***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 role of glycoprotein IIb/IIIa receptor antagonists for the treatment of patients with acute coronary syndrome and renal insufficiency remains undefined . Methods and Results — Patients from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms ( PRISM-PLUS ) trial were stratified by creatinine clearance ( CrCl ) and assessed with respect to treatment assignment to tirofiban/heparin versus heparin alone for the risk of adverse outcomes and bleeding . Patients with severe renal insufficiency ( defined as a serum creatinine ≥2.5 mg/dL ) were excluded from PRISM-PLUS as a whole . Patients with the lowest CrCl ( < 30 mL/min ) were more likely to present with high-risk clinical features . Decreasing renal function was strongly associated with adverse outcome , increasing the risk for ischemic complications at all time points examined ( all P < 0.002 ) . Irrespective of CrCl , therapy with tirofiban reduced the odds of the composite end point of death , myocardial infa rct ion , or refractory ischemia at 48 hours ( odds ratio [ OR ] , 0.68 ; 95 % confidence interval [ CI ] , 0.46 to 1.0;P = 0.05 ) , 7 days ( OR , 0.68 ; 95 % CI , 0.52 to 0.88;P = 0.003 ) , 30 days ( OR , 0.78 ; 95 % CI , 0.63 to 0.98;P = 0.03 ) , and 6 months ( OR , 0.81 ; 95 % CI , 0.68 to 0.98;P = 0.03 ) . The risk of myocardial infa rct ion/death was also significantly decreased to a similar magnitude at all time points examined . There was no evidence of treatment-by-CrCl interaction . The presence of declining renal function independently increased the risk for bleeding ( OR , 1.57;P < 0.001 for trend across categories ) , as did therapy with tirofiban , but no unexpected incremental risk of bleeding due to tirofiban was observed among lowest CrCl categories . Conclusions —Among patients with mild-to-moderate renal insufficiency in PRISM-PLUS , tirofiban was well tolerated and effective in reducing ischemic acute coronary syndrome complications BACKGROUND The potential benefit of dual antiplatelet therapy beyond 1 year after a myocardial infa rct ion has not been established . We investigated the efficacy and safety of ticagrelor , a P2Y12 receptor antagonist with established efficacy after an acute coronary syndrome , in this context . METHODS We r and omly assigned , in a double-blind 1:1:1 fashion , 21,162 patients who had had a myocardial infa rct ion 1 to 3 years earlier to ticagrelor at a dose of 90 mg twice daily , ticagrelor at a dose of 60 mg twice daily , or placebo . All the patients were to receive low-dose aspirin  and were followed for a median of 33 months . The primary efficacy end point was the composite of cardiovascular death , myocardial infa rct ion , or stroke . The primary safety end point was Thrombolysis in Myocardial Infa rct ion ( TIMI ) major bleeding . RESULTS The two ticagrelor doses each reduced , as compared with placebo , the rate of the primary efficacy end point , with Kaplan-Meier rates at 3 years of 7.85 % in the group that received 90 mg of ticagrelor twice daily , 7.77 % in the group that received 60 mg of ticagrelor twice daily , and 9.04 % in the placebo group ( hazard ratio for 90 mg of ticagrelor vs. placebo , 0.85 ; 95 % confidence interval [ CI ] , 0.75 to 0.96 ; P=0.008 ; hazard ratio for 60 mg of ticagrelor vs. placebo , 0.84 ; 95 % CI , 0.74 to 0.95 ; P=0.004 ) . Rates of TIMI major bleeding were higher with ticagrelor ( 2.60 % with 90 mg and 2.30 % with 60 mg ) than with placebo ( 1.06 % ) ( P<0.001 for each dose vs. placebo ) ; the rates of intracranial hemorrhage or fatal bleeding in the three groups were 0.63 % , 0.71 % , and 0.60 % , respectively . CONCLUSIONS In patients with a myocardial infa rct ion more than 1 year previously , treatment with ticagrelor significantly reduced the risk of cardiovascular death , myocardial infa rct ion , or stroke and increased the risk of major bleeding . ( Funded by AstraZeneca ; PEGASUS-TIMI 54 Clinical Trials.gov number , NCT01225562 . ) Since platelet cyclo-oxygenase is much more sensitive to inactivation by aspirin than is the enzyme in the arterial wall and low doses of aspirin may prevent thrombosis by blocking thromboxane synthesis , we conducted a r and omized , double-blind trial of aspirin ( 160 mg per day ) vs. placebo in 44 patients on chronic hemodialysis . The study was continued until there were 24 patients with thrombi and both groups had been under observation for a mean of nearly five months . Thrombi occurred in 18 of 25 ( 72 per cent ) of patients given placebo and 16 of 19 ( 32 per cent ) of those given aspirin ( P less than 0.01 ) . The incidence of thrombosis was reduced from 0.46 thrombi per patient month in the placebo group to 0.16 thrombi per patient month in the aspirin group ( p less than 0.005 ) . A dose of 160 mg of aspirin per day is an effective , nontoxic antithrombotic regimen in patients on hemodialysis BACKGROUND Blockade of the platelet glycoprotein IIb/IIIa receptor with abciximab ( a monoclonal-antibody Fab fragment directed against the receptor ) has been shown to diminish ischemic complications among patients undergoing high-risk coronary angioplasty or directional atherectomy but increases bleeding complications . The widespread applicability of this treatment is unknown , particularly in view of the observed risk of hemorrhage . METHODS In a prospect i ve , double-blind trial , we r and omly assigned patients undergoing urgent or elective percutaneous coronary revascularization at 69 centers to receive abciximab with st and ard-dose , weight-adjusted heparin ( initial bolus of 100 U per kilogram of body weight ) ; abciximab with low-dose , weight-adjusted heparin ( initial bolus of 70 U per kilogram ) ; or placebo with st and ard-dose , weight-adjusted heparin . The primary efficacy end point was death from any cause , myocardial infa rct ion , or urgent revascularization within 30 days of r and omization . RESULTS The trial was terminated at the first interim analysis , with 2792 of the planned 4800 patients enrolled . At 30 days , the composite event rate was 11.7 percent in the group assigned to placebo with st and ard-dose heparin ; 5.2 percent in the group assigned to abciximab with low-dose heparin ( hazard ratio , 0.43 ; 95 percent confidence interval , 0.30 to 0.60 ; P<0.001 ) ; and 5.4 percent in the group assigned to abciximab with st and ard-dose heparin ( hazard ratio , 0.45 ; 95 percent confidence interval , 0.32 to 0.63 ; P<0.001 ) . There were no significant differences among the groups in the risk of major bleeding , although minor bleeding was more frequent among patients receiving abciximab with st and ard-dose heparin . CONCLUSIONS Inhibition of the platelet glycoprotein IIb/IIIa receptor with abciximab , together with low-dose , weight-adjusted heparin , markedly reduces the risk of acute ischemic complications in patients undergoing percutaneous coronary revascularization , without increasing the risk of hemorrhage Background — Reduced renal function is associated with a poorer prognosis and increased bleeding risk in patients with acute coronary syndromes and may therefore alter the risk-benefit ratio with antiplatelet therapies . In the Platelet Inhibition and Patient Outcomes ( PLATO ) trial , ticagrelor compared with clopidogrel reduced the primary composite end point of cardiovascular death , myocardial infa rct ion , and stroke at 12 months but with similar major bleeding rates . Methods and Results — Central laboratory serum creatinine levels were available in 15 202 ( 81.9 % ) acute coronary syndrome patients at baseline , and creatinine clearance , estimated by the Cockcroft Gault equation , was calculated . In patients with chronic kidney disease ( creatinine clearance < 60 mL/min ; n=3237 ) , ticagrelor versus clopidogrel significantly reduced the primary end point to 17.3 % from 22.0 % ( hazard ratio [ HR ] , 0.77 ; 95 % confidence interval [ CI ] , 0.65 to 0.90 ) with an absolute risk reduction greater than that of patients with normal renal function ( n=11 965 ) : 7.9 % versus 8.9 % ( HR , 0.90 ; 95 % CI , 0.79 to 1.02 ) . In patients with chronic kidney disease , ticagrelor reduced total mortality ( 10.0 % versus 14.0 % ; HR , 0.72 ; 95 % CI , 0.58 to 0.89 ) . Major bleeding rates , fatal bleedings , and non – coronary bypass – related major bleedings were not significantly different between the 2 r and omized groups ( 15.1 % versus 14.3 % ; HR , 1.07 ; 95 % CI , 0.88 to 1.30 ; 0.34 % versus 0.77 % ; HR , 0.48 ; 95 % CI , 0.15 to 1.54 ; and 8.5 % versus 7.3 % ; HR , 1.28 ; 95 % CI , 0.97 to 1.68 ) . The interactions between creatinine clearance and r and omized treatment on any of the outcome variables were nonsignificant . Conclusions — In acute coronary syndrome patients with chronic kidney disease , ticagrelor compared with clopidogrel significantly reduces ischemic end points and mortality without a significant increase in major bleeding but with numerically more non – procedure-related bleeding . Clinical Trial Registration — URL : http://www.clinicatrials.gov . Unique identifier : NCT00391872 When constructing arteriovenous fistulas for haemodialysis in chronic renal failure patients , one of the main problems is still their clotting tendency . Ticlopidine is an effective inhibitor of platelet aggregation . In this r and omized double-blind study placebo or ticlopidine 250 mg twice daily was given to chronic uremic patients up to 4 weeks after construction of an arteriovenous fistula . 42 patients were recruited and 36 completed the trial . The fistula clotted in 8 patients on placebo and in 2 patients on ticlopidine . The difference is significant . This effect was achieved without an increased frequency of side effects compared with placebo . It is concluded that ticlopidine has a function as a thromboprophylactic drug in chronic uremic patients BACKGROUND Aggregation of platelets is the pathophysiologic basis of the acute coronary syndromes .  Eptifibatide , a synthetic cyclic heptapeptide , is a selective high-affinity inhibitor of the platelet glycoprotein IIb/IIIa receptor , which is involved in platelet aggregation . We tested the hypothesis that inhibition of platelet aggregation with eptifibatide would have an incremental benefit beyond that of heparin and aspirin in reducing the frequency of adverse outcomes in patients with acute coronary syndromes who did not have persistent ST-segment elevation . METHODS Patients who had presented with ischemic chest pain within the previous 24 hours and who had either electrocardiographic changes indicative of ischemia ( but not persistent ST-segment elevation ) or high serum concentrations of creatine kinase MB isoenzymes were enrolled in the study . They were r and omly assigned , in a double-blind manner , to receive a bolus and infusion of either eptifibatide or placebo , in addition to st and ard therapy , for up to 72 hours ( or up to 96 hours , if coronary intervention was performed near the end of the 72-hour period ) . The primary end point was a composite of death and nonfatal myocardial infa rct ion occurring up to 30 days after the index event . RESULTS A total of 10,948 patients were enrolled between November 1995 and January 1 
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Conclusions Major prevention with antiplatelet agents ( cardiovascular events and access failure ) , might outweigh the risk of bleeding , and there seemed to be an overall net benefit .