Does Early Post-operative Administration of Aspirin Influence the Risk of Bleeding After Coronary Artery Bypass Graft Surgery? A Prospective Observational Study

Background: Aspirin has a proven role in preventing thrombotic diseases. However, given its anti-platelet activity, it is often assumed that its early post-operative administration significantly increase the amount of post-operative bleeding. Aim: The aim of this study was to determine whether early post-operative administration of aspirin influence the risk of bleeding in patients undergoing coronary artery bypass graft (CABG) surgery. Methods: In a prospective observational study, 100 consecutive patients undergoing first time elective CABG surgery were include in the study. Patients received a low dose of aspirin (75-150 mg per day) either 1 hours (the early aspirin group; n=43) or 6 hours after surgery (the late aspirin group; n=57). Total mediastinal blood drainage, blood drainage after 6 hours, incidences of re-operation for the control of bleeding and transfusion of red blood cells (RBCs) and blood products were recorded and followed until chest tube removal. Results: The groups were found to be matched for the confounding variables and no significant differences were found between post-aspirin bleeding (p=0.37), RBCs and blood product usage (p=0.90) or incidences of re-operation for control of bleeding (p=1.00) between the two groups. Conclusions: Early administration (1 hour after surgery) of aspirin did not appear to increase the risk of post-operative bleeding in patients undergoing CABG. Thereby, its early administration in such cases may be considered. Although further well-designed randomized controlled trials to confirm the safety and efficacy of early administration of aspirin after CABG surgery are warranted.