***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The combination of glycoprotein IIb/IIIa inhibitors and heparin has not been compared with bivalirudin in studies specifically involving patients with non-ST-segment elevation myocardial infa rct ion undergoing percutaneous coronary intervention ( PCI ) . We compared the two treatments in this patient population . METHODS Immediately before PCI , we r and omly assigned , in a double-blind manner , 1721 patients with acute non-ST-segment elevation myocardial infa rct ion to receive abciximab plus unfractionated heparin ( 861 patients ) or bivalirudin ( 860 patients ) . The study tested the hypothesis that abciximab and heparin would be superior to bivalirudin with respect to the primary composite end point of death , large recurrent myocardial infa rct ion , urgent target-vessel revascularization , or major bleeding within 30 days . Secondary end points included the composite of death , any recurrent myocardial infa rct ion , or urgent target-vessel revascularization ( efficacy end point ) and major bleeding ( safety end point ) within 30 days . RESULTS The primary end point occurred in 10.9 % of the patients in the abciximab group ( 94 patients ) and in 11.0 % in the bivalirudin group ( 95 patients ) ( relative risk with abciximab , 0.99 ; 95 % confidence interval [ CI ] , 0.74 to 1.32 ; P=0.94 ) . Death , any recurrent myocardial infa rct ion , or urgent target-vessel revascularization occurred in 12.8 % of the patients in the abciximab group ( 110 patients ) and in 13.4 % in the bivalirudin group ( 115 patients ) ( relative risk , 0.96 ; 95 % CI , 0.74 to 1.25 ; P=0.76 ) . Major bleeding occurred in 4.6 % of the patients in the abciximab group ( 40 patients ) as compared with 2.6 % in the bivalirudin group ( 22 patients ) ( relative risk , 1.84 ; 95 % CI , 1.10 to 3.07 ; P=0.02 ) . CONCLUSIONS Abciximab and unfractionated heparin , as compared with bivalirudin , failed to reduce the rate of the primary end point and increased the risk of bleeding among patients with non-ST-segment elevation myocardial infa rct ion who were undergoing PCI . ( Funded by Nycomed Pharma and others ; ISAR-REACT 4 Clinical Trials.gov number , NCT00373451 . ) CONTEXT Despite many therapeutic advances , mortality in patients with acute ST-segment elevation myocardial infa rct ion ( STEMI ) remains high . The role of additional antithrombotic agents is unclear , especially among patients not receiving reperfusion therapy . OBJECTIVE To evaluate the effect of fondaparinux , a factor Xa inhibitor , when initiated early and given for up to 8 days vs usual care ( placebo in those in whom unfractionated heparin [ UFH ] is not indicated [ stratum 1 ] or unfractionated heparin for up to 48 hours followed by placebo for up to 8 days [ stratum 2 ] ) in patients with STEMI . DESIGN , SETTING , AND PARTICIPANTS R and omized double-blind comparison of fondaparinux 2.5 mg once daily or control for up to 8 days in 12,092 patients with STEMI from 447 hospitals in 41 countries ( September 2003-January 2006 ) . From day 3 through day 9 , all patients received either fondaparinux or placebo according to the original r and omized assignment . MAIN OUTCOME MEASURES Composite of death or reinfa rct ion at 30 days ( primary ) with secondary assessment s at 9 days and at final follow-up ( 3 or 6 months ) . RESULTS Death or reinfa rct ion at 30 days was significantly reduced from 677 ( 11.2 % ) of 6056 patients in the control group to 585 ( 9.7 % ) of 6036 patients in the fondaparinux group ( hazard ratio [ HR ] , 0.86 ; 95 % confidence interval [ CI ] , 0.77 - 0.96 ; P = .008 ) ; absolute risk reduction , 1.5 % ; 95 % CI , 0.4%-2.6 % ) . These benefits were observed at 9 days ( 537 [ 8.9 % ] placebo vs 444 [ 7.4 % ] fondaparinux ; HR , 0.83 ; 95 % CI , 0.73 - 0.94 ; P = .003 , and at study end ( 857 [ 14.8 % ] placebo vs 756 [ 13.4 % ] fondaparinux ; HR , 0.88 ; 95 % CI , 0.79 - 0.97 ; P = .008 ) . Mortality was significantly reduced throughout the study . There was no heterogeneity of the effects of fondaparinux in the 2 strata by planned heparin use . However , there was no benefit in those undergoing primary percutaneous coronary intervention . In other patients in stratum 2 , fondaparinux was superior to unfractionated heparin in preventing death or reinfa rct ion at 30 days ( HR , 0.82 ; 95 % CI , 0.66 - 1.02 ; P = .08 ) and at study end ( HR , 0.77 ; 95 % CI , 0.64 - 0.93 ; P = .008 ) . Significant benefits were observed in those receiving thrombolytic therapy ( HR , 0.79 ; P = .003 ) and those not receiving any reperfusion therapy ( HR , 0.80 ; P = .03 ) . There was a tendency to fewer severe bleeds ( 79 for placebo vs 61 for fondaparinux ; P = .13 ) , with significantly fewer cardiac tamponade ( 48 vs 28 ; P = .02 ) with fondaparinux at 9 days . CONCLUSION In patients with STEMI , particularly those not undergoing primary percutaneous coronary intervention , fondaparinux significantly reduces mortality and reinfa rct ion without increasing bleeding and strokes . TRIAL REGISTRATION Clinical Trials.gov Identifier NCT00064428 BACKGROUND Conflicting evidence exists on the efficacy and safety of bivalirudin administered as part of percutaneous coronary intervention ( PCI ) in patients with an acute coronary syndrome . METHODS We r and omly assigned 7213 patients with an acute coronary syndrome for whom PCI was anticipated to receive either bivalirudin or unfractionated heparin .  Patients in the bivalirudin group were subsequently r and omly assigned to receive or not to receive a post-PCI bivalirudin infusion . Primary outcomes for the comparison between bivalirudin and heparin were the occurrence of major adverse cardiovascular events ( a composite of death , myocardial infa rct ion , or stroke ) and net adverse clinical events ( a composite of major bleeding or a major adverse cardiovascular event ) . The primary outcome for the comparison of a post-PCI bivalirudin infusion with no post-PCI infusion was a composite of urgent target-vessel revascularization , definite stent thrombosis , or net adverse clinical events . RESULTS The rate of major adverse cardiovascular events was not significantly lower with bivalirudin than with heparin ( 10.3 % and 10.9 % , respectively ; relative risk , 0.94 ; 95 % confidence interval [ CI ] , 0.81 to 1.09 ; P=0.44 ) , nor was the rate of net adverse clinical events ( 11.2 % and 12.4 % , respectively ; relative risk , 0.89 ; 95 % CI , 0.78 to 1.03 ; P=0.12 ) . Post-PCI bivalirudin infusion , as compared with no infusion , did not significantly decrease the rate of urgent target-vessel revascularization , definite stent thrombosis , or net adverse clinical events ( 11.0 % and 11.9 % , respectively ; relative risk , 0.91 ; 95 % CI , 0.74 to 1.11 ; P=0.34 ) . CONCLUSIONS In patients with an acute coronary syndrome , the rates of major adverse cardiovascular events and net adverse clinical events were not significantly lower with bivalirudin than with unfractionated heparin . The rate of the composite of urgent target-vessel revascularization , definite stent thrombosis , or net adverse clinical events was not significantly lower with a post-PCI bivalirudin infusion than with no post-PCI infusion . ( Funded by the Medicines Company and Terumo Medical ; MATRIX Clinical Trials.gov number , NCT01433627 . ) OBJECTIVES This study sought to assess the safety and the efficacy of bivalirudin compared with unfractionated heparin ( UFH ) alone in the subset of patients at increased risk of bleeding undergoing transfemoral elective percutaneous coronary intervention ( PCI ) . BACKGROUND Bivalirudin , a synthetic direct thrombin inhibitor , determines a significant decrease of