Exceptions in Pediatric Heart Transplantation: Are We Prioritizing the Right Patients?

In 2018, UNOS changed policies, altering organ distribution patterns. We compare survival in 1A patients with and without exceptions after these policy changes.

Using UNOS, we included Status 1A patients (< 18 years of age) listed for a heart transplant from 2018 to 2025 and categorized them by exception status. Primary outcomes were survival from listing and post-transplant survival. Multivariable Cox regression assessed the independent association between exception status and survival, with a sub-analysis restricted to non-VAD patients.

Of the 3993 patients, 835 (21%) were listed by exceptions. Exception patients were older (7 vs. 2 years, p < 0.001), less often congenital heart disease (CHD) (19% vs. 65%, p < 0.001), and less often on ECMO, VAD, or ventilator support at listing (all p < 0.001). Exception patients had lower waitlist mortality (3.5% vs. 9.8%, p < 0.001), improved survival from listing (log-rank p < 0.0001), and improved post-transplant survival (log-rank p < 0.05). After adjustment for age, diagnosis, and pretransplant mechanical and ventilatory support, exception status was associated with superior survival from waitlist (HR 0.760, 95% CI 0.597-0.968, p = 0.026). In the sub analysis of patients who were not on VAD, exception status shows a trend toward improved waitlist survival (HR 0.843, 95% CI 0.652-1.09, p = 0.19).

Status 1A exception patients have improved waitlist and unadjusted post-transplant survival as compared to standard criteria patients, and are, on average, less acutely ill at listings. These findings highlight heterogeneity within Status 1A and suggest an opportunity to incorporate objective acuity measures into exception review.