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

Abstract

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. 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 risk-adjusted hazards for 1-year waitlist and post-transplant mortality. 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 = .876). This study demonstrates increased rates of simultaneous heart-kidney 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.