Cognitive function after on or off pump coronary artery bypass grafting

Abstract

Objective: To investigate cognitive outcome after on and off pump coronary artery bypass grafting. Methods: Seventy patients between 50 and 80 years with stable angina pectoris, ejection fraction >30%, serum creatinine ≪ 150 μmol/l, and lack of tight main stem stenosis were randomized to on or off pump coronary artery bypass grafting. Standardized neuropsychological tests evaluated attention, verbal and visuo-spatial short-term and working memory, verbal learning, delayed recall, visuo-motor speed, and aspects of executive functions. Levels of anxiety and depression were also investigated. Testing was performed before and at 1 week, 1 and 6 months after surgery. Results: There was no difference in cognitive impairment (defined as a 20% reduction in at least 20% of the tests) between groups. The incidence at 1 week post-operatively was 57% in the on pump group and 58% in the off pump group, after 1 month 30% and 12% and after 6 months 19% and 15%, respectively (p for interaction = 0.19). There was no difference between groups in anxiety (p = 0.18) or depression (p = 0.48). Conclusions: This prospective, randomized study showed no differences in post-operative cognitive function after on pump compared to off pump coronary artery bypass grafting in low risk patients.