The Final Rule in a Bind: What We Are Learning From Suboptimal Simultaneous Heart-Kidney Outcomes and Potential Solutions to the Problem.

Background: The 2018 revision of the adult Heart Allocation Policy (aHAP) led to a notable increase in the rate of simultaneous heart-kidney transplants (SHKT) in the United States. However, this policy has faced criticism for its inability to enhance post-transplant survival rates or decrease mortality among SHKT recipients on the waitlist, although high-quality kidneys are used.

Methods: We analyzed data from the Organ Procurement and Transplantation Network, covering 1549 SHKT cases from 2015 to 2021. The study assessed 1-y post-transplant outcomes, including all-cause heart and kidney graft failures and adverse kidney outcomes such as end-stage kidney disease, significantly reduced kidney function or the need for retransplantation. Using a propensity score-matching approach, we compared 2 cohorts: patients treated before and after the policy implementation in October 2018.

Results: The multivariable Cox proportional hazard models indicated a significant increase in mortality (hazard ratio [HR] 1.62; 95% confidence interval [CI], 1.10-2.37) and all-cause graft failures for both heart (HR 1.59; 95% CI, 1.08-2.33) and kidney (HR 1.39; 95% CI, 1.03-1.85) during the period after the new aHAP implementation. One year post-transplant, the incidence of adverse kidney outcomes was 6.8% under the new aHAP compared with 5.3% in the previous period among survivors (P = 0.33).

Conclusions: The suboptimal outcomes of SHKT under the new aHAP, alongside its potential impacts on kidney-alone transplant candidates, suggest a need for regular monitoring of SHKT policies. This is crucial to ensure that the intentions of the Final Rule regarding equity and utility are effectively met.