On-pump beating coronary artery bypass grafting in patients with left ventricular systolic dysfunction

Abstract

aspirin responsiveness is rarely tested. A recent study in patients undergoing percutaneous coronary intervention showed an increased risk of myocardial ischemia and mortality in patients with high on-aspirin platelet reactivity (e.g., reduced aspirin responsiveness) (1). The aim of this prospective cohort study was to evaluate the prognostic impact of reduced aspirin responsiveness on long-term mortality and major thromboembolic and/or cardiac events in patients undergoing coronary artery graft bypass (CABG) surgery by a point-of-care platelet function analyzer. Methods. We included 304 patients undergoing elective isolated CABG surgery with chronic aspirin intake until at least two days before surgery. Impedance platelet aggregometry (Multiplate s , Roche Diagnostics, Rotkreuz, Switzerland) was performed directly before and on the first day after surgery. Reduced aspirin responsiveness was defined as area under the curve in ASPI test (AUC ASPI) Z300 units in the preoperative assessment according to an own former study (2). All physicians in charge of the peri-and postoperative therapy were blinded for the results of aspirin responsiveness. The primary outcome was defined as composite of all-cause mortality and/or major adverse cardiac or thromboembolic events within 1 year. Results. Thirty-seven of 304 patients (12%) showed reduces aspirin responsiveness. Thirthy-one patients (10%) reached the primary endpoint. However, there was no difference in outcomes between patients with normal and reduced aspirin responsiveness in the Kaplan-Meyer survival analysis (P by log rank test ¼ 0.504). Additional multivariate analysis adjusted for logistic EuroSCORE I and postoperative high-sensitivity troponin T levels also showed no association of reduced aspirin responsiveness with adverse outcome (hazard ratio 0.576 (95% confidence interval 0.128-2.585; P¼0.471). Analyses on postoperative Multiplate s values were similar to analyses based on preoperative assessment. Discussion. The results of the present study suggest that reduced aspirin responsiveness as evaluated by perioperative Multiplate s analyses is not associated with increased incidence of major adverse cardiac and thromboembolic events and mortality within 1 year after elective isolated CABG surgery. Our conclusion is limited by the rather low number of events and included patients.