Background: We evaluated early postoperative neurocognitive functions of patients undergoing coronary artery bypass grafting (CABG) performed under cardiopulmonary bypass or beating heart.

Methods: Fifty patients undergoing elective CABG were randomized into two groups: conventional (n=25; mean age 55±8 years) or off-pump CABG (n=25; mean age 60±10 years). Neuropsychological assessments were performed one day before the operation and on the postoperative seventh day using six cognitive tests. Mini-Mental State Examination and neuropsychological test batteries were conducted to evaluate attention, concentration, memory, visual-spatial recognition, and psychomotor performance.

Results: The two groups were similar with regard to clinical and demographic features and the number of distal and proximal anastomoses. No mortality or major neurological complications occurred. Preoperative neuropsychological assessments yielded similar scores in two groups. Postoperatively, both groups exhibited significant deterioration in neurocognitive tests. However, compared to patients in the off-pump CABG group, the scores of Mini-Mental State Examination, frontal lobe functions, cognitive tests, late memory tests, and visualspatial recognition were significantly lower in the conventional CABG group.

Conclusion: Neurocognitive functions are depressed after both on-pump and off-pump coronary surgeries. However, our data suggest that neurocognitive functions are better preserved during off-pump CABG.

Keywords : Cardiopulmonary bypass/adverse effects; coronary artery bypass/adverse effects; cognition disorders/etiology; neuropsychological tests