Abstract
BACKGROUND: The impact of continuous distribution on allocation of multiorgan transplantation (MOT) involving lungs remains unexplored. Here we characterize how continuous distribution has affected lung-involved MOT. METHODS: We conducted a retrospective study using the United Network for Organ Sharing database. Adults listed for lung-MOT between March 9, 2021, and March 8, 2025, were included. The lung allocation score (LAS) era included the 24 months prior to March 9, 2023, and the composite allocation score (CAS) era comprised 24 months after March 9, 2023. Primary outcomes included transplantation rate, waitlist mortality, and 6-month composite outcome (graft rejection and death) assessed with Kaplan-Meier methods and Poisson regression to estimate transplantation rate and waitlist mortality. Post-transplantation survival was modeled using Cox proportional hazards. RESULTS: Among 498 lung-MOT candidates listed for transplantation during the study period (274 heart-lung, 106 lung-liver, and 101 lung-kidney), 349 underwent transplantation (205 heart-lung, 77 lung-liver, and 60 lung-kidney). The transplantation rate per 100 patient-years increased significantly for all combinations under CAS (heart-lung, 90.5 vs 172.9; lung-liver, 57.9 vs 254.5; lung-kidney, 118.8 vs 194.2; P < .05 for all), while waitlist mortality remained similar between eras (heart-lung, 8.0 vs 19.4; lung-liver, 15.1 vs 18.9; lung-kidney, 23.8 vs 36.0; P > .05 for all). The six-month post-transplantation composite outcome was comparable in the 2 eras (87.0% vs 87.6%; P = .832). CONCLUSIONS: The transition from LAS to CAS enhanced access to transplantation for lung-MOT, while waitlist mortality remained similar. Short-term post-transplant composite outcomes did not differ between eras, supporting the feasibility of CAS for lung-MOT candidates without negatively impacting early outcomes.