Point‐of‐Care Platelet Function Testing Predicts Bleeding in Patients Exposed to Clopidogrel Undergoing Coronary Artery Bypass Grafting: Verify Pre‐Op TIMI 45—A Pilot Study

Background Guidelines recommend delaying coronary artery bypass grafting (CABG) for 5 days after discontinuing clopidogrel. However, platelet function may recover quicker in certain individuals. Hypothesis We hypothesized that perioperative measurement of platelet function with a point‐of‐care P2Y12 inhibitor assay could predict bleeding during CABG in patients exposed to clopidogrel. Methods Verify Pre‐Op TIMI 45 was a prospective pilot study of 39 patients on clopidogrel who subsequently underwent CABG. Preoperative on‐treatment platelet reactivity was assessed with VerifyNow P2Y12 Reaction Units (PRU), with higher PRU indicating more reactive platelets. Outcomes were stratified by PRU quartiles, as well as prespecified cutpoints for the lowest quartile (PRU 173), a cutpoint for major bleeding determined by the Youden index using receiver operator curve analysis (PRU 207), and clopidogrel resistance (PRU 230). Results Patients in higher PRU quartiles experienced smaller decreases in hemoglobin and hematocrit (P