Abstract
INTRODUCTION: Donor age is a key determinant of liver transplant (LT) outcomes, but its impact varies across recipient age groups. Specific donor age thresholds associated with excess risk remain undefined. METHODS: Using data from the Scientific Registry of Transplant Recipients (2011-2021; follow-up through 2024), we analyzed first-time, single-organ LT recipients. Donors and recipients were stratified by age. Outcomes included patient, graft, and death-censored graft survival. Multivariable Cox regression models adjusted for liver disease severity, comorbidities, graft type, and transplant year were used to identify donor age thresholds associated with increased risk in each recipient age group. RESULTS: Among 70 078 recipients (median age, 57 years), mean donor age rose from 39.6 to 40.9 years (p = .004), while recipient age increased from 50.7 to 51.9 years (p = .003). Donor age ≥50 years was associated with a sixfold increase in mortality in pediatric recipients (aHR, 6.48; 95% CI, 1.92-21.83; p = .003). For adults aged 18.1-30 years, excess mortality and graft loss were observed with donors >55 years (aHRs >2.5). In recipients aged 40.1-60 years, risk increased progressively with donor age. Among recipients ≥65 years, donor age was not significantly associated with outcomes. These thresholds were consistent across outcomes and robust in sensitivity analyses. CONCLUSIONS: This is the first national study to define recipient age-specific donor age thresholds associated with post-LT risk. These findings support the development of age-informed allocation strategies and call for a reassessment of organ discard practices as donor and recipient ages continue to rise.