Association of Donor-Recipient Differences in Age, Sex, and Height With Lung Transplant Survival Outcomes: A...

Age, sex, and height are used to calculate predicted total lung capacity (pTLC), a key consideration for lung allocation. However, the association between donor-recipient differences in these individual parameters and survival outcomes remains controversial. The objective of this study was to determine whether differences in age, sex, and height between lung transplant donors and recipients are independently associated with 7-y survival outcomes after adjusting for relevant clinical confounders.

A retrospective cohort study of 1224 lung transplant recipients was conducted at Temple University Health System (2012-2024). The median follow up was 6.22 y (reverse Kaplan-Meier method). The primary analysis treated donor-recipient age difference and height difference as continuous variables in multivariable Cox proportional hazards regression, with restricted cubic splines to evaluate dose-response relationships. Directed analyses (recipient minus donor) were performed to assess whether the direction of the difference was associated with outcomes. Sex mismatch was analyzed as a categorical primary exposure. Sensitivity analyses used prespecified dichotomized thresholds (age >20 y versus ≤20 y; height >6 inches versus ≤6 inches) to facilitate comparison with prior literature. All Cox models were adjusted for recipient age, sex, body mass index, donor age, transplant type, primary diagnosis, transplant era, and ischemic time.

Among 1224 recipients (mean age 64 ± 9 y; 64% male; 414 deaths), neither age difference nor height difference was associated with mortality on continuous analysis: hazard ratio (HR) per 10-y increase in age difference 1.116 (95% confidence interval [CI], 0.872-1.429, P = 0.383); HR per 6-inch increase in height difference 1.174 (95% CI, 0.924-1.492, P = 0.188). Restricted cubic spline analysis confirmed no nonlinear dose-response for either variable. Sex mismatch was not independently associated with mortality (HR, 1.145; 95% CI, 0.928-1.413, P = 0.205). pTLC ratio was similarly nonsignificant (HR per SD, 1.104; 95% CI, 0.955-1.275, P = 0.181). Sensitivity analyses using dichotomized thresholds were consistent with continuous results. Directed height analysis demonstrated numerically higher 7-y survival when the donor was taller than the recipient (67.3% versus 59.0%, P = 0.044). Transplant era was the variable most strongly associated with survival (HR, 0.353, P < 0.001).

Donor-recipient differences in age, sex, and height are not associated with survival outcomes following lung transplantation after multivariable adjustment. These findings suggest potential for broader donor-recipient matching criteria, which could increase organ availability for patients awaiting transplantation. The finding that donor-taller configurations may be associated with greater survival warrants further investigation.