The Waiting Game: Waitlist Times And Outcomes For Highly Sensitized Patients In The New Heart Transplant Allocation System

PurposeIn 2018, United Network of Organ Sharing (UNOS) changed the heart allocation system to better stratify higher acuity patients and provide more equitable geographic distribution. However, they did not prioritize recipient allosensitization which can be a barrier to organ access. We analyzed outcomes based on sensitization in the modern era and the impact of the new allocation system on sensitized patients.MethodsUNOS data from 3/31/2015-6/12/2020 was analyzed. Multi-organ transplants were excluded. Recipient, donor, and transplant characteristics were analyzed. Patients were stratified by cPRA level 0, 1-49, 50-79, and ≥ 80. Waitlist days prior to transplant, survival, and treated rejection pre and post allocation system change were analyzed. Survival was estimated using Kaplan-Meier methods and the log-rank test.ResultsTotal of 10598 patients were included and evaluated by cPRA (Table). Patients with higher cPRA were more likely to be younger, African American, and female. Higher cPRA patients weighed less and were more likely to have non-ischemic cardiomyopathy, congenital disease, or be a retransplant. Waitlist days were significantly lower in the new allocation system for cPRA groups 0, 1-49, and 50-79 (p<0.0001) and there was a trend toward fewer waitlist days for cPRA ≥ 80 (p=0.062). Treated rejection during the transplant hospitalization and in the first year was significantly higher as cPRA increased (p<0.0001). However, when compared pre- and post-allocation change, there was no significant difference in long term survival across cPRA groups (p=0.531).ConclusionThe new heart allocation system did not discriminate against sensitization, but rather facilitated a reduction in wait time for all but the most highly sensitized recipients. This may relate to increased access to appropriately matched donor organs through broader geographic sharing, but further investigation is needed. In 2018, United Network of Organ Sharing (UNOS) changed the heart allocation system to better stratify higher acuity patients and provide more equitable geographic distribution. However, they did not prioritize recipient allosensitization which can be a barrier to organ access. We analyzed outcomes based on sensitization in the modern era and the impact of the new allocation system on sensitized patients. UNOS data from 3/31/2015-6/12/2020 was analyzed. Multi-organ transplants were excluded. Recipient, donor, and transplant characteristics were analyzed. Patients were stratified by cPRA level 0, 1-49, 50-79, and ≥ 80. Waitlist days prior to transplant, survival, and treated rejection pre and post allocation system change were analyzed. Survival was estimated using Kaplan-Meier methods and the log-rank test. Total of 10598 patients were included and evaluated by cPRA (Table). Patients with higher cPRA were more likely to be younger, African American, and female. Higher cPRA patients weighed less and were more likely to have non-ischemic cardiomyopathy, congenital disease, or be a retransplant. Waitlist days were significantly lower in the new allocation system for cPRA groups 0, 1-49, and 50-79 (p<0.0001) and there was a trend toward fewer waitlist days for cPRA ≥ 80 (p=0.062). Treated rejection during the transplant hospitalization and in the first year was significantly higher as cPRA increased (p<0.0001). However, when compared pre- and post-allocation change, there was no significant difference in long term survival across cPRA groups (p=0.531). The new heart allocation system did not discriminate against sensitization, but rather facilitated a reduction in wait time for all but the most highly sensitized recipients. This may relate to increased access to appropriately matched donor organs through broader geographic sharing, but further investigation is needed.