UFH Coussement 2001 Subtotal (95% CI) Total events: 15 (Fondaparinux), 3 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.92 (P = 0.36) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 111 (Fondaparinux), 321 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 9.76 (P < 0.00001) Total (95% CI) 10298 Total events: 126 (Fondaparinux), 324 (Anticoagulants) Heterogeneity: Tau2 = 1.14; Chi2 = 6.73, df = 1 (P = 0.01); I2 =85% Test for overall effect: Z = 0.45 (P = 0.65) 0.01 0.1 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 10 100 Favours anticoagulants 50 Analysis 2.1. Comparison 2 Low dose fondaparinux vs. anticoagulants, Outcome 1 All-cause mortality at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 2 Low dose fondaparinux vs. anticoagulants Outcome: 1 All-cause mortality at 30 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 213/3213 219/3221 46.2 % 0.98 [ 0.81, 1.17 ] 2/81 1/85 0.7 % 2.10 [ 0.19, 22.70 ] 3294 3306 46.9 % 0.98 [ 0.82, 1.17 ] 1 UFH Yusuf 2006 OASIS 6 Coussement 2001 Subtotal (95% CI) Total events: 215 (Fondaparinux), 220 (Anticoagulants) Heterogeneity: Tau2 = 0.0; Chi2 = 0.40, df = 1 (P = 0.53); I2 =0.0% Test for overall effect: Z = 0.22 (P = 0.82) 2 Enoxaparin Yusuf 2006 OASIS 5 Simoons 2004 Subtotal (95% CI) 295/10057 352/10021 52.2 % 0.84 [ 0.72, 0.97 ] 10/449 1/230 0.9 % 5.12 [ 0.66, 39.77 ] 10506 10251 53.1 % 1.53 [ 0.29, 8.25 ] 100.0 % 0.92 [ 0.75, 1.12 ] Total events: 305 (Fondaparinux), 353 (Anticoagulants) Heterogeneity: Tau2 = 1.10; Chi2 = 3.01, df = 1 (P = 0.08); I2 =67% Test for overall effect: Z = 0.50 (P = 0.62) Total (95% CI) 13800 13557 Total events: 520 (Fondaparinux), 573 (Anticoagulants) Heterogeneity: Tau2 = 0.01; Chi2 = 4.92, df = 3 (P = 0.18); I2 =39% Test for overall effect: Z = 0.84 (P = 0.40) 0.05 0.2 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 5 20 Favours anticoagulants 51 Analysis 2.2. Comparison 2 Low dose fondaparinux vs. anticoagulants, Outcome 2 Non-fatal AMI or reinfarction at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 2 Low dose fondaparinux vs. anticoagulants Outcome: 2 Non-fatal AMI or re-infarction at 30 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 5/81 3/85 4.8 % 1.75 [ 0.43, 7.08 ] 44/3213 64/3221 35.3 % 0.69 [ 0.47, 1.01 ] 3294 3306 40.0 % 0.85 [ 0.40, 1.83 ] 1 UFH Coussement 2001 Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 49 (Fondaparinux), 67 (Anticoagulants) Heterogeneity: Tau2 = 0.16; Chi2 = 1.59, df = 1 (P = 0.21); I2 =37% Test for overall effect: Z = 0.41 (P = 0.68) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) 263/10057 264/10021 60.0 % 0.99 [ 0.84, 1.17 ] 10057 10021 60.0 % 0.99 [ 0.84, 1.17 ] 13327 100.0 % 0.90 [ 0.65, 1.23 ] Total events: 263 (Fondaparinux), 264 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.09 (P = 0.93) Total (95% CI) 13351 Total events: 312 (Fondaparinux), 331 (Anticoagulants) Heterogeneity: Tau2 = 0.04; Chi2 = 3.71, df = 2 (P = 0.16); I2 =46% Test for overall effect: Z = 0.68 (P = 0.50) 0.2 0.5 Favours fondaparinux 1 2 5 Favours anticoagulants Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 52 Analysis 2.3. Comparison 2 Low dose fondaparinux vs. anticoagulants, Outcome 3 Major bleeding at 9 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 2 Low dose fondaparinux vs. anticoagulants Outcome: 3 Major bleeding at 9 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 4/81 4/85 11.0 % 1.05 [ 0.27, 4.06 ] 68/3213 73/3221 40.2 % 0.93 [ 0.67, 1.29 ] 3294 3306 51.2 % 0.94 [ 0.68, 1.29 ] 1 UFH Coussement 2001 Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 72 (Fondaparinux), 