Preoperative clopidogrel and outcomes in patients with acute coronary syndrome undergoing coronary artery bypass surgery

Abstract

Objective: The optimal preoperative antiplatelet strategy for patients with acute coronary syndrome (ACS) requiring surgical revascularization remains unclear because of competing risks of bleeding and ischemic events. We evaluated the effect of clopidogrel within 5 days before coronary artery bypass grafting (CABG) on outcomes in patients with ACS.

Methods: Consecutive patients with ACS who underwent isolated CABG at a single center were included in this retrospective study. The primary outcome was a composite of death, myocardial infarction, and stroke within 30 days after surgery. Secondary outcomes were CABG-related major bleeding and perioperative transfusion. Inverse probability weighting using propensity score was performed to evaluate the risk-adjusted effect of preoperative clopidogrel on outcomes.

Results: Of 5543 patients with ACS, 820 (14.8%) patients continued clopidogrel within 5 days before CABG. After adjustment for differences in baseline factors, clopidogrel use ≤5 days before CABG was associated with significantly increased odds of the primary composite outcome (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.16-2.29; P = .005), stroke (OR, 3.13; 95% CI, 1.82-5.39; P < .001), major bleeding (OR, 2.01; 95% CI, 1.56-2.58; P < .001), and transfusion (OR, 2.05; 95% CI, 1.82-2.30; P < .001). The effects of preoperative clopidogrel use ≤5 days on primary outcome and major bleeding were greater in patients older than 65 years.

Conclusions: Among patients with ACS undergoing CABG, clopidogrel therapy within 5 days before surgery was associated with increased odds of major cardiac and cerebrovascular events and bleeding complications than discontinuing clopidogrel for >5 days.

Keywords: acute coronary syndrome; antiplatelet therapy; clopidogrel; coronary artery bypass grafting; outcomes.