Assessing Intraoperative Bleeding Risk in Patients Undergoing Coronary Artery Bypass Grafting with Prior Exposure to Clopidogrel: Single Center Retrospective Analysis

Abstract

In patients undergoing coronary artery bypass grafting (CABG), intraoperative and postoperative major bleeding requiring blood transfusions and surgical reexploration is associated with increased mortality and morbidity. Our study hypothesized that exposure to clopidogrel is not significantly associated with increased risk for intraoperative bleeding, even when administered less than 5 days before CABG. We also aimed to determine variables associated with intraoperative packed red blood cell (iPRBC) transfusion. Patients of both sexes aged 18 years or older who underwent CABG from July 1, 2011 to December 31, 2012 were included in the analysis. Study population consisted of 2 groups—clopidogrel arm and nonclopidogrel arm. Patients were included in clopidogrel arm if they were exposed to clopidogrel in the past (as one of their home medications or received the medication for first time during the index hospitalization), whereas patients who never received clopidogrel were included in nonclopidogrel arm. We identified a total of 303 adult patients who underwent CABG with a mean age was 64.5 years. Mortality rate in our study was 0.99% (n = 3) with increased mortality in women as compared with men (3.27% vs. 0.41%, P = 04). The mean iPRBC transfused were 1.68 units, with higher units being transfused in women as compared with men (2.23 vs. 1.49 units, respectively, P = 0.03) and no significant difference between clopidogrel and nonclopidogrel arms (1.92 vs. 1.50, respectively, P = 0.18). After multivariate analysis, age [odds ratio (OR) = 1.03, P = 0.01], female sex (OR = 2.61, P = 0.006) and hypertension (OR = 7.10, P = 0.02) predicted increased iPRBC transfusion. Clopidogrel or nonclopidogrel status was not associated with increased iPRBC transfusion (OR = 1.06, P = 0.81). iPRBC transfusion rates were similar in both arms with age, female sex, and hypertension being an independent predictor of iPRBC transfusion.