A novel cold storage method that keeps donor hearts at 10 degrees Celsius is responsible for lower rates of severe primary graft dysfunction and improved recipient transplant outcomes versus conventional ice storage methods, a new Vanderbilt Health study found.
The study was chosen as the January Editor’s Choice article for this month’s issue of the American Journal of Transplantation. It is the largest study comparing 10-degrees-Celsius storage versus ice preservation following thoracoabdominal normothermic regional perfusion after donation after circulatory death heart transplantation.
Researchers retrospectively analyzed 147 adult transplant recipients at the Vanderbilt Transplant Center from October 2020 to October 2024. The cold storage system, a special type of cooler, was associated with a significantly reduced risk of severe primary graft dysfunction, post-bypass severe right ventricular depression and lower vasoactive-inotropic scores at 24 hours. Also reduced were incidence of recipient renal replacement therapy, intensive care unit length of stay, and six-month mortality.
“Overall, really across the board, all the outcomes were markedly improved when using this 10-degrees-Celsius preservation rather than using ice,” said Aaron Williams, MD, assistant professor of Cardiac Surgery and first author of the study.
Methods such as the cold storage system make it possible to preserve organs for longer after donation, Williams said. This expands the pool of available organs, allowing critically ill heart transplant patients more options to find a matching heart.
Traditional ice methods, the most common technique since transplantation began decades ago, can only preserve organs for about four hours, limiting the distance that doctors can go to get them and bring them back. But the cold storage method has been shown to preserve organs for as many as 11 hours, Williams said, affording organ donation teams the opportunity to travel across the country to find the perfect organ match.
“It is really helping us here at Vanderbilt to expand the donor pool by having the best preservation technology available so we can obtain these hearts and get them transplanted,” Williams said.
The study’s findings “warrant further validation in larger, prospective, multicenter studies to confirm the observed benefits,” the paper says. Williams said further study is also needed to compare outcomes with 10-degrees-Celsius storage versus other methods that store organs at 4 to 8 degrees Celsius.
