Aspirin before coronary artery surgery

Myles and colleagues recently reported in the New England Journal of Medicine the results from their Aspirin and Tranexamic Acid for Coronary Artery Surgery (ATACAS) study (1).This was a multicenter trial evaluating the effects of aspirin in patients undergoing coronary surgery.This study found no difference in the rates of bleeding complications or thromboembolic events, which contradict previous studies (2,3).The ATACAS trial randomly assigned patients undergoing coronary artery surgery to receive 100 mg of aspirin or placebo.During this trial 2,100 patients were enrolled.Of these 2,100 patients, 1,047 were randomly assigned to receive aspirin and 1,053 were randomly assigned to receive placebo.Patients either received aspirin 100 mg or placebo 1 to 2 hours prior to coronary artery surgery.The primary outcomes of the study were death and thrombotic events (myocardial infarction, stroke, pulmonary embolus, renal failure).The primary outcome occurred in 19.3% of the aspirin group and in 20.4% of the placebo group.There was also no difference observed in the rates of myocardial infarction or bleeding complications between the two groups.There have been numerous papers written on the topic of pre-operative aspirin administration in patients undergoing cardiac surgery.A recent meta-analysis with a total of 13 different trials and over 2,300 patients did find that pre-operative aspirin reduced the incidence of perioperative MI but also lead to an increase in the rate of blood transfusions, bleeding, and surgical re-exploration (2).As the authors of the ATACAS trial point out, their study contradicts portions of this study.One potential reason for a difference between the two studies could be related to the dose used (100 mg).The authors point out that this dose is known to be cardioprotective but could potentially have a decreased risk of bleeding compared with higher doses.The ATACAS trial was