Post-Heart Transplant Outcomes in Patients with Hypertrophic Cardiomyopathy (HCM) before and after the 2018 UNOS Heart Allocation Policy Change

Purpose Patients with end-stage HCM, the most common genetic cardiovascular condition, often require heart transplant (HT) but there is limited data assessing outcomes. We sought to assess the effect of the 2018 UNOS Heart Allocation policy changes on patients with HCM which increased prioritization for this population. Methods 128 patients with HCM received HT in the year before and after the UNOS policy changes. Pre- (n=65) and post-policy (n=63) cohorts were identified using the UNOS registry. Baseline characteristics were compared using standard statistical analysis. 30- and 180-day outcomes were evaluated using Kaplan Meier survival analysis as well as univariate and multivariate Cox proportional hazards modeling. Results Baseline characteristics were similar for both groups, but differed in median [IQR] distance (nm) from donor and treatment center (pre: 91 [17, 253]; post: 245 [100.5, 393]; p=0.002) and median PA pressure (mm/Hg) at registration (pre: 38 [30, 49.2]; post: 45 [31, 58], p=0.036). Donor characteristics differed in mean BMI (pre: 26.1 (SD 7.2); post: 28.9 [SD 7.2]). Pre- and post-policy 30-day survival was 100% (CI 100%, 100%) and 95% (CI 90%, 100%) respectively. Pre- and post- 180-day survival was 94% (CI 88%, 100%) and 90% (CI 83%, 98%). Cox univariate hazard ratio (HR) following the UNOS change was 1.62 (CI 0.46, 5.73, p=0.5). Multivariate Cox proportional HR adjusted for recipient age, donor age, serum creatinine, total bilirubin, ischemic time, pre-transplant dialysis, ventilator and ECMO status was 1.54 (CI 0.39, 6.09, p=0.5). Conclusion UNOS policy changes did not adversely affect survival at 30 and 180 days for patients with HCM receiving HT. Additional research is needed to evaluate the effects these policy changes have on patients with HCM.