Six-Month Survival Following Heart Transplant After Donor Circulatory Death Is Noninferior to Transplant After Donor Brain Death

Survival at 6 months after transplantation with a donor heart that was reanimated and assessed after circulatory-death was found to be noninferior to patient survival among recipients of the standard care transplantation using a donor heart that had been preserved in cold storage after brain-death, according to the results of a new study published in The New England Journal of Medicine.

The multicenter, unblinded, randomized study analyzed data from 180 patients who underwent transplantation, with 90 patients assigned to each cohort. After accounting for protocol violations, 80 patients underwent transplantation using a heart from a donor after circulatory death while 86 patients used a heart from a donor after brain death, the study authors explained.

Notably, donor hearts from those who underwent circulatory death were able to be preserved and analyzed in situ, which was made possible through extracorporeal machine perfusion; this allows for reanimation of the heart and evaluation for transplantation suitability, according to the investigators.

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During the study, the primary efficacy endpoint was the 6-month survival rate among patients who underwent transplantation after considering prespecified donor and recipient risk factors, while a secondary endpoint was donor-heart utilization rate, according to the study authors.

Results of the trial showed that the risk-adjusted 6-month survival rate in patients who received a heart from a donor after circulatory-death was 94% (95% CI, 88 to 99), while the rate was 90% (95% CI, 84 to 97) among recipients of a heart from a donor after brain-death.

In the overall population, the risk-adjusted 6-month survival rate was 93% (95% CI, 88 to 99) in recipients of a heart from a donor after circulatory death, in comparison to a rate of 90% (95% CI, 83 to 96) among patients who received a heart from a donor after brain death, the study authors explained.

When analyzing the unadjusted survival rate at 6 months, the results of the study showed it was consistent in the as-treated population (in circulatory-death donor recipients, 76 of 80 [95%; 95% CI, 88 to 99] vs. brain-death donor recipients, 75 of 84 [89%; 95% CI, 81 to 95] and in the overall population (94% [95% CI, 88 to 98] vs. 89% [95% CI, 80 to 94]).

When examining the donor-heart utilization rate, 90 of 101 hearts transplanted from circulatory-death donors that were preserved using the perfusion system were successfully transplanted to the recipient, resulting in an 89% donor-heart utilization rate, according to the study authors.

Until recently, heart donors for transplants were only those who were brain-dead due to the ability to evaluate the heart for function and viability for transplantation in situ. Yet advancements in in situ and ex situ perfusion of hearts in donors after circulatory death have resulted in policies that allow transplantation from circulatory-death donors, according to the authors. This has allowed for the high–and growing–demand for heart transplants to become more manageable, according to the study authors. This may, hopefully, allow more patients to receive donations as well.

The study authors noted there were some potential limitations. In order to protect patients who were on the transplant waiting list, the design of the trial was unblinded and allowed for treatment crossover in case a patient in the circulatory-death group matched with a donor who was in the brain-death group. The researchers unanimously voted that to restrict the hearts that patients could receive would be unethical, according to the authors.

This decision led to multiple developments; namely, patients in the circulatory-death group were able to undergo transplantation faster than the brain-death group. Additionally, patients in the circulatory-death group tended to be younger with less hospitalization in comparison with their counterparts, according to the study authors.

This could have led to higher survival rates among the circulatory-death group, but investigators said they included these potential factors when determining risk-adjusted analysis.

“The reported results of this trial are short term; long-term results and potential late com­plications are unknown,” the study authors wrote. “Five-year follow-up would permit better understanding of the long-term ramifications of transplantation of a heart obtained from a donor after circulatory death.”

Reference

Schroder J N, Patel CB, DeVore AD, et al. Transplantation outcomes with donor hearts after circulatory death. N Engl J Med. 2023;388:2121-2131. doi:10.1056/NEJMoa2212438