Cognitive outcomes in elderly high-risk patients after off-pump versus conventional coronary artery bypass grafting - A randomized trial

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.