in-hospital bleeding following PCI . METHODS This is a single-center , investigator-initiated , r and omized , double-blind , controlled trial . Consecutive biomarker-negative patients at increased bleeding risk undergoing PCI through the femoral approach were r and omized to UFH ( UFH group ; n = 419 ) or bivalirudin ( bivalirudin group ; n = 418 ) . The primary endpoint was the rate of in-hospital major bleeding . RESULTS The primary endpoint occurred in 11 patients ( 2.6 % ) in the UFH group versus 14 patients ( 3.3 % ) in the bivalirudin group ( odds ratio : 0.78 ; 95 % confidence interval : 0.35 to 1.72 ; p = 0.54 ) . Distribution of access-site and non-access-site bleeding was 18 % and 82 % in the UFH group versus 50 % and 50 % in the bivalirudin group ( p = 0.10 ) . CONCLUSIONS The results of this r and omized study , carried out at a single institution , suggest that there is no difference in major bleeding rate between bivalirudin and UFH in increased-risk patients undergoing transfemoral PCI . ( Novel Approaches in Preventing and Limiting Events III Trial : Bivalirudin in High-Risk Bleeding Patients [ NAPLES III ] ; NCT01465503 ) The r and omized TRial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet InhibitioN with Prasugrel-Thrombolysis In Myocardial Infa rct ion ( TRITON-TIMI ) 38 trial compared prasugrel and clopidogrel in patients with acute coronary syndrome undergoing percutaneous coronary intervention ( PCI ) . Patients treated with prasugrel had fewer ischemic events but more procedure-related bleeding . In the present study , we aim ed to determine the effect of bivalirudin on bleeding in patients treated with prasugrel .  A total of 692 patients with consecutive acute coronary syndrome underwent PCI with stent implantation and were anticoagulated with bivalirudin .  The patients were divided into 2 groups according to the antiplatelet regimen ( clopidogrel or prasugrel ) chosen during or just after PCI . The bleeding complications during hospitalization were tabulated . Ischemic events were analyzed during hospitalization and at 30 days . Prasugrel was used in 96 patients ( 13.9 % ) and clopidogrel in 596 ( 86.1 % ) . The clinical and procedural characteristics were similar , although the clopidogrel patients more often reported systemic hypertension ( p = 0.01 ) , previous PCI ( p < 0.001 ) , and chronic renal insufficiency ( p = 0.05 ) . During hospitalization , the bleeding and ischemic complication rates were similar and low in both groups ( major in-hospital complications 4.2 % for clopidogrel vs 2.1 % for prasugrel , p = 0.6 ; Thrombolysis In Myocardial Infa rct ion major bleeding 2.5 % vs 2.1 % , p = 1.00 ; Thrombolysis In Myocardial Infa rct ion minor bleeding 4.2 % vs 5.2 % , p = 0.6 ) . At 30 days , no differences were found in ischemic events between both groups ( target vessel revascularization/major adverse cardiac events 5.4 % vs 2.1 % , p = 0.2 ) . In conclusion , prasugrel , when given after bivalirudin as the intraprocedural antithrombin agent for patients with acute coronary syndrome undergoing PCI , is as safe and effective as clopidogrel BACKGROUND The combined use of anticoagulants , antiplatelet agents , and invasive coronary procedures reduces ischemic coronary events but also increases bleeding in patients with acute coronary syndromes . We therefore assessed whether fondaparinux would preserve the anti-ischemic benefits of enoxap 
    Output:
    
However , most trials showed decreased bleeding complications with bivalirudin , although ischemic complications and mortality were mostly comparable , with some favor towards bivalirudin .
Bivalirudin and heparin are both acceptable options according to current ACA/AHA guidelines .
Authors conclude however , that that due to bivalirudin safer bleeding profile , it should be the preferred medication for anticoagulation