Neurocognitive Function, Cerebral Emboli, and S100β after On-pump and Off-pump Coronary Artery Bypass Surgery: a Randomised Study.
Back to 86th Annual Meeting
Back to Program Outline
Objective:
Neurocognitive impairment can be a debilitating complication following coronary artery bypass surgery (CABG). Cardiopulmonary bypass, in particular cerebral emboli, has been implicated. Neurocognitive function, cerebral emboli and a serum marker of cerebral injury, S100β, were compared in patients undergoing on-pump and off-pump CABG.
Methods:
212 patients admitted for CABG were randomised to on-pump (n=104) and off-pump (n=108). Embolic signals (ES) were detected with bilateral transcranial Doppler ultrasound of the middle cerebral artery. Neurocognitive tests were administered pre-operatively, on discharge from hospital, at 6 weeks and 6 months following surgery. Serum S100β was measured before surgery, intra-operatively and at 48 hours. Composite neurocognitive scores were derived using principal component analysis and were compared between the two groups, using analysis of covariance to adjust for baseline values.
Results:
At discharge from hospital the adjusted composite neurocognitive score was 0.25 standard deviations (SDs) greater in the off-pump than on-pump group (95% CI 0.05 to 0.45; p=0.01). There was no significant difference at 6 weeks (0.09 SDs, 95% CI -0.11 to +0.30; p=0.4) and 6 months (-0.002 SDs, 95% CI -0.23 to +0.23; p=1.0). Median number of ES was 1605 (751-2473) during on-pump and 9 (4-27) in off-pump CABG (p<0.001). Age, length of education and on-pump status were independent predictors of the pre-discharge neurocognitive score (p=0.02, 0.03 & 0.006 respectively). The ratio of mean intra-operative S100β in on-pump to that in off-pump was 1.92 (95% CI 1.64 to 2.25, p<0.001). After 48 hours the ratio was 1.01 (95% CI 0.91 to 1.14, p=0.9). Only the 48 hour S100β level for off-pump surgery correlated with neurocognitive score at discharge (Kendall's taub = -0.16, p=0.03).
Conclusions:
Cerebral emboli are more prevalent during on-pump CABG. At discharge from hospital neurocognitive function is better after off-pump surgery, although we cannot conclude that this is due to the lower embolic load. However, the difference in neurocognitive function does not persist at 6 weeks and 6 months. S100β cannot be reliably used to determine neurocognitive function.
Back to 86th Annual Meeting
Back to Program Outline
