The impact of clopidogrel therapy on postoperative bleeding after robotic-assisted coronary artery bypass surgery

Abstract

OBJECTIVES: The purpose of this study was to determine whether patients undergoing robotic-assisted coronary artery bypass graft surgery (CABG) on clopidogrel had an increased risk of bleeding complications compared with those not on clopidogrel. METHODS: From 2008 to 2011, 322 patients underwent robotic-assisted CABG either as an isolated procedure or as part of a hybrid coronary revascularization procedure (HCR). Patients were classified according to whether they received clopidogrel within 5 days of surgery or intraoperatively (n = 64) compared with those who never received or who had discontinued clopidogrel therapy >5 days before surgery (n = 258). A propensity analysis using 31 preoperative variables was used to control for confounding variables. In a subgroup analysis, patients undergoing one-stage HCR (clopidogrel load 600 mg in odds ratio (OR) prior to stenting) were compared with patients in the clopidogrel group who underwent two-stage HCR. RESULTS: In the Clopidogrel group, the mean interval between surgery and last dose of clopidogrel was 2.1 ± 1.5 days. Compared with the No Clopidogrel group, the Clopidogrel group had greater 24-h chest tube drainage (1003 ± 572 vs 782 ± 530 ml, P = 0.004) and more blood transfusions (35.9%, 23 of 64 patients vs 20.9%, 54 of 258 patients, P = 0.01). On logistic regression analysis, there was greater 24-h chest tube drainage in the Clopidogrel group (+198 ml, P = 0.02) and a significantly higher incidence of blood transfusion (OR = 2.30, P = 0.01). In the subgroup analysis, patients undergoing one-stage HCR (n = 17) had greater 24-h chest tube drainage compared with patients undergoing two-stage HCR (1262 vs 909 ml, P = 0.03). CONCLUSIONS: Patients undergoing robotic-assisted CABG on clopidogrel had more postoperative bleeding and a higher incidence of blood transfusion. Therefore, despite a less invasive approach, surgery should be delayed in these patients when possible.