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

Abstract

Restrictive cardiomyopathy (RCM) patients represent a spectrum of disorders. Given the greater emphasis for status exceptions for RCM pts in the new allocation system, we sought to assess whether this change in the allocation policy would affect the wait list and post-transplant outcomes in RCM pts. 89 RCM pts were identified in the UNOS registry that underwent heart transplant (HT) during a 6-mos period immediately before and after UNOS policy change. Comparisons between pt characteristics in the pre (n=62) and post (n=27) policy-change cohorts are reported using standard statistical methods; survival analysis performed using Cox proportional hazards modeling. The waitlist (WL) statuses of the pre pts were 1A (n=34), 1B (n=14), 2 (n=14) while the WL statuses of the post pts were 1 (n=2), 2 (n=13), 3 (n=5), 4 (n=4), 6 (n=2). For the pre and post policy groups, the age, gender, ethnicity, DM status, and ischemic times were similar. The RCM subtype (idiopathic, amyloid, sarcoid, chemo/XRT, and other) distribution was similar for the two groups. Donor age was greater following policy change (40.6 ± 13.0 vs 30.7± 13.0, p=<0.01). Median total days on WL trended towards fewer days for post group (16.0 days vs 33.0 days, p=0.06). IABP utilization was greater for the post policy change group (37% vs 5%, p=<0.01). There was no significant survival difference at 6 month. After UNOS policy change, the 6 months post HT mortality was unchanged in RCM pts as compared to pre-policy change. There was a trend towards shorter wait times and significantly greater utilization of IABP after policy change. Despite the emphasis on status exception for RCM pts, there were fewer overall HT done for RCM.