Evolving Changes in Centre-Level Utilization of Longer Distance Donors in Heart Transplantation.

Objectives: This study evaluates changes in centre-level utilization of longer distance donors (LDD) in heart transplantation (HT) before and after the allocation policy change in 2018.

Methods: Adult HT recipients from 2010 to 2023 were identified from the United Network for Organ Sharing registry. Patients were categorized based on donor centre distance and policy change. The Mann-Kendall trend test was utilized for trend analysis. A propensity-matched analysis was performed. Survival analyses were performed using Kaplan-Meier, restricted mean survival time, and multivariable Cox proportional models. Interaction analysis with Bonferroni correction and sensitivity analysis to test the robustness of primary findings were performed.

Results: Among 32 036 recipients from 152 centres, 29 410 from ≤500 miles and 2626 from >500 miles. The mean distance increased from 171 miles to 288 (P < .001) and mean cold ischaemia time from 3.20 to 3.60 h (P < .001) after allocation change. The proportion of recipients with LDD increased from 5.50% in 2010 to 14.00% in 2022, P = .021. In the unmatched cohort, unadjusted 30-day, 1-year, and 5-year survival was comparable between LDD and non-LDD recipients (P > .05). However, risk-adjusted survival in the matched cohort was significantly better with LDD: 30-day (0.60, 0.43-0.82, P = .002), 1-year (0.67, 0.55-0.82, P < .001), and 5-y (0.75, 0.65-0.86, P < .001). Similar findings persisted even after restricted mean survival time analysis. There was a weak correlation between distance and ischaemia time in the matched cohort (r = 0.19).

Conclusions: There has been a substantial increase in the use of LDD following the allocation change. Distance is not a surrogate for ischaemia time. Survival after HT with LDD use is significantly better compared to non-LDD, but further research is warranted.