77 (Anticoagulants) Heterogeneity: Tau2 = 0.0; Chi2 = 0.03, df = 1 (P = 0.87); I2 =0.0% Test for overall effect: Z = 0.38 (P = 0.70) 2 Enoxaparin Simoons 2004 Yusuf 2006 OASIS 5 Subtotal (95% CI) 3/449 0/230 2.8 % 3.59 [ 0.19, 69.27 ] 217/10057 412/10021 46.0 % 0.52 [ 0.45, 0.62 ] 10506 10251 48.8 % 0.76 [ 0.17, 3.38 ] 100.0 % 0.75 [ 0.45, 1.26 ] Total events: 220 (Fondaparinux), 412 (Anticoagulants) Heterogeneity: Tau2 = 0.71; Chi2 = 1.62, df = 1 (P = 0.20); I2 =38% Test for overall effect: Z = 0.36 (P = 0.72) Total (95% CI) 13800 13557 Total events: 292 (Fondaparinux), 489 (Anticoagulants) Heterogeneity: Tau2 = 0.14; Chi2 = 11.71, df = 3 (P = 0.01); I2 =74% Test for overall effect: Z = 1.09 (P = 0.28) 0.02 0.1 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 10 50 Favours anticoagulants 53 Analysis 3.1. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 1 All-cause mortality at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 3 Fondaparinux vs. anticoagulants in PCI Outcome: 1 All-cause mortality at 30 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 85/1890 74/1878 53.2 % 1.14 [ 0.84, 1.55 ] 1890 1878 53.2 % 1.14 [ 0.84, 1.55 ] 62/3105 65/3072 46.8 % 0.94 [ 0.67, 1.33 ] 3105 3072 46.8 % 0.94 [ 0.67, 1.33 ] 4950 100.0 % 1.05 [ 0.83, 1.32 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 85 (Fondaparinux), 74 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.85 (P = 0.40) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 62 (Fondaparinux), 65 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.33 (P = 0.74) Total (95% CI) 4995 Total events: 147 (Fondaparinux), 139 (Anticoagulants) Heterogeneity: Chi2 = 0.66, df = 1 (P = 0.42); I2 =0.0% Test for overall effect: Z = 0.41 (P = 0.68) 0.05 0.2 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 5 20 Favours anticoagulants 54 Analysis 3.2. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 2 Non-fatal AMI or reinfarction at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 3 Fondaparinux vs. anticoagulants in PCI Outcome: 2 Non-fatal AMI or re-infarction at 30 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 36/1890 29/1878 14.7 % 1.23 [ 0.76, 2.00 ] 1890 1878 14.7 % 1.23 [ 0.76, 2.00 ] 179/3105 168/3072 85.3 % 1.05 [ 0.86, 1.29 ] 3105 3072 85.3 % 1.05 [ 0.86, 1.29 ] 4950 100.0 % 1.08 [ 0.89, 1.30 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 36 (Fondaparinux), 29 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.85 (P = 0.40) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 179 (Fondaparinux), 168 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.51 (P = 0.61) Total (95% CI) 4995 Total events: 215 (Fondaparinux), 197 (Anticoagulants) Heterogeneity: Chi2 = 0.34, df = 1 (P = 0.56); I2 =0.0% Test for overall effect: Z = 0.81 (P = 0.42) 0.5 0.7 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 1.5 2 Favours anticoagulants 55 Analysis 3.3. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 3 Major bleeding at 9 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 3 Fondaparinux vs. anticoagulants in PCI Outcome: 3 Major bleeding at 9 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 40/1890 31/1878 48.2 % 1.28 [ 0.81, 2.04 ] 1890 1878 48.2 % 1.28 [ 0.81, 2.04 ] 73/3105 155/3072 51.8 % 0.47 [ 0.35, 0.61 ] 3105 3072 51.8 % 0.47 [ 0.35, 0.61 ] 4950 100.0 % 0.76 [ 0.28, 2.05 ] 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 40 (Fondaparinux), 31 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 1.05 (P = 0.29) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 73 (Fondaparinux), 155 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 5.47 (P < 0.00001) Total (95% CI) 4995 Total events: 113 (Fondaparinux), 186 (Anticoagulants) Heterogeneity: Tau2 = 0.47; Chi2 = 13.54, df = 1 (P = 0.00023); I2 =93% Test for overall effect: Z = 0.55 (P = 0.59) 0.01 0.1 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 10 100 Favours anticoagulants 56 Analysis 3.4. Comparison 3 Fondaparinux vs. anticoagulants in PCI, Outcome 4 Catheter thrombosis. