Cardioplegic arrest can be induced by various methods, fueling a long-standing controversy about their comparative merit. We aim to compare cardioplegic methods in coronary artery disease.

PubMed, Embase, and Cochrane databases were interrogated for randomized trials that compared various cardioplegic methods in adult patients undergoing elective isolated coronary artery bypass grafting. Differences in cardioplegic composition – crystalloid or blood, route of delivery – antegrade or retrograde, and temperature, were evaluated in a network meta-analysis. The endpoints were mortality, myocardial infarction, insertion of intra-aortic balloon pump, low cardiac output syndrome, increased inotropic support, as well as cardiopulmonary bypass time, aortic cross-clamp time, intensive care stay, hospital stay, new onset atrial fibrillation, reperfusion ventricular fibrillation, and neurologic event. Confidence In Network Meta-Analysis web application was employed.

75 studies were included, with 6131 patients receiving one of 13 cardioplegic methods. Warm ante/retrograde blood cardioplegia was associated with fewer deaths (P-score 0.81), fewer intra-aortic balloon pumps (P-score 0.77), and shorter intensive care (P-score 0.69) and hospital stay (P-score 0.81). Cross clamp time was shorter with crystalloid cardioplegias, while reperfusion ventricular fibrillation was less frequent with warm blood cardioplegias. Cold cardioplegias were associated with lower rates of new onset atrial fibrillation and stroke. Confidence varied greatly across the endpoints.

The outcomes of this network study indicate presumable advantages of warm ante/retrograde blood cardioplegia in elective isolated coronary artery bypass grafting. Under the light of certain biases and mixed confidence, the results should be cautiously interpreted. More studies are needed.