Short-term clinical outcomes for intermittent cold versus intermittent warm blood cardioplegia in 2200 adult cardiac surgery patients

BACKGROUND: Aim of the present study was to compare clinical outcome of intermittent cold (ICC) versus intermittent warm (IWC) blood cardioplegia in different cardiosurgical procedures.

METHODS: Two thousand one hundred and eighty-eight patients were retrospectively divided into 5 groups: isolated coronary artery bypass surgery (CABG; N.=1203), isolated aortic valve surgery (AVR; N.=374), isolated mitral valve surgery (MVR; N.=151), combined AVR+CABG (N.=390), and combined MVR+CABG (N.=70). Myocardial protection was performed by ICC (N.=1578) or IWC (N.=610) blood cardioplegia. In logistic regression models the effect of cardioplegia on 30-day mortality, IABP/ECLS (intraaortic balloon-pump/extracorporal life support) implantation, transient neurological deficit, stroke, renal failure, new-onset atrial fibrillation, and troponin T release was estimated. Potential modifications of the effect of cardioplegia by logistic EuroSCORE, cross-clamping time, ejection fraction, and op-status elective versus urgent/emergent were investigated.

RESULTS: There were no statistically significant differences between ICC and IWC regarding 30-day mortality (odds ratio [OR]=0.70; 95% CI: 0.39-1.23; P=0.219), IABP/ECLS support (OR=0.60; 95% CI: 0.23-1.55; P=0.294), transient neurological deficit (OR=0.90; 95% CI: 0.65-1.24; P=0.541), stroke (OR=0.79; 95% CI: 0.40-1.54; P=0.495), renal failure (OR=1.07; 95% CI: 0.57-1.99; P=0.825), and atrial fibrillation (OR=0.96; 95% CI: 0.77-1.18; P=0.713) across all 5 groups. Troponin t release was significantly higher in ICC compared to IWC (by 0.029±0.015 ng/mL; P=0.046) in univariate analysis; this effect was lowered by risk-factor adjustment and lost statistical significance. The effect of cardioplegia was not significantly different between groups. In urgent/emergent surgery ICC resulted in a significantly higher 30-day mortality (OR=3.03; P=0.024) compared to IWC.

CONCLUSIONS: The comparison of IWC and ICC blood cardioplegia in different cardiosurgical procedures showed no statistical significant difference in myocardial protection. The use of ICC, however, appeared overall associated with a slightly better clinical outcome except in patients undergoing urgent/emergent CABG where IWC led to a reduction in 30-day-mortality.