Heart Transplantation with Donor Hearts Harvested After Circulatory Death

Heart Transplantation with Donor Hearts Harvested After Circulatory Death (Donors after Circulatory Death Heart Trial)

Conventionally, heart transplantation is done using donor hearts obtained after brain death of the donor. That means the heart was still beating at the time of harvesting. Now a study published in the New England Journal of Medicine has reported on the utility of reanimated hearts obtained after circulatory death [1]. This if found to be useful in the long term, is certainly going to increase the pool of donor hearts available for the patients in the long waiting list for heart transplantation. It was a multi-center, randomized, non-inferiority trial with assignment in 3:1 ratio.

Candidates in the circulatory death group would receive a heart after circulatory death of the donor or a heart from a donor after brain death if that heart was available first. This would protect the chance of a candidate to receive a heart transplant without unnecessary delay. Those in the brain death group would receive only a heart that has been preserved with the use of traditional cold storage after the brain death of the donor.

Analysis of 166 transplant recipients were done in the as-treated primary analysis. 80 had received a heart from a circulatory death donor and 86 had received a heart from a brain death donor. The risk adjusted six month survival in the circulatory death donor group was 94% and 90% in the brain death donor group, with P<0.001 for non-inferiority. There was no significant difference between the groups regarding serious adverse events associated with the heart graft at 30 days after transplantation. The donor heart in the study group had been reanimated and assessed with the use of extracorporeal nonischemic perfusion after circulatory death.

Only donors in the age group of 18 to 49 years were considered for the circulatory death group. Age more than 49 years was not an exclusion criteria for brain death donors. Functional warm ischemia time in the circulatory death group was 30 minutes or less. Functional warm ischemia time was defined as time from mean arterial blood pressure less than 50 mm Hg or peripheral oxygen saturation less than 70% to aortic cross clamp and administration of cold cardioplegia. Eligible circulatory death donors were those who became donors after controlled withdrawal of life support and subsequent cardiac arrest and cardiocirculatory arrest.

An editorial [2] accompanying the article mentioned that there are many persons who are willing to be organ donors when there is no hope for survival, 80% of whom have severe brain injury, but do not meet criteria for brain death and are unable to donate hearts. The use of perfusion techniques allows reanimation of hearts that have ceased functioning after circulatory death. These hearts are then tested to rule out any inury that would prohibit donation. Nearly 90% of the hearts from circulatory death donors were ultimately transplanted.

15% of recipients of a heart from a circulatory death donor had severe graft dysfunction in the first 30 days while it occurred only in 5% of hearts from a brain death donor, which was a predictable difference. But such graft dysfunction appeared to be manageable, as graft failure and retransplantation was needed only in two recipients, both of whom were in the control group, eligible for only heart from a brain death donor.

A critical knowledge gap was also pointed out by the editorial. Organs from circulatory death donors were rarely transplanted to the sickest patients in the study. They were given to patients with more stable condition on the transplant waiting list. Only one heart from a circulatory death donor was transplanted to a recipient in the severest category on the waiting list while five transplants from brain death donors were given to recipients in such category.

References

1. Schroder JN, Patel CB, DeVore AD, Bryner BS, Casalinova S, Shah A, Smith JW, Fiedler AG, Daneshmand M, Silvestry S, Geirsson A, Pretorius V, Joyce DL, Um JY, Esmailian F, Takeda K, Mudy K, Shudo Y, Salerno CT, Pham SM, Goldstein DJ, Philpott J, Dunning J, Lozonschi L, Couper GS, Mallidi HR, Givertz MM, Pham DT, Shaffer AW, Kai M, Quader MA, Absi T, Attia TS, Shukrallah B, Sun BC, Farr M, Mehra MR, Madsen JC, Milano CA, D’Alessandro DA. Transplantation Outcomes with Donor Hearts after Circulatory Death. N Engl J Med. 2023 Jun 8;388(23):2121-2131. doi: 10.1056/NEJMoa2212438. PMID: 37285526.
2. Sweitzer NK. Safely Increasing Heart Transplantation with Donation after Cardiac Death. N Engl J Med. 2023 Jun 8;388(23):2191-2192. doi: 10.1056/NEJMe2303928. PMID: 37285530.