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 3 Fondaparinux vs. anticoagulants in PCI Outcome: 4 Catheter thrombosis Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 22/1890 0/1878 38.2 % 44.71 [ 2.71, 736.57 ] 1890 1878 38.2 % 44.71 [ 2.71, 736.57 ] 29/3134 8/3104 61.8 % 3.59 [ 1.64, 7.84 ] 3134 3104 61.8 % 3.59 [ 1.64, 7.84 ] 4982 100.0 % 9.42 [ 0.64, 139.63 ] 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 22 (Fondaparinux), 0 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 2.66 (P = 0.0078) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 29 (Fondaparinux), 8 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 3.21 (P = 0.0013) Total (95% CI) 5024 Total events: 51 (Fondaparinux), 8 (Anticoagulants) Heterogeneity: Tau2 = 2.91; Chi2 = 3.64, df = 1 (P = 0.06); I2 =73% Test for overall effect: Z = 1.63 (P = 0.10) 0.001 0.01 0.1 Favours fondaparinux 1 10 100 1000 Favours anticoagulants Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 57 Analysis 4.1. Comparison 4 Sensitivity analyses, Outcome 1 All-cause mortality at 30 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 4 Sensitivity analyses Outcome: 1 All-cause mortality at 30 days Study or subgroup Fondaparinux Anticoagulants n/N n/N Risk Ratio Weight 213/3213 219/3221 38.3 % 0.98 [ 0.81, 1.17 ] 3213 3221 38.3 % 0.98 [ 0.81, 1.17 ] 295/10057 352/10021 61.7 % 0.84 [ 0.72, 0.97 ] 10057 10021 61.7 % 0.84 [ 0.72, 0.97 ] 13242 100.0 % 0.89 [ 0.79, 1.00 ] M-H,Fixed,95% CI Risk Ratio M-H,Fixed,95% CI 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 213 (Fondaparinux), 219 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.27 (P = 0.79) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 295 (Fondaparinux), 352 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 2.32 (P = 0.020) Total (95% CI) 13270 Total events: 508 (Fondaparinux), 571 (Anticoagulants) Heterogeneity: Chi2 = 1.64, df = 1 (P = 0.20); I2 =39% Test for overall effect: Z = 1.98 (P = 0.047) 0.05 0.2 1 Favours fondaparinux Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 5 20 Favours anticoagulants 58 Analysis 4.2. Comparison 4 Sensitivity analyses, Outcome 2 Major bleeding at 9 days. Review: Factor Xa inhibitors for acute coronary syndromes Comparison: 4 Sensitivity analyses Outcome: 2 Major bleeding at 9 days Study or subgroup Fondaparinux Anticoagulants Risk Ratio MH,Random,95% CI Weight Risk Ratio MH,Random,95% CI n/N n/N 68/3213 73/3221 46.8 % 0.93 [ 0.67, 1.29 ] 3213 3221 46.8 % 0.93 [ 0.67, 1.29 ] 217/10057 411/10021 53.2 % 0.53 [ 0.45, 0.62 ] 10057 10021 53.2 % 0.53 [ 0.45, 0.62 ] 13242 100.0 % 0.69 [ 0.39, 1.21 ] 1 UFH Yusuf 2006 OASIS 6 Subtotal (95% CI) Total events: 68 (Fondaparinux), 73 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 0.41 (P = 0.68) 2 Enoxaparin Yusuf 2006 OASIS 5 Subtotal (95% CI) Total events: 217 (Fondaparinux), 411 (Anticoagulants) Heterogeneity: not applicable Test for overall effect: Z = 7.76 (P < 0.00001) Total (95% CI) 13270 Total events: 285 (Fondaparinux), 484 (Anticoagulants) Heterogeneity: Tau2 = 0.15; Chi2 = 9.51, df = 1 (P = 0.002); I2 =89% Test for overall effect: Z = 1.30 (P = 0.19) 0.01 0.1 1 Favours fondaparinux 10 100 Favours