Simultaneous Heart and Kidney Transplantation utilizing Circulatory Death Donors in the United States

Objective: Heart transplants utilizing donors from circulatory death (DCD) allografts are rapidly growing with the potential to expand the donor pool. However, little is known about the use of DCD donors for simultaneous heart and kidney transplants (SHKT) compared to SHKT using brain death donors (DBD). Methods: From May 22, 2020, to September 30, 2023, 1,129 adult patients received SHKT (DCD, N=91 vs. DBD, N=1,038), identified using the United Network for Organ Sharing database, excluding other multi-organ transplants and re-transplants. A 1:3 ratio propensity score matching was performed using 17 recipient characteristics and 7 donor characteristics. A total of 91 DCD and 273 DBD matched cases were compared. Results: In the unmatched cohort, DCD recipients were older (DCD: 60 vs. DBD: 58 years, p=0.03) and had a lower rate of dialysis at transplant (27% vs. 40%, p=0.03) and status 1 to 2 patients (43% vs. 72%, p<.001). Donors were younger (30 vs. 32 years, p=0.02) in the DCD group. In the matched cohort, kidney delayed graft function (27% vs. 22%, p=0.29) was comparable, as were recipient survival (p=0.19), heart graft survival (p=0.19), and kidney graft survival (p=0.17). In multivariate Cox proportional hazards analysis, donor type (DCD) was not associated with an increased risk of mortality (HR=1.69, 95% Cl 0.90-3.16, p=0.10). Sub-group analysis showed that survival and freedom from graft failures were comparable between different modes of DCD recovery. The centers performing both DCD- and DBD-SHKT showed significantly shorter waitlist days with comparable transplant outcomes compared to centers that only performed DBD-SHKT. Conclusions: SHKT using DCD donors yields comparable survival and graft outcomes to those using DBD donors. These findings will guide treatment strategies for heart transplant candidates with kidney dysfunction, including the selection of donors and patients and safety net policy options.