Geographic Variation in High-Priority Listing Status Under the New U.S. Heart Allocation Policy

Abstract

Purpose After the implementation of the new heart allocation policy, U.S. transplant centers used more temporary mechanical circulatory support and listed more candidates at high-priority for transplant (Status 1 and 2) than expected. We hoped to study how this intended effect of the policy varies across the country. Methods We performed an observational cohort study of transplant center listing practices before and after the implementation of the new U.S. heart allocation policy using the Scientific Registry of Transplant Recipients. We compared the initial listing data from adult candidates listed between December 2018 and February 2020 (post-policy cohort) to seasonally matched candidates listed between December 2016 and Febraury 2018 (pre-policy cohort). We used mixed-effect logistic regression model to estimate 1) each transplant center's expected and observed rate of high-prioirty status listing and 2) the association of organ procurement organization (OPO) characteristics with the effect of the policy. Results U.S. heart transplant centers (N=96) listed 4,472 adult candidates in the pre-policy period, and 4,498 in the post-policy period. Adjusted for changes in candidate characteristics, the odds of listing a candidate at high-prioirty status at the average transplant cetner was 534% higher than expected (OR: 6.34, 95% CI: 5.08 - 7.91). Centers were more likely to justify post-policy high prioirty listings with intra-aortic balloon pumps (40%) or exceptions (35%). Ninety-one out of 96 (94.8%) centers listed significnatly more candidates at high-priority status than expected, but the excess probability varied widely from 4.8% to 50.4% (IQR: 14.0% - 23.3%). Transplant centers in OPOs in the highest quartile for pre-policy Status 1A transplant rate were more likely to utilize high-prioirty statuses post-policy (OR: 9.70, 95% CI: 6.65 - 14.13) than those in OPOs in the lowest quartile for Status 1A transplant rate (OR: 5.52, 95% CI: 3.89 - 7.84). Conclusion Under the new heart allocation policy, almost all U.S. transplant centers listed more candidates at high prioirty status than expected, but there was substantial variability between centers. Centers in OPOs with a high proportion of Status 1A heart recipients in the pre-policy period were more likely to list candidates at high prioirty Status 1 or 2 after the policy update.