anticoagulants ADDITIONAL TABLES Table 1. QUALITY ASSESSMENT CRITERIA ASSESMENT A ALLOCATION CONCEAL- ADEQUATE MENT B NOT UNCLEAR C REPORTED/ INADEQUATE TREATMENT BLINDING STATEMENT FINAL CON- NOT TAINERS WERE IDENTI- UNCLEAR CAL OUTCOME ASSESSMENT BLINDED, STANDARSED ASSESSMENT ASSESSASSESSMENT PROCEDURES NOT STAN- MENT NOT BLINDED OR DARISED NOT STANDARIZED Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. REPORTED/ STUDY / CONTROL DRUG NOT IDENTCIAL 59 Table 1. QUALITY ASSESSMENT CRITERIA (Continued) BASELINE EQUALITY GROUP BALANCED TERMS OF AGE, ETC IN BALANCE REPORTED LOSSES TO FOLLOW UP LOSSES OF 10% NOT UNCLEAR BASIS FOR ANALYSIS INTENTION TO TREAT UNCLEAR NOT GROUPS NOT BALANCED REPORTED/ LOSSES OF MORE THAN 10% NON- INTENTION TREAT TO APPENDICES Appendix 1. Search strategies CENTRAL # MeSH descriptor Myocardial Ischemia explode all trees # 2 angina # 3 myocardial next infarct* # 4 heart next infarct* # 5 acute next coronary # 6 coronary next syndrome* # 7 Preinfarction # 8 STEMI # 9 NONSTEMI # 10 NON-STEMI # 11 NSTEMI # 12 ACS # 13 (#1 or #2 or #3 or #4 or #5 or #6 or #7 or #8 or #9 or #10 or #11 or #12) # 14 fondaparinux # 15 idraparinux # 16 Arixtra # 17 otamixaban # 18 (xa near/6 inhibit*) # 19 (10a near/6 inhibit*) # 20 (xa near/6 antagonist*) # 21 (10a near/6 antagonist*) # 22 (xa near/6 block*) # 23 (“factor x” near/ 6 inhibit*) # 24 Fxa next inhibitor* # 25 vaso flux # 26 Razaxaban # 27 Fondaparin # 28 “Dx 9065*” # 29 (#14 or #15 or #16 or #17 or #18 or #19 or #20 or #21) Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 60 # 30 (#22 or #23 or #24 or #25 or #26 or #27 or #28) # 31 (#29 or #30) # 32 (#13 and #31) PubMed (Myocardial Ischemia[Mesh] OR Myocardial Ischemi*[tw] OR heart muscle ischemi*[tw] OR angina*[tw] OR myocardial infarct*[tw] OR heart infarct*[tw] OR acute coronar*[tw] OR coronary syndrome*[tw] OR Preinfarct*[tw] OR Pre Infarct*[tw] OR STEMI[tw] OR NONSTEMI[tw] OR NON-STEMI[tw] OR NSTEMI[tw] OR ACS[tiab] OR Acute Coronary Syndrome[Mesh]) AND (Fondaparinux[nm] OR Fondaparinux[tw] OR Idraparinux[tw] OR Arixtra[tw] OR Otamixaban[tw] OR xa inhibit*[tw] OR 10a inhibit*[tw] OR xa antagonist*[tw] OR 10a antagonist*[tw] OR xa block*[tw] OR factor x inhibit*[tw] OR Fxa inhibit*[tw] OR vaso flux*[tw] OR Razaxaban[tw] OR Fondaparin[tw] OR Dx 9065*[tw]) AND (Randomized controlled trial[pt] OR controlled clinical trial[pt] OR Randomized controlled trials[Mesh] OR Random allocation[Mesh] OR Double-blind method[Mesh] OR Single-blind method[Mesh] OR clinical trial[pt] OR Clinical trials[Mesh] OR (“clinical trial”[tw]) OR ((singl*[tw] OR doubl*[tw] OR trebl*[tw] OR tripl*[tw]) AND (mask*[tw] OR blind*[tw])) OR (Placebos[Mesh] OR placebo*[tw] OR random*[tw] OR Research design [mh: noexp]) NOT (Animals[Mesh] NOT Human[Mesh])) EMBASE 1 # exp heart muscle ischemia/ 2 # Myocardial Ischemi$.mp. 3 # angina.ti,ab. 4 # myocardial infarct$.mp. 5 # heart infarct$.mp. 6 # acute coronar$.mp. 7 # coronary syndrom$.mp. 8 # (Preinfarct$ or pre infarct$).mp. 9 # (STEMI or NONSTEMI or NON-STEMI or NSTEMI).mp. 10 # ACS.ti,ab. 11 # exp acute coronary syndrome/ 12 # or/1-11 13 # exp fondaparinux/ 14 # (fondaparinux or idraparinux or Arixtra or otamixaban or Razaxaban or Fonadaparin or Dx 9065$).mp. 15 # xa inhibit$.mp. 16 # 10a inhibit$.mp. 17 # xa antagonist$.mp. 18 # 10a antagonist$.mp. 19 # xa block$.mp. 20 # factor x inhibit$.mp. 21 # Fxa inhibit$.mp. 22 # vaso flux.mp. 23 # or/13-22 24 # 12 and 23 25 # (random$ or placebo$).ti,ab. 26 # (single$ or double$ or triple$ or treble$) and (blind$ or mask$)).ti,ab. 27# controlled clinical trial$.ti,ab. 