Comparison of Six-Month Outcomes in Hypertrophic Cardiomyopathy Patients before and after UNOS Allocation System Change

Abstract

HCM patients may have increased waitlist (WL) mortality. Given the recent change in prioritizing patients with restrictive and hypertrophic cardiomyopathy requiring mechanical support, we sought to assess whether the policy change would affect the waitlist and post-transplant outcomes in HCM pts. 59 pts were identified in UNOS registry that underwent heart transplant (HT) with a diagnosis of HCM during a 6-month period immediately before and after the UNOS policy change. Comparisons between pt characteristics in the pre (n=43) and post (n=16) policy-change cohorts are reported using standard statistical methods; survival analysis performed using Cox proportional hazards modeling. The WL statuses of the pre-policy change pts were 1A (n=22), 1B (n=11), 2 (n=10) while the WL statuses of the post pts were 1 (n=2), 2 (n=7), 3 (n=1), 4 (n=6). For both groups, the age, donor age, gender, ethnicity, DM status, and ischemic times were similar. The median wait list time was decreased following the policy change (24.5 vs. 43 days, p=0.01). There was greater use of IABP following the allocation system change (31% vs. 5%, p=0.01). There was a trend toward worse post-HT survival in HCM following the policy change (p=0.06). The policy change significantly decreased waiting times for HCM pts on the HT list with a trend towards increased mortality with decreased rates of transplant. Further study is warranted to understand the long-term implications of this policy change.