Post-transplant outcomes by bridging strategy: A nationwide multicenter study of heart transplant recipients in Korea

Background Extracorporeal membrane oxygenation (ECMO) is prioritized in Korea’s heart transplant (HTx) allocation system to reduce waitlist mortality, but post-transplant outcomes remain a concern. We compared post-transplant outcomes among HTx recipients bridged with ECMO, left ventricular assist device (LVAD), or without mechanical circulatory support (non-MCS). Methods We retrospectively analyzed 1021 adult HTx recipients enrolled in the Korean Organ Transplant Registry (2014-2023). Patients were categorized according to bridging strategy at transplantation (ECMO n = 357, LVAD n = 137, non-MCS n = 527). Outcomes included primary graft dysfunction (PGD), in-hospital mortality, any treated rejection, coronary allograft vasculopathy, infection requiring hospitalization, and post-transplant mortality. Results ECMO bridging was associated with significantly higher risks of severe PGD (adjusted HR 3.68 vs non-MCS; 2.23 vs LVAD). In-hospital mortality was highest in ECMO recipients (17.9%) compared with LVAD-bridged (4.4%) and non-MCS recipients (4.4%) (P < 0.001). Kaplan-Meier analysis demonstrated significantly lower survival in the ECMO group at 90 days (83.2% vs 94.8% vs 95.0%) and 1 year (77.5% vs 89.0% vs 92.5%) (log-rank p < 0.0001). However, in 6-month landmark analyses, survival was similar across groups. Among ECMO recipients, those who died within 6 months had a markedly higher prevalence of pre-transplant dialysis (66.7% vs 34.7%, p < 0.001). The incidence of treated rejection and CAV did not differ significantly among the three groups. Conclusions Direct ECMO bridging is associated with worse early post-transplant outcomes, primarily driven by severe PGD and early mortality, underscoring the need for careful candidate selection. LVAD bridging provided outcomes comparable to non-MCS and may offer a bridge-to-candidacy strategy for selected ECMO patients.