Innovative Strategies for Organ Preservation in Heart Transplantation: Uniform Cooling Preservation and <em>Ex-situ</em> Normothermic Perfusion

Nearly 4,500 heart transplantations are performed annually worldwide. Given the current organ shortage, extended criteria are frequently accepted nowadays for the selection of donor hearts. There is therefore a need for optimized preservation technology to prevent the risk of primary graft dysfunction. The Uniform Cooling Preservation (UCP) is an FDA-approved and CE-marked approach applied in clinical practice since 2020. UCP provides stable cold storage for safe preservation of cardiac allografts, including those procured in donors with extended criteria. Decreased utilization of mechanical circulatory support, along with reduced hospital stay after transplant, has been associated with the use of UCP. Normothermic ex-situ heart perfusion (ESHP) has been developed to ensure safe and prolonged preservation of cardiac allografts. Thanks to ex-situ normothermic oxygenated blood perfusion, ESHP technology allows for continuous monitoring of the donor heart during transportation. Myocardial viability for transplant is characterized by a progressive decrease in lactate level in the perfusate. ESHP has recently been applied for the rehabilitation of cardiac allografts procured after controlled circulatory death. In the present report, we aim to describe technical features of UCP and ESHP preservation technologies. Early clinical outcomes will be discussed, focusing on the rate of severe primary graft dysfunction after transplant.