The Short End of the Stick: Access to Lung Transplantation for Short-Statured Patients in the Composite Allocation Score Era.

Short-statured lung transplant (LTx) candidates experience longer waitlist times than taller ones. The new Composite Allocation Score (CAS) includes height to enhance allocation equity. We assessed the impact of CAS on waitlist outcomes for different height groups. We queried a national transplant database for LTx candidates listed from 2021 to 2024, categorized into four height groups: ≤162 cm, 162-170 cm, 170-176.5 cm, >176.5 cm. Competing risk and Cox regression models assessed the impact of height on waitlist outcomes, including an interaction term between height and allocation era to assess effect modification. Of the 9,383 candidates identified, those >176.5 cm had an increased likelihood of transplantation (sHR 1.15) compared to the 170-176.5 cm group, while those ≤162 cm had a lower likelihood (sHR 0.70). The overall likelihood of transplantation was higher in the CAS era (sHR 1.17); The interaction term for height ≤162 cm and CAS era was significant (sHR 1.15), suggesting a modest improvement in access for this group under CAS. Further, candidates ≤162 cm experienced a higher hazard of mortality in the CAS era (HR 1.60). These findings suggest that CAS modestly improves access for the shortest candidates, but refinements are needed to address ongoing inequities in this population.