Importance of cerebral artery risk evaluation before off-pump coronary artery bypass grafting to avoid perioperative stroke

Abstract

Cerebrovascular atherosclerotic disease is a widely known risk factor for stroke after conventional coronary artery bypass grafting (CABG). The aim of this study is to evaluate the incidence of stroke in patients with significant cerebrovascular disease after off-pump CABG. In this retrospective study, 611 patients, who underwent off-pump CABG, were divided into high-risk (n=196) and low-risk groups (n=415) for perioperative stroke using preoperative brain magnetic resonance angiography/imaging and cervical Doppler sonography, and the incidence of stroke in the two groups was compared. No 'intra-operative' stroke was observed. However, seven patients (3.6%) in the high-risk group and one patient (0.2%) in the low-risk group developed 'delayed stroke' between the day of surgery and postoperative day 18 (mean postoperative day 8.8). The predominant aetiology of delayed stroke was thrombo-embolism. Assignment to the high-risk group had a significant association with the occurrence of delayed stroke (p=0.011). The person-time incidence rate of stroke in the high-risk group was much higher within 1 month (3.57) after CABG than beyond 1 month (0.14). Patients with significant cerebrovascular disease did not develop intra-operative stroke after off-pump CABG. However, these patients were likely to suffer from delayed stroke within 30 days of surgery.