Myocardial protection in adult cardiac surgery is commonly achieved with either multidose blood cardioplegia or single-dose del Nido crystalloid cardioplegia.

The aim of this systematic review and meta-analysis was to compare the outcomes of del Nido cardioplegia versus blood cardioplegia in adult cardiac surgery.

All English-language articles were searched in MEDLINE (PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar up to March 2020, to identify randomised control trials, prospective observational studies, and retrospective analyses (with or without propensity matching) reporting any or all of the primary and secondary endpoints. The primary endpoint was all-cause mortality. Secondary endpoints included cardiopulmonary bypass (CPB) and aortic cross-clamp (AoX) time; cardioplegia volume; need for defibrillation after AoX release; intraoperative glucose; postoperative myocardial enzyme release; postoperative left ventricular ejection fraction (LVEF); incidence of postoperative acute kidney injury (AKI), atrial fibrillation (AF), stroke, and low cardiac output syndrome (LCOS); postoperative blood transfusion; duration of mechanical ventilation; and length of intensive care unit (ICU) and hospital stay.

Twenty-nine (29) studies were included. There was no difference in the primary outcome of mortality between the two groups (odds ratio [OR], 1.18; 95% confidence interval [CI], 0.82–1.72 [p=0.37]). del Nido cardioplegia was associated with significantly shorter CPB (mean difference [MD], −7.42 minutes; 95% CI, −12.53 to −2.31 [p=0.004]) and AoX times (MD, −6.39 minutes; 95% CI, −10.30 to −2.48 [p=0.001]), and lower cardioplegia volumes. Significantly fewer patients required defibrillation after AoX release in the del Nido group. Intraoperative glucose homeostasis was better preserved in the del Nido group. Postoperative cardiac troponin T release and the number of patients needing transfusions were less in the del Nido group. No differences were seen in postoperative LVEF, or in the incidence of AKI, stroke, AF, and LCOS. Duration of mechanical ventilation, and length of ICU and hospital stay were similar.

Although this meta-analysis failed to find any mortality benefits with del Nido cardioplegia, significant benefits were seen in a number of intraoperative and postoperative variables. del Nido cardioplegia is a safe and favourable alternative to blood cardioplegia in adult cardiac surgery.