Warm versus cold cardioplegia in cardiac surgery: A meta-analysis with trial sequential analysis

Abstract

Objective: This meta-analysis aimed to compare clinical outcomes of warm and cold cardioplegia in cardiac surgeries in adult patients, with trial sequential analysis (TSA) used to determine the conclusiveness of the results.Methods: Electronic searches were performed on PubMed, Medline, Scopus, EM-BASE, and Cochrane library to identify all studies that compared warm and cold cardioplegia in cardiac surgeries. Primary end points were in-hospital or 30-day mortality, myocardial infarction, low cardiac output syndrome, intra-aortic balloon pump use, stroke, and new atrial fibrillation. Secondary end points were acute kidney injury, hospital length of stay, and intensive care unit length of stay. Prespecified subgroup analyses were performed for (1) studies published since publication of Fan and colleagues in 2010, (2) randomized controlled studies, (3) studies with low risk of bias, (4) coronary artery bypass graft surgeries, and (5) studies with cold blood versus those with cold crystalloid cardioplegia. TSA was performed to determine conclusiveness of the results, using on all outcomes without significant heterogeneity from studies of low risk of bias.Results: No significant differences were found between post-operative rates of mortality, myocardial infarction, low cardiac output syndrome, intra-aortic balloon pump use, stroke, new atrial fibrillation, and acute kidney injury between warm and cold cardioplegia. TSA concluded that current evidence was sufficient to rule out a 20% relative risk reduction in these outcomes.Conclusions: Concerning safety outcomes, current evidence suggests that the choice between warm and cold cardioplegia remains in the surgeon's preference.

Mechanisms of Acute Right Ventricular Injury in Cardiothoracic Surgical and Critical Care Settings: Part 2

“…During CPB the myocardium is protected by injection of cardioplegic solutions into the coronary circulation. [20][21][22] This can be achieved through an antegrade injection through the coronary arteries or retrograde through the coronary sinus. Limited evidence suggests that retrograde cardioplegia alone may not provide adequate RV myocardial protection as evidenced by contrast echocardiography, poor coronary ostial drainage and metabolic analyses.…”

“…20 A recent metaanalysis has shown that there is no significant outcome difference between cold vs warm cardioplegia which had previously been thought to be related to RVI. 21 The type of cardioplegia which may confer the highest level of RV myocardial protection is currently unknown. A network meta-analysis of 18 randomized controlled trials and 49 observational cohort studies (n = 18,191) which compared different types of commonly used well-defined cardioplegia solutions (crystalloid materials and mixtures of crystalloids and blood products) demonstrated that use of a 4:1 mixture of crystalloid solution and blood products (del Nido cardioplegia) may be associated with lower perioperative mortality.…”