Cognitive Outcomes in Elderly High-Risk Patients After Off-Pump Versus Conventional Coronary Artery Bypass Grafting

Abstract

Background— It has been suggested that the risk of cerebral dysfunction is less with off-pump coronary artery bypass grafting (OPCAB) than with conventional coronary artery bypass grafting (CCAB). However, evidence for this statement is preliminary, and additional insight is needed. Methods and Results— The study was a substudy of the randomized Best Bypass Surgery trial that compared OPCAB with CCAB treatment with respect to intraoperative and postoperative mortality and morbidity in patients with a moderate to high level of predicted preoperative risk. The outcome was cognitive function. A total of 120 elderly patients (mean age 76 years, SD 4.5 years) underwent psychometric testing before surgery and at a mean of 103 (SD 15) days postoperatively with a neuropsychological test battery that included 7 parameters from 4 tests. Cognitive dysfunction was defined as the occurrence of at least 2 of the 7 possible deficits. Secondary analysis was performed on the basis of the definition of a 20% decline in cognitive scores compared with baseline, and with z score analysis. Cognitive dysfunction was identified in 4 of the 54 patients (7.4%, 95% confidence interval [CI] 2.1% to 17.9%) in the OPCAB group and 5 of the 51 patients (9.8%, 95% CI 3.3% to 21.4%) in the CCAB group. We found no difference in incidence of cognitive dysfunction between the groups regardless of the definition applied. Conclusions— In elderly high-risk patients, no significant difference was found in the incidence of cognitive dysfunction 3 months after either OPCAB or CCAB.