Outcomes in Heart Transplant (HT) in Patients Receiving Inotropes Following UNOS Heart Allocation Policy Changes

Abstract

<h3>Purpose</h3> The 2018 UNOS Heart Allocation policy changes aimed to improve stratification in patients receiving heart transplant. Patients receiving inotropes who were classified as status 1A were re-classified as status 3 following the changes. We sought to assess the effect of the 2018 UNOS Heart Allocation policy changes on patients receiving inotropes. <h3>Methods</h3> 1569 patients who required inotropes received HT in the year before and after the UNOS policy changes. Pre- (n=831) and post-policy (n=738) cohorts were identified using the UNOS registry. Baseline characteristics were compared using standard statistical analysis. 180-day outcomes were evaluated using Kaplan Meier survival analysis as well as univariate and multivariate Cox proportional hazards modeling. <h3>Results</h3> Baseline characteristics were similar for both groups regarding age, gender, ethnicity, diabetes status, smoking history, non-transplant cardiac surgery history, ventilator use, serum creatinine, PA mean pressure, and cardiac output but differed in IABP use at transplant (pre: 10%, post: 48.5%, p<0.001) and median ischemic time at less than 1, 1-2, 2-3, and greater than 4 hours, tested as a group (p<0.001). Pre-and post-policy 180-day survival was not statistically different (p=0.7391). Cox univariate hazard ratio (HR) following the UNOS change was 1.07 (CI 0.71, 1.63, p=0.739). Multivariate Cox proportional HR adjusted for age, sex, ethnicity, type 2 DM status, HLA mismatch level, total days on waitlist, and ischemic time was 1.016 (CI 0.651, 1.585, p=0.944). <h3>Conclusion</h3> UNOS policy changes were not shown to affect HT survival 180 days for patients receiving inotropes prior to transplant, however mean ischemic time and days on waiting list were increased, as well as IABP use. Further research is warranted to determine if these factors will affect patient mortality moving forward.