Impact of discontinuation of aspirin and clopidogrel before off-pump coronary artery bypass grafting on postoperative bleeding and transfusion requirement

Abstract

Objective: To investigate the influence of different discontinuation time of aspirin and clopidogrel before off-pump coronary artery bypass grafting (OPCABG) on postoperative bleeding and blood products transfusion requirement. Methods: Three hundred and fifty-three coronary artery disease patients who underwent OPCABG from January 2017 to January 2018 at Department of Cardiac Surgery, Zhongshan Hospital, Fudan University were retrospectively analysed. There were 268 males and 85 females, aged (66.0±9.1)years. All patients were divided into three groups: (1) guideline-recommended group: patients who discontinued clopidogrel for >5 days without discontinuing aspirin before surgery; (2) without discontinuing group: patients who discontinued clopidogrel for ≤5 days without discontinuing aspirin before surgery; (3) discontinuing group: patients who discontinued clopidogrel for >5 days with discontinuing aspirin before surgery. Postoperative bleeding recorded as chest tube drainage (CTD) volume and blood products transfusion requirement and perioperative complications were recorded. CTD volumes within 12 hours after surgery between groups were compared by Mann-Whitney U tests, CTD volumes after 12 hours postoperatively were compared by repeated measures analysis of variance and blood products transfusion and complications incidence were compared by χ(2) test or Fisher's precise test. Results: The 12 hours CTD volumes of guideline-recommended group, without discontinuing group, discontinuing group after surgery were 280(153) ml (M(Q(R))), 291(229) ml, 225(161) ml, respectively. There were no significant differences in postoperative 12 hours CTD volumes (P=0.865), red blood cells transfusion incidence (χ(2)=2.626, P=0.149) and fresh frozen plasma (FFP) transfusion incidence (χ(2)=1.258, P=0.324) between guideline-recommended group and without discontinuing group. However, the 12 hours CTD volumes were significantly higher in guideline-recommended group patients compared with disconutinuing group patients (U=5 247, P=0.002). No significant differences were observed in red blood cells (χ(2)=0.182, P=0.757) and FFP (χ(2)=0.083, P=0.839) transfusion rate between these two groups. Repeated measures analysis of variance indicated that when patients began to take antiplatelet drugs (aspirin and clopidogrel) after 12 hours postoperatively, the change of CTD volumes beyond 12 hours after surgery didn't differ either between guideline-recommended group and without discontinuing group (F=0.019, P=0.941) or between guideline-recommended group and discontinuing group (F=2.447,P=0.113). Besides, the incidence of perioperative arrhythmia was significantly higher in guideline-recommended group patients compared with without discontinuing group patients (4.8% vs. 0, χ(2)=5.073, P=0.038). Conclusions: OPCABG patients who discontinued aspirin before surgery had lower postoperative 12 hours CTD volumes but similar blood products transfusion rate and CTD volumes beyond 12 hours postoperatively compared with patients adhering to the current guideline-recommended protocol. And for patients who discontinued clopidogrel for ≤5 days, postoperative CTD volumes and blood products transfusion requirement were similar but the incidence of perioperative arrhythmia was significantly lower compared with guideline-treated patients.