28 # RETRACTED ARTICLE/ 29 # or/25-28 30 # (animal$ not human$).sh,hw. 31 # 29 not 30 32 # 24 and 31 Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 61 LILACS (MH Isquemia Miocárdica OR Myocardial Ischemi$ OR Isquemia Miocardi$ OR heart muscle ischemi$ OR angina$ OR myocardial infarct$ OR heart infarct$ OR Cardiopatia Isquemi$ OR isquemia cardi$ OR Doença Isquemi$ OR MH Síndrome Coronario Agudo OR Acute Coronar$ OR Síndrome Coronari$ OR Coronario Agudo$ OR Coronaria Agud$ OR Preinfarct$ OR Preinfart$ OR Pre Infart$ OR Pre infarct$ OR ST OR STEMI OR NONSTEMI OR NON-STEMI OR NSTEMI OR SCA OR ACS) AND (Fondaparinux or Idraparinux or Arixtra or Otamixaban OR xa inhibi$ OR xa inhibit$ OR xa inibi$ OR 10a inhibit$ OR 10a inhibi$ OR 10a inibi$ OR xa antagonist$ OR 10a antagonist$ OR xa block$ OR xa bloque$ OR factor X inhibit$ OR Inhibidor del factor X OR Inibidor do fator X OR Fxa inhibit$ OR Inhibidor del FX$ OR Inibidor do FX$ OR vaso flu$ OR Razaxaban OR Fonadaparin OR Dx 9065$) WHAT’S NEW Last assessed as up-to-date: 30 April 2009. Date Event Description 15 February 2011 Feedback has been incorporated Added a link to the Cochrane Editorial Unit’s report on feedback on anticoagulants reviews in the ’Published notes’ section HISTORY Protocol first published: Issue 2, 2008 Review first published: Issue 1, 2011 CONTRIBUTIONS OF AUTHORS Viviana Brito and Agustin Ciapponi: conception and design of study, analysis and interpretation of data. Viviana Brito, Agustin Ciapponi developed and executed the search strategies and drafted the review. Viviana Brito, Agustin Ciapponi and Joey Kwong revised the review and approved the final review version to be published. DECLARATIONS OF INTEREST None of the authors has any known conflict of interest. Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 62 SOURCES OF SUPPORT Internal sources • No form of support is provided to the authors of this review, Argentina. External sources • No form of support is provided to the authors of this review, Argentina. DIFFERENCES BETWEEN PROTOCOL AND REVIEW The angiographic efficacy of the agents on study compared to UFH or LMWH in patients suffering from ACS, was not reported since the available information to make an appropriate analyses was not enough. Similarly no reports could be done about their impact on revascularization at 30 days, length of hospitalisation, readmission after discharge, risk of adverse events such as thrombocytopenia or allergic reactions, as well as their effect on quality of life. Subgroups analyses to explore efficacy and safety in patients older than 75 years, in those on treatment with high doses of factor Xa inhibitors, or receiving other drugs which affect the coagulation cascade could not be analysed because not enough information was available. NOTES Feedback was received on the protocol for this review. This feedback, along with those on other reviews and protocols on anticoagulants, is available on the Cochrane Editorial Unit website at http://www.editorial-unit.cochrane.org/anticoagulants-feedback. INDEX TERMS Medical Subject Headings (MeSH) Acute Coronary Syndrome [∗ drug therapy]; Anticoagulants [∗ therapeutic use]; Coronary Thrombosis [prevention & control]; Factor Xa [∗ antagonists & inhibitors]; Heparin [therapeutic use]; Heparin, Low-Molecular-Weight [therapeutic use]; Polysaccharides [∗ therapeutic use]; Randomized Controlled Trials as Topic MeSH check words Humans Factor Xa inhibitors for acute coronary syndromes (Review) Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. 63
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