Warmer Heart Storage May Improve Donor Organ Outcomes

Storing donor hearts at a slightly warmer temperature of 10°C, as opposed to the standard static cold storage (SCS) range of 4-8°C, may lead to improved post-transplant outcomes, according to preliminary findings from a retrospective analysis. This research, presented at the International Society for Heart and Lung Transplantation (ISHLT) 2024 Annual Meeting, challenges the long-held belief that colder is always better for organ preservation.

The analysis examined data from 1,170 adult heart transplant recipients who received organs preserved using either SCS at 4-8°C or at 10°C. The study found a statistically significant difference in the primary outcome, which was defined as the composite of graft failure or death within one year of transplantation. Specifically, patients receiving hearts stored at 10°C experienced a lower incidence of this adverse outcome compared to those whose hearts were stored at colder temperatures. The study did not specify the exact percentage difference but indicated a "marked difference" in outcomes, suggesting a clinically relevant benefit.

Further investigation into secondary outcomes also revealed potential advantages of the warmer storage. While the data is still being analyzed, initial results indicated that the 10°C storage group might experience fewer instances of primary graft dysfunction (PGD), a serious complication that can occur immediately after transplantation. PGD is a major cause of early graft loss and patient mortality following heart transplantation. The study's authors noted that the precise mechanisms behind these observed differences are not yet fully understood but hypothesize that the warmer temperature might better preserve cellular function and reduce ischemic injury during the preservation period.

This preliminary research suggests a potential paradigm shift in donor heart preservation protocols. Current guidelines from organizations like The International Society for Heart and Lung Transplantation generally recommend SCS at temperatures between 4°C and 8°C. However, if these findings are validated by further research and clinical trials, it could lead to revised guidelines and practices, ultimately aiming to improve the success rates and long-term survival of heart transplant recipients. The implications extend beyond heart transplantation, potentially prompting similar investigations into optimal storage temperatures for other solid organs. The full results of the analysis are expected to be published following peer review.