Aspirin in coronary artery surgery: 1-year results of the Aspirin and Tranexamic Acid for Coronary Artery Surgery trial

Background: Aspirin may reduce the risk of vascular graft thrombosis after cardiovascular surgery. We previously reported the 30-day results of a trial evaluating aspirin use before coronary artery surgery. Here we report the 1-year outcomes evaluating late thrombotic events and disability-free survival. Methods: Using a factorial design, we randomly assigned patients undergoing coronary artery surgery to receive aspirin or placebo and tranexamic acid or placebo. The results of the aspirin comparison are reported here. The primary 1-year outcome was death or severe disability, the latter defined as living with a modified Katz activities of daily living score < 8. Secondary outcomes included a composite of myocardial infarction, stroke and death from any cause through to 1 year after surgery. Results: Patients were randomly assigned to aspirin (1059 patients) or placebo (1068 patients). The rate of death or severe disability was 4.1% in the aspirin group and 3.5% in the placebo group (relative risk, 1.17; 95% confidence interval, 0.76-1.81; P = .48). There was no significant difference in the rates of myocardial infarction (P = .11), stroke (P = .086), or death (P = .24), or a composite of these cardiovascular end points (P = .68). With the exception of those with a low European System for Cardiac Operative Risk Evaluation score (P = .03), there were no interaction effects on these outcomes with tranexamic acid (all tests of interaction P > .10). Conclusions: In patients undergoing coronary artery surgery, preoperative aspirin did not reduce death or severe disability, or thrombotic events through to 1 year after surgery.