Mid-Term Reassessment of Waitlist and Posttransplant Outcomes Under the 2018 Heart Allocation System: Improved...

This study evaluates clinical trends and mid-term waitlist and posttransplant outcomes following the 2018 heart allocation policy change.

The United Network for Organ Sharing registry was queried to analyze adult waitlisted and transplanted patients undergoing isolated heart transplantation. Two analyses were conducted: (1) waitlist and (2) posttransplant outcomes. For the waitlist analysis, candidates were stratified into seasonally matched prepolicy (October 18, 2012-June 30, 2017) and postpolicy (October 18, 2018-June 30, 2023) groups, with a 1-year follow-up period. Waitlist outcomes included 1-year cumulative incidences of transplantation, delisting due to death/clinical deterioration, and all-cause survival from the initial waitlisting. For the posttransplant analysis, recipients were stratified into seasonally matched prepolicy (October 18, 2014-June 30, 2018) and postpolicy (October 18, 2018-June 30, 2020) groups, with a 4-year follow-up period. Posttransplant outcomes included 4-year survival. Propensity score-matching and multivariable Cox regression were used for risk adjustment.

Under the 2018 allocation system, there was a continued shift toward the use of older donors, longer graft ischemic times, and shorter waitlist durations. In the waitlist analysis, 30 620 waitlisted candidates were analyzed, with 14 908 (48.7%) listed after the policy change. The postpolicy candidates had a higher 1-year cumulative incidence of transplantation (subhazard ratio, 2.06 [95% CI, 2.00-2.12]; P<0.001) and a lower 1-year cumulative incidence of delisting (subhazard ratio, 0.58 [95% CI, 0.53-0.63]; P<0.001) compared with the prepolicy candidates. In addition, the postpolicy candidates had significantly improved 1-year survival from initial waitlisting compared with the prepolicy candidates (90.0% versus 86.8%; P<0.001). In the posttransplant analysis, 13 712 recipients were analyzed, with 4597 (33.5%) transplanted following the policy change. The 4-year post-transplant survival was similar between the groups (83.3% versus 82.8%; P=0.593). Furthermore, the comparable 4-year post-transplant survival persisted in the propensity score-matched comparison and multivariable Cox regression.

Despite the changes in donor and recipient profiles following the 2018 allocation system change, this mid-term reassessment demonstrates its success in significantly improving waitlist survival, while maintaining comparable posttransplant survival.