Evolving changes in center-level utilization of longer distance donors in heart transplantation

OBJECTIVES This study evaluates changes in center-level utilization of longer distance donors (LDD) in heart transplantation (HT) before and after allocation policy change in 2018. METHODS Adult HT recipients from 2010–2023 were identified from the United Network for Organ Sharing registry. Patients were categorized based on donor center 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 centers, 29,410 from ≤500 miles and 2,626 from >500 miles. The mean distance increased from 171 miles to 288 (p < 0.001) and mean cold ischaemia time from 3.20 h to 3.60 h (p < 0.001) after allocation change. The proportion of recipients with LDD increased from 5.50% in 2010 to 14.00% in 2022, p = 0.021. In unmatched cohort, unadjusted 30-d, 1-y, and 5-y survival was comparable between LDD and non-LDD recipients (p > 0.05). However, risk adjusted survival in matched cohort was significantly better with LDD: 30-d (0.60, 0.43–0.82, p = 0.002), 1-y (0.67, 0.55–0.82, p < 0.001), and 5-y (0.75, 0.65–0.86, p < 0.001). Similar findings persisted even after restricted mean survival time analysis. There was a weak correlation between distance and ischaemia time in matched cohort (r = 0.19). CONCLUSIONS There has been a substantial increase in the use of longer distance donors following the allocation change. Distance is not a surrogate of ischaemia time. Survival after heart transplantation with LDD use is significantly better compared to non-LDD but further research is warranted.