Waitlist mortality for patients with cardiac allograft vasculopathy under the 2018 OPTN donor heart allocation system

Background: In the 2018 Organ Procurement and Transplantation Network donor heart allocation system, patients listed for re-transplantation due to cardiac allograft vasculopathy (CAV) are assigned to Status 4 unless hemodynamic criteria are met. We aim to examine waitlist outcomes of CAV patients among adult heart transplant candidates.

Methods: We examined waitlist mortality stratified by CAV and waitlist status among adult heart transplant candidates using Scientific Registry of Transplant Recipients data from 10/1/2018-11/1/2023. We analyzed waitlist mortality using Kaplan-Meier curves and doubly-robust Cox regressions adjusted for age, gender, sex, race, and dialysis. We compared CAV to non-CAV patients by initial waitlist status, first status of interest, and time-dependent status.

Results: Of 21,586 listed patients, 368 were listed for CAV. CAV patients were most often listed at Status 4 with lower proportions at Status 3/2/1 compared with non-CAV patients. Status 4 and Status 3 CAV candidates demonstrated higher than expected waitlist mortality compared to non-CAV counterparts (Status 4: HR 0.51, 95% CI 0.31-0.84; p < 0.01; Status 3: HR 0.61, 95% CI 0.23-1.64; p = 0.33) with similar mortality to non-CAV patients in Status 3 and 2, respectively (Status 4: HR 0.80, 95% CI 0.48-1.35; p = 0.4; Status 3: HR 1.07, 95% CI 0.40-2.86; p = 0.89). When stratifying by status tier, CAV waitlist patients ever listed at Status 4 and 3 had a higher probability of death compared to their non-CAV counterparts (Status 4: HR 1.99, 95% CI 1.20-3.31, p < 0.01; Status 3: HR 3.06, 95% CI 1.06-8.87, p = 0.04).

Conclusions: After 2018, CAV patients had a higher risk of waitlist mortality at Status 4 and 3 compared to non-CAV patients. These results suggest that CAV patients are underprioritized in the current allocation system.