On-pump coronary surgery with and without cardioplegic arrest: comparison of inflammation, myocardial, cerebral and renal injury and early and late health outcome in a single-centre randomised controlled trial

Objective: To assess the safety and efficacy of on-pump beating heart coronary surgery on organ function, and early and late health outcome as compared with conventional technique. Methods: A total of 81 patients were randomised to (1) coronary surgery with cardiopulmonary bypass (CPB) and cardioplegic arrest (CA) (on-pump with CA, n=41) or to (2) CPB without CA (on-pump without CA, n=40). Primary outcomes included serial measurement of interleukins (IL-6, IL-8 and IL-10) for inflammation, troponin I for myocardial injury, protein S100 for cerebral injury and creatinine clearance (CrCl) and urinary N-acetyl-β-d-glucosaminidase (NAG) for renal injury. In-hospital health outcome and 5-year event-free survival were secondary outcomes. Results: Baseline and intra-operative characteristics were similar between groups. A marked release of ILs was observed in both groups, but no significant differences between the groups were found (IL-6 +9%, 95% confidence interval (CI) -15% to +39%, p=0.49; IL-8 +4%, 95% CI -34% to +63%, p=0.86; IL-10 -0.1%, 95% CI -19% to +21%, p=0.93). Troponin I rose in both groups and was on average 34% higher in the on-pump without CA group but this did not reach statistical significance (95% CI -0.4% to +87%, p=0.08). S100 protein was higher in the on-pump without CA group at 12h (p=0.04) but did not differ at other times (p=0.16). The level of CrCl was higher 1h in the on-pump without CA group (+23%, 95% CI +1% to +50%, p=0.04), but not thereafter. NAG release was similar in both groups (+1% 95% CI -23% to +33%, p=0.91). Early and 5-year health outcomes were similar. Conclusions: On-pump without CA coronary surgery does not provide any obvious advantage when compared with the conventional technique of on-pump with CA in elective patients. Both techniques provide a comparable degree of inflammatory activation, myocardial, cerebral and renal injury with similar 5-year event-free survival.