Aspirin in Patients With Previous Percutaneous Coronary Intervention Undergoing Noncardiac Surgery.

<bold>Background: </bold>Uncertainty remains about the effects of aspirin in patients with prior percutaneous coronary intervention (PCI) having noncardiac surgery.<bold>Objective: </bold>To evaluate benefits and harms of perioperative aspirin in patients with prior PCI.<bold>Design: </bold>Nonprespecified subgroup analysis of a multicenter factorial trial. Computerized Internet randomization was done between 2010 and 2013. Patients, clinicians, data collectors, and outcome adjudicators were blinded to treatment assignment. (ClinicalTrials.gov: NCT01082874).<bold>Setting: </bold>135 centers in 23 countries.<bold>Patients: </bold>Adults aged 45 years or older who had or were at risk for atherosclerotic disease and were having noncardiac surgery. Exclusions were placement of a bare-metal stent within 6 weeks, placement of a drug-eluting stent within 1 year, or receipt of nonstudy aspirin within 72 hours before surgery.<bold>Intervention: </bold>Aspirin therapy (overall trial, n = 4998; subgroup, n = 234) or placebo (overall trial, n = 5012; subgroup, n = 236) initiated within 4 hours before surgery and continued throughout the perioperative period. Of the 470 subgroup patients, 99.9% completed follow-up.<bold>Measurements: </bold>The 30-day primary outcome was death or nonfatal myocardial infarction; bleeding was a secondary outcome.<bold>Results: </bold>In patients with prior PCI, aspirin reduced the risk for the primary outcome (absolute risk reduction, 5.5% [95% CI, 0.4% to 10.5%]; hazard ratio [HR], 0.50 [CI, 0.26 to 0.95]; P for interaction = 0.036) and for myocardial infarction (absolute risk reduction, 5.9% [CI, 1.0% to 10.8%]; HR, 0.44 [CI, 0.22 to 0.87]; P for interaction = 0.021). The effect on the composite of major and life-threatening bleeding in patients with prior PCI was uncertain (absolute risk increase, 1.3% [CI, -2.6% to 5.2%]). In the overall population, aspirin increased the risk for major bleeding (absolute risk increase, 0.8% [CI, 0.1% to 1.6%]; HR, 1.22 [CI, 1.01 to 1.48]; P for interaction = 0.50).<bold>Limitation: </bold>Nonprespecified subgroup analysis with small sample.<bold>Conclusion: </bold>Perioperative aspirin may be more likely to benefit rather than harm patients with prior PCI.<bold>Primary Funding Source: </bold>Canadian Institutes of Health Research. [ABSTRACT FROM AUTHOR]