Improved waitlist and comparable post-transplant outcomes in simultaneous heart-kidney transplantation under the 2018 heart allocation system

Objective: This study aimed to investigate the clinical trends and the impact of the 2018 heart allocation policy change on both waitlist and post-transplant outcomes in simultaneous heart-kidney transplantation in the United States. Methods: The United Network for Organ Sharing registry was queried to compare adult patients before and after the allocation policy change. This study included 2 separate analyses evaluating the waitlist and post-transplant outcomes. Multivariable analyses were performed to determine the 2018 allocation system's riskadjusted hazards for 1 -year waitlist and post-transplant mortality. Results: The initial analysis investigating the waitlist outcomes included 1779 patients listed for simultaneous heart-kidney transplantation. Of these, 1075 patients (60.4%) were listed after the 2018 allocation policy change. After the policy change, the waitlist outcomes significantly improved with a shorter waitlist time, lower likelihood of de -listing, and higher likelihood of transplantation. In the subsequent analysis investigating the post-transplant outcomes, 1130 simultaneous heart-kidney transplant recipients were included, where 738 patients (65.3%) underwent simultaneous heart-kidney transplantation after the policy change. The 90-day, 6-month, and 1 -year post-transplant survival and complication rates were comparable before and after the policy change. Multivariable analyses demonstrated that the 2018 allocation system positively impacted risk-adjusted 1 -year waitlist mortality (sub-hazard ratio, 0.66, 95% CI, 0.51-0.85, P < .001), but it did not significantly impact risk-adjusted 1 -year post-transplant mortality (hazard ratio, 1.03; 95% CI, 0.72-1.47, P 1/4 .876). Conclusions: This study demonstrates increased rates of simultaneous heartkidney transplantation with a shorter waitlist time after the 2018 allocation policy change. Furthermore, there were improved waitlist outcomes and comparable early post-transplant survival after simultaneous heart-kidney transplantation under the 2018 allocation system.