Response to hypercapnia as a tool to assess cardiac recovery in a porcine model of DCD heart transplantation.

Abstract

The advent of normothermic, ex-situ heart perfusion (ESHP) enables new options for evaluation of cardiac grafts. Donation after circulatory death (DCD) is a promising solution to improve heart transplantation rates, but current ESHP evaluation approaches are recognized as suboptimal for DCD grafts. We aimed to develop a vascular function test for cardiac graft assessment during ESHP using a porcine model of DCD. Explanted hearts were perfused unloaded for 3 hours followed by left ventricular loading for 1 hour to measure cardiac recovery. During unloaded perfusion by pressure, hypercapnic vascular function tests were performed by briefly increasing COlevels and measuring responses in coronary flow. Coronary flow was effectively increased, it correlated with several measures of cardiac recovery (p≤0.05 for all) and was not affected by adenosine infusion. Our data provide the first evidence of a vascular function test that may help to improve evaluation of DCD cardiac grafts and is amenable to implementation in current clinical protocols.