Off-pump or minimized on-pump coronary surgery--initial experience with Circulating Endothelial Cells (CEC) as a supersensitive marker of tissue damage

Off-pump-coronary-artery-bypass-grafting (OPCAB) and minimized-extracorporeal-circulation (Mini-HLM) have been proposed to avoid harmful effects of cardiopulmonary-bypass (CPB). Controversies exist whether OPCAB is still superior in perioperative outcome. Circulating endothelial cells (CEC) are sensitive markers of endothelial damage and are significantly elevated in conventional-CPB-procedures as compared to Mini-HLM-revascularisation. Therefore, CEC might be of specific value in evaluating effectiveness of Mini-HLM and OPCAB as currently applied less-invasive coronary procedures.

Conceptional advantages of minimized CPB systems (ROCsafe™) result in morbidity and mortality comparable with OPCAB procedures. Mini-HLM therefore minimizes CPB-related systemic and organ injury as demonstrated by low CEC-values which indicates intact endothelial integrity. Furthermore, Mini-HLM combines OPCAB-benefits with low morbidity in high-risk patients while facilitating more complete revascularization in complex patients.

76 coronary patients were randomly assigned either to OPCAB (n = 34) or to Mini-HLM (ROCsafe™, Terumo Inc., n = 42) procedures. Perioperative data, clinical and serological outcome and measurements of CEC-release and parameters of endothelial function (v.Willebrand-Factor, soluble-thrombomodulin) perioperatively (pre-operative-baseline, post-Mini-HLM/release of OPCAB-stabilizer, 6 h, 12 h, 24 h and 5 days postoperatively) were obtained and compared by ANOVA models including repeated-measures-analysis.

Mean graft-number was 3.06 ± 0.72 in Mini-HLM-patients and 1.89 ± 0.74 in OPCAB-patients (p < 0.001). However, ventilation-, ICU- and total-hospital duration were comparable between groups as well as chest-tube-drainage, transfusion requirements, hemodynamics and catecholaminergic support (p > 0.05). CEC-release did not differ between groups (p = 0.274) and was generally within normal limits, Troponin-T levels where not significanty different (p = 0.108). No myocardial infarctions, strokes or deaths occurred, neuron specific enolase (NSE) did not show any differences between groups (p = 0.194).