The Impact of Preoperative Clopidogrel on Outcomes After Coronary Artery Bypass Grafting

Abstract

This study evaluated the impact of preoperative clopidogrel exposure on outcomes of coronary artery bypass grafting (CABG). Patients undergoing isolated CABG from January 2010 to February 2018 at a single institution were included. Primary stratification was based on exposure to clopidogrel within 5 days of CABG. Primary outcomes included blood product transfusion and mediastinal reexploration for bleeding. Secondary outcomes included early and late mortality, major postoperative complications, and hospital readmissions. Multivariable Cox regression was used to evaluate the risk-adjusted impact of preoperative clopidogrel on post-CABG mortality. Isolated CABG was performed in 7048 patients, including 1240 (18%) who had received clopidogrel within 5 days. Patients who received preoperative clopidogrel had higher rates of transfusions (53.4% vs 40.3%, P < .001) and reoperation for bleeding (3.0% vs 2.0%, P= .02). Most postoperative complication rates were similar, although those exposed to clopidogrel had higher rates of postoperative stroke (2.3% vs 1.2%, P= .002) and prolonged ventilation (10.2% vs 7.1%, P < .001). Clopidogrel exposure did not impact unadjusted or risk-adjusted 30-day, 1-year, or 5-year mortality or readmission. Discontinuing clopidogrel for at least 3 days preoperatively mitigated but did not eliminate the increased risk of blood transfusions after CABG. CABG can be safely performed in patients with recent clopidogrel exposure with no increased risk of early or late mortality. However, CABG should be delayed for at least 5 days, if clinically feasible, to minimize transfusions and reoperation risk. In patients with more urgent indications, delaying CABG at least 3 days can mitigate but not eliminate the increased bleeding risk.