Heart transplant remains the most durable treatment for end-stage congestive heart failure. Since the first successful human heart transplant performed by Barnard in 1967, advances in organ procurement, understanding of organ preservation, and immunosuppression have enabled successful heart transplant outcomes in a progressively complex recipient population. With an increasing number of patients living with congestive heart failure, the need for donor hearts far outpaces the number available for transplantation at any given time.

Limiting ischemia time (be it cold or warm) and adequate preservation of the donor organ remain vital to ensuring the best outcomes for heart transplant. Currently, cold static storage is the mainstay for cardiac preservation and transport for most heart transplants performed in the United States. After aortic cross-clamping at the procurement, a crystalloid-based preservation solution is flushed into the aortic root, perfusing the coronary system to provide hypothermic arrest of metabolism, preserve myocyte cellular components, and minimize ischemic reperfusion injury. After the heart is removed from the donor, it is placed into cold static storage for transport, with an optimal temperature maintained at 4 °C to 8 °C. The hypothermic environment slows myocyte metabolism to promote organ viability.⁶

While cold static storage is the most common method for cardiac preservation today, it is far from ideal. Harmful effects from cold ischemic storage include cellular swelling, extracellular edema, acidosis, and calcium overload. Accumulation of harmful oxygen radicals precipitates ischemic reperfusion injury and endothelial damage. To minimize primary graft dysfunction, cold static storage times are currently limited to 4 to 6 h. Thus, transplant centers may be geographically limited by how far a donor organ can be transported to reach a recipient.

A variety of other techniques are being studied that seek to expand the potential donor pool, including donation after circulatory death (DCD), normothermic regional perfusion, and ex vivo machine perfusion (MP) systems. Here, we review techniques already in routine clinical use, ones that that have been studied in the laboratory, and those currently being investigated in clinical trials.