Effect of Preoperative Aspirin Use on Postoperative Bleeding and Perioperative Myocardial Infarction in Patients Undergoing Coronary Artery Bypass Surgery

Background- Continuation or discontinuation of aspirin use in the preoperative period for patients scheduled for elective cardiac surgery has continued to be controversial. In this study, we tried to evaluate clinical outcomes (mortality, postoperative bleeding and perioperative myocardial infarction) in patients who underwent first elective coronary artery bypass grafting and received aspirin during the preoperative period. Methods- The study was a prospective, randomized and single-blinded clinical trial. Two-hundred patients were included in the study and divided into two groups. One group received aspirin 80-160 mg and in the other group, aspirin was stopped at least for seven days before operation. The primary end points of the study were in-hospital mortality rate and hemorrhage-related complications (postoperative blood loss in the intensive care unit, reexploration for bleeding and red blood cell and non-red blood cell transfusion requirements). The secondary end point was perioperative myocardial infarction. Results- There were no differences in patients’ characteristics among aspirin users and non-aspirin users. We found a significant difference between postoperative blood loss (608پ}359.7 ml vs. 483پ}251.5 ml; P=0.005) and red blood cell product requirements (1.32پ}0.97 units packed cells vs. 0.94پ}1.02 units packed cells; P=0.008) in the two groups. There was no significant difference between the two groups regarding platelet requirements and the rate of in-hospital mortality and reexploration for bleeding. Similarly, we found no significant difference in the incidence of definite and probable perioperative myocardial infarction (P=0.24 and P=0.56, respectively) and in-hospital mortality between the two groups. Conclusion- Preoperative aspirin administration increased postoperative bleeding and red blood cell requirements with no effect on mortality, reexploration rate and perioperative myocardial infarction (Iranian Heart Journal 2008; 9 (2):18-22).