Impact of recipient-donor risk matching on graft survival after lung transplantation

The impact of recipient-donor risk matching on long-term lung transplant outcomes in contemporary practice remains uncertain. As utilization of extended-criteria donors (ECDs) increases, clarifying the relative contributions of recipient risk vs donor marginality is critical.

We performed a retrospective analysis of the United Network for Organ Sharing registry, including adult lung transplants from January 2018 through June 2025. Recipients were classified as low-risk (LRR) or high-risk (HRR) using International Society for Heart and Lung Transplantation-based criteria, and donors were categorized as standard criteria (SCD) or extended criteria (ECD). Transplants were grouped: LRR-SCD, LRR-ECD, HRR-SCD, or HRR-ECD. Primary outcome was graft survival at 1, 3, and 5 years. Multivariable Cox regression and restricted mean survival time (RMST) analyses were performed.

Among 20,635 lung transplants, 4,425 (21.4%) were LRR-SCD, 4,684 (22.7%) LRR-ECD, 5,916 (28.7%) HRR-SCD, and 5,610 (27.2%) HRR-ECD. Composite morbidity increased stepwise from LRR-SCD (28.6%) to HRR-ECD (40.4%) (p < 0.001). Five-year graft survival was similar between LRR-SCD (61.2%) and LRR-ECD (59.4%) groups but significantly lower for HRR-SCD (54.5%) and HRR-ECD (53.4%) (p < 0.001). After adjustment, HRR-SCD (aHR 1.27, 95% CI 1.17-1.38) and HRR-ECD (aHR 1.32, 95% CI 1.22-1.44) had higher graft failure risk vs LRR-SCD, whereas LRR-ECD did not. RMST at 5 years was reduced by 0.27 years in HRR-SCD and 0.33 years in HRR-ECD recipients.

Recipient risk was the dominant determinant of long-term graft survival. LRRs tolerated ECD lungs without survival penalty, whereas HRRs experienced inferior outcomes regardless of donor quality.