Abstract 16246: Hypothermic and Hyperkalemic Perfusion Prolonged the Ischemic Time in Porcine Model of Donor After Circulatory Death

Abstract

Introduction: There is a worldwide shortage of donors in heart transplantation(HTx), and one way to expand donor sources is HTx from donors after circulatory death (DCD). Several nations have successfully incorporated DCD HTx into clinical practices. However, the limitation of ischemic time from cardiac arrest is one of the significant barriers to the expansion of DCD. Hypothesis: Hypothermic and hyperkalemic (HT-HK) perfusion can prolong the time from cardiac arrest to heart procurement. Methods: A model of brain death was created by balloon occlusion of the intracranial cavity of pigs, and the ventilator was stopped to create a controlled DCD model. To mimic HTx, we adopted a model in which the ascending aorta was cross clamped (AXC) under open chest in pigs, systemic circulation was maintained using ECMO, and then the AXC was released to resume heartbeat and evaluate cardiac function. 1. To examine the limitation of the warm ischemic time (WIT), we performed systemic perfusion including the heart after a certain period from cardiac arrest, and evaluate whether the heartbeat resumed or not. 2. Following cardiac arrest, we performed HT-HK perfusion, accompanied by chest opening, AXC for cardioplegia infusion, and simultaneous systemic warming and potassium correction. Then, we evaluate whether the heartbeat resumed and cardiac function. 3. the preserved heart by HT-HK perfusion was transplanted orthotopically into the other pig and evaluated its cardiac function. Results: 1. ECMO reperfusion within 30 minutes after WIT led to heartbeat resumption, while reperfusion after 60 minutes did not. 2. Among the six pigs subjected to HT-HK perfusion, one had cardiac arrest during brain death preparation, and another went into ventricular fibrillation after the release of AXC. However, four pigs resumed heartbeat and normal contraction with an average time of 94.0±9.2 minutes from the cardiac arrest. Cardiac function after HTx from DCD with HT-HK perfusion was favorable, with a left ventricular ejection fraction of 63% after weaning from cardiopulmonary bypass. Conclusions: DCD with hypothermic and hyperkalemic perfusion prolonged the time from cardiac arrest to procurement, and exhibited favorable post-transplant cardiac function, suggesting its usefulness.