Evaluating age-based eligibility thresholds for heart re-transplantation – an analysis of the united network for organ sharing database

Background: Risk-adjusted survival after late heart re-transplantation may be comparable to primary transplant, but the efficacy of re-transplantation in older candidates is not established. We evaluated outcomes after heart re-transplantation in recipients > 60 years. Methods: We identified 1026 adult patients undergoing isolated heart re-transplantation between 2003 and 2020 from the United Network for Organ Sharing database. Older recipients (> 60 years, n=177) were compared to younger recipients (≤ 60 years, n=849). Five and ten-year post-transplant survival was estimated using the Kalpan-Meier method and adjusted with multivariable Cox models. Results: Older recipients were more likely to be male and have diabetes or previous malignancies with higher baseline creatinine. They also more frequently required pre-transplant ECMO (11.9% vs. 6.8%, p=0.02) and received re-transplantation due to primary graft failure (13.6% vs. 8.5%, p=0.03). After the transplant, older recipients had a higher incidence of stroke (6.8% vs. 2.6%, p=0.01) and dialysis requirements (20.3% vs. 13.2%) before discharge (both p<0.05), and more frequently died from malignancy-related causes (16.3% vs. 3.9%, p<0.001). After adjustment, recipient age >60 was associated with an increased risk of both 5-year (HR 1.42, 95% CI 1.02-2.01, p=0.04) and 10-year mortality (HR 1.72, 95% CI 1.20-2.45, p=0.003). Restricted cubic spline showed a non-linear relationship between recipient age and 10-year mortality. Conclusions: Heart re-transplantation in recipients > 60 years has inferior outcomes compared to younger recipients. Strict patient selection and close follow-up are warranted to ensure the appropriate utilization of donor hearts and to improve long-term outcomes.