Cardioplegia strategy in isolated CABG: a comparative evaluation of del Nido, microplegia and St. Thomas II

The optimal cardioplegia strategy in adult coronary artery bypass grafting (CABG) remains controversial. This study compared the efficacy of del Nido, microplegia, and St. Thomas II cardioplegic solutions for myocardial protection using clinical, biochemical, and echocardiographic parameters in isolated CABG.

In this prospective single-center study, 157 adult patients undergoing isolated CABG were grouped according to cardioplegia strategy: del Nido (n = 88), microplegia (n = 32), and St. Thomas II (n = 37). Baseline demographic, laboratory, and echocardiographic characteristics were comparable. Intraoperative variables included cross-clamp (XC) and cardiopulmonary bypass (CPB) times, cardioplegia characteristics, defibrillation requirement, and vasoactive support. Postoperative assessment comprised arterial blood gas values, cardiac biomarkers, organ function tests, echocardiographic findings, clinical outcomes, and in-hospital mortality.

Total cardioplegia volume and number of doses were significantly lower in the del Nido group (p < 0.001). XC time was shorter with St. Thomas II (p < 0.001), likely due to operative technique differences. Intraoperative defibrillation and adrenaline requirement were more frequent in the St. Thomas II group (p = 0.001 and p = 0.027). Postoperative arterial blood gas parameters and end-organ function were similar. The del Nido group demonstrated significantly lower 1-h troponin I, 1-h CK-MB, and 24-h troponin I levels compared with St. Thomas II (p = 0.002, p = 0.004, p = 0.013). Postoperative increases in troponin I and CK-MB were also lower with del Nido. LVEF decline was least pronounced in the microplegia group (p = 0.013). ICU and hospital stays were significantly longer with St. Thomas II (p = 0.034 and p = 0.027). Morbidity and in-hospital mortality were comparable.

Del Nido cardioplegia and microplegia provide comparable and effective myocardial protection, both demonstrating superior biochemical preservation compared with St. Thomas II. Del Nido offers practical advantages without increasing morbidity or mortality.