Effects of preoperative aspirin in coronary artery bypass grafting: a double-blind, placebo-controlled, randomized trial.

OBJECTIVE: This trial was undertaken to determine the safety and efficacy of preoperative aspirin administration in a contemporary cardiac surgical practice setting.

METHODS: This randomized, double-blind, parallel-group, single-center trial involved patients with stable coronary artery disease who were assigned to receive either 300 mg of aspirin or placebo the night before coronary bypass surgery. Using a random digit table, patients were allocated to receive the tablet from 1 of the 40 coded bottles containing either aspirin or placebo. Patients, surgeons, anesthetists, and investigators were all masked to treatment allocation. The primary safety end points were as follows: more than 750 mL of bleeding during the first postoperative 12 hours and more than 1000 mL of total discharge from the chest drains. The secondary efficacy end point was a composite of cardiovascular death, myocardial infarction, or repeat revascularization.

RESULTS: A total of 390 patients were allocated to aspirin (387 analyzed) and 399 to placebo (396 analyzed). The follow-up median was 53 months. Fifty-four placebo recipients and 86 aspirin recipients bled more than 750 mL in the first 12 hours (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.25-2.63), while total chest drain discharge was above 1000 mL in 96 placebo and 131 aspirin recipients (OR, 1.60; 95% CI, 1.17-2.18). Preoperative aspirin decreased the long-term hazard of nonfatal coronary event (infarction or repeat revascularization)-hazard ratio (HR), 0.58 (95% CI, 0.33-0.99)--and tended to decrease the hazard of a major cardiac event (cardiovascular death, infarction, or repeat revascularization--HR, 0.65 [95% CI, 0.41-1.03]).

CONCLUSIONS: Performing coronary grafts on aspirin is associated with increased postoperative bleeding but may decrease the long-term hazard of coronary events.