Does Off-pump Coronary Revascularization Reduce the Release of the Cerebral Markers, S-100β and NSE?

OBJECTIVES: The aims of this study were to (1) compare the release of S-100 beta and NSE in off-pump coronary artery bypass grafting (CABG) versus on-pump surgery; (2) investigate whether the S-100 beta and NSE serum concentrations correlate with cardiopulmonary bypass (CPB) duration. MATERIALS AND METHODS: Between October 2002 and May 2004, 42 patients undergoing first time CABG surgery were enrolled in the study. The exclusion criteria were: LVEF<35%, age>70 years, previous myocardial infarction, REDO surgery, the presence of valvular heart disease and/or cerebrovascular disease, abnormal preoperative carotid vessels angiography, coronary artery disease involving the distal circumflex artery, renal dysfunction, coagulopathy. The patients were randomly assigned either to undergo on-pump CABG surgery [group I, n=24 patients] or off-pump CABG [group II, n=18 patients]. Blood was not re-transfused from the cardiotomy suction. All patients presenting haemolysis were excluded from the study. RESULTS: The preoperative S-100beta was 0.13+/-0.08 (microg/l) and NSE 7+/-1.5 (microg/l) in group I and 0.12+/-0.1 (microg/l) and 6.9+/-2.7 (microg/l), respectively in group II. Six hours after the surgery, S-100beta in patients of group I reached a maximum level of 1.38+/-0.4 (microg/l) and NSE of 17.7+/-6.5 (microg/l) compared to 0.5+/-0.11 (microg/l) [S-100B] and NSE 8.6+/-4.2 (microg/l) in group II (p=0.001). Three (12%) patients in group I and none (0%) in group II suffered postoperative delirium, p=0.247. No strokes occurred linear regression analysis revealed a strong correlation between cardiopulmonary bypass duration and S-100beta and NSE peak levels, p<0.0021 (r(2)=0.36) and p<0.0001 (r=0.81), respectively. CONCLUSION: Coronary artery bypass surgery with CPB causes a significantly greater increase in NSE and S-100beta serum levels than off-pump surgery and correlates with CPB duration.