Platelet activity measured by a rapid turnaround assay identifies coronary artery bypass grafting patients at increased risk for bleeding and transfusion complications after clopidogrel administration.

ABSTRACT

BACKGROUND: We sought to establish a metric for easily estimating bleeding and transfusion risks for cardiac surgery patients after antiplatelet agent use. METHODS: Deidentified records of patients who underwent coronary artery bypass grafting (CABG) at our institution (January 2010-June 2011) were searched for patients without identified risk factors for excessive bleeding who underwent documented P2Y12 testing after clopidogrel administration (n = 276). Clinical outcomes were analyzed according to whether preoperative platelet function was higher (platelet reactivity units [PRUs], ≥237) or lower (PRU, <237) and according to preoperative PRU cutoffs high (>290, or no clopidogrel), intermediate (200-290), or low (<200). RESULTS: Eighty-five patients (57%) received allogeneic blood products at 24 hours or less postoperatively 33 (22%) received fresh frozen plasma, and 57 (38%) received platelets. The median 12-hour chest tube output (CTO) was 350 mL (interquartile range, 260-490 mL); CTO was "high" (>437 mL) in 62 (42%) of the clopidogrel-treated patients. Lower-PRU patients were more likely to receive coagulation factors (odds ratio [OR], 2.82; P = .0004) and to have high CTO or coagulation factor transfusion (OR, 2.35; P = .02) than higher-PRU patients. Likewise, intermediate- and low-PRU patients had incrementally greater incidences of high CTO (OR, 1.72; P = .002) and coagulation factor transfusion (OR, 2.08; P < .0001) than high-PRU/no clopidogrel patients. High CTO or coagulation factor transfusion was more frequent in intermediate-PRU (OR, 2.67; P = .02) and low-PRU (OR, 5.08; P = .0002) patients than in high-PRU/no clopidogrel patients. CONCLUSIONS: Among clopidogrel-treated CABG patients, preoperative platelet function testing can identify those at increased risk for postoperative bleeding and transfusion.