Old Donors for Young Heart Transplant Recipients: Clinical Implications of an Emerging Phenomenon

BACKGROUND: Historically, heart transplantation (HTx) has focused on matching recipients with organs from donors of similar or younger age. However, due to the growing shortage of donors, especially in Europe, organs from older donors are being used more frequently. OBJECTIVE: We aimed to evaluate whether transplant matchings with donor older than recipient allocation (DORA) have become more frequent in recent years, if they involved different donor/recipient characteristics, and whether this age mismatch might be associated with less favorable outcomes. METHODS: The temporal evolution of the DORA rate in the Spanish HTx Registry (years 1984-2019, N=8782) was analyzed, and survival was compared in each age-discrepancy group. The effect of DORA on various post-HTx complications was also evaluated. RESULTS: The prevalence of DORA increased from 7% in 1995-1999 to 29% in 2015-2019 (p <0.001). Both donor and recipient ages were significant predictors of increased mortality when considered individually. DORA mismatch was more frequent in urgent than in elective heart transplants, and recipients in the DORA cohort had more favorable characteristics. Even after adjusting for these variables, most DORA mismatch grades were not associated with reduced survival; only extreme mismatches (≥20 years) were associated with increased mortality. The incidence of primary graft failure, acute rejection, infection, or allograft vasculopathy did not differ between groups. CONCLUSIONS: In this extensive real-life registry, receiving a heart from an older donor was generally not associated with increased mortality or complications, although an extreme disparity (≥20 years) might be associated with lower survival.