Short-term and long-term neurocognitive outcome in on-pump versus off-pump CABG

Objective: Neuropsychological dysfunctions are considered to be important complications of coronary artery bypass graft surgery (CABG). We examined the frequency of neuropsychological abnormalities occurring in patients undergoing CABG with (on-pump) and without (off-pump) cardiopulmonary bypass. Methods: Neuropsychological assessment with seven cognitive tasks was performed one day before, 6-7 days after (n = 49) and 6 months after (n = 35) surgery. The subgroup undergoing on-pump surgery (n = 30 at 7 days and n = 22 at 6 months) was demographically comparable to the off-pump subgroup. The on-pump group included more multiple vessel disease. Results: Repeated measures multivariate analysis of variance (using surgical group as a between-subjects factor) on the group data revealed no significant differences neither immediately after surgery nor at 6 months after surgery, compared with the preoperative performance. There were no significant differences between the on-pump and off-pump groups in post-operative neuropsychological performance soon after surgery. A significant difference was found between the two groups 6 months after surgery, with more favorable results for the off-pump group. Individual comparisons revealed that 59% of the patients of both groups undergoing CABG showed evidence of cognitive impairment soon after surgery. In 11% of the patients (all on-pump), the cognitive sequelae persisted at follow-up. Conclusion: This study showed no short-term difference between the on-pump and off-pump CABG groups. The long-term cognitive outcome revealed more favorable results for the off-pump group. Although a preference to operate multiple vessel disease with classical cardiopulmonary bypass (CPB) has to be considered, the present study shows evidence for a different pattern of early decline and late recovery of cognitive functions in patients undergoing CABG with and without CPB. (C) 2002 Elsevier Science B.V. All rights reserved.