Predictive Accuracy Of Heartmate 3 Risk Score After Heart Transplant Allocation Change

• Published in: Journal of cardiac failure 2024-01, Vol.30 (1), p.172-173
• Main Authors: Vincent, Justin, Yang, Bin Q., Deych, Elena, Vader, Justin
• Format: Article
• Language: English
• ISSN: 1071-9164; 1532-8414
• DOI: 10.1016/j.cardfail.2023.10.136

The HeartMate 3 Risk Score (HM3RS) is a tool derived and validated from the MOMENTUM 3 clinical trial population to predict mortality after left ventricular assist device (LVAD) implantation. However, the UNOS adult heart allocation policy was revised in October 2018, resulting in a drastic decrease in bridge-to-transplant LVAD use. In this study, we assessed the predictive accuracy of HM3