Impact of donor‐recipient age‐difference in adolescent heart transplantation

INTRODUCTION: The relationship between donor age and adolescent heart transplant outcomes remains incompletely understood. We aimed to explore the effect of donor-recipient age difference on survival after adolescent heart transplantation. METHODS: The United Network for Organ Sharing database was used to identify 2,855 adolescents aged 10-17 years undergoing isolated primary heart transplantation from 1/1/2000 to 12/31/2022. The primary outcome was 10-year post-transplant survival. Multivariable Cox regression identified predictors of mortality after adjusting for donor and recipient characteristics. A restricted cubic spline assessed the non-linear association between donor-recipient age-difference and the adjusted relative mortality hazard. RESULTS: The median donor-recipient age-difference was +3 (range -13 to +47) years, and 17.7% (n = 504) of recipients had an age- difference > 10 years. Recipients with an age-difference > 10 years had a less favorable pre-transplant profile, including a higher incidence of priority status 1A (81.6%, n = 411 vs. 73.6%, n = 1730; p = .01). The 10-year survival rate was 54.6% (95% confidence interval (CI) 48.8- 60.4) among recipients with a donor-recipient age-difference > 10 years and 66.9% (95% CI: 64.4-69.4) among those with an age-difference ≤10 years. An age-difference > 10 years was an independent predictor of mortality (hazard ratio 1.43, 95% CI: 1.18-1.72, p < .001). Spline analysis demonstrated that the adjusted mortality hazard increased with increasingly positive donor-recipient age-difference and became significantly higher at an age-difference of 11 years. CONCLUSION: A donor-recipient age-difference > 11 years is independently associated with higher long-term mortality after adolescent heart transplantation. This finding may help inform acceptable donor selection practice for adolescent heart transplant candidates.