UCLA

BACKGROUND: Given ongoing donor shortages, appropriate patient selection for dual-organ transplantation is critical. We evaluated outcomes of heart retransplant with simultaneous kidney transplant (HRT-KT) vs isolated heart retransplant (HRT) across varying levels of renal dysfunction. METHODS: The United Network for Organ Sharing database identified 1189 adult patients undergoing heart retransplantation between 2005 and 2020. Recipients undergoing HRT-KT (n = 251) were compared to those undergoing HRT (n = 938). The primary outcome was 5-year survival; subgroup analyses and multivariable adjustment were performed utilizing the following 3 estimated glomerular filtration (eGFR) groups: <30 ml/min/1.73m2, 30-45 ml/min/1.73m2, and >45 ml/min/1.73m2. RESULTS: HRT-KT recipients were older and had longer waitlist times, longer inter-transplant periods, and lower eGFR levels. HRT-KT recipients were less likely to require pretransplant ventilator (1.2% vs 9.0%, p < 0.001) or ECMO (2.0% vs 8.3%, p < 0.001) support but were more likely to have severe functional limitation (63.4% vs 52.6%, p = 0.001). After retransplantation, HRT-KT recipients had less treated acute rejection (5.2% vs 9.3%, p = 0.02) and more dialysis requirement (29.1% vs 20.2%, p < 0.001) before discharge. Survival at 5-years was 69.1% after HRT and 80.5% after HRT-KT (p < 0.001). After adjustment, HRT-KT was associated with improved 5-year survival among recipients with eGFR <30 ml/min/1.73m2 (HR:0.42, 95% CI: 0.26-0.67) and 30 to 45 ml/min/1.73m2 (HR:0.29, 95% CI 0.13-0.65), but not among those with eGFR>45 ml/min/1.73sm2 (HR 0.68, 95% CI 0.30-1.54). CONCLUSION: Simultaneous kidney transplantation is associated with improved survival following heart retransplantation in patients with eGFR <45 ml/min/1.73m2 and should be strongly considered to optimize organ allocation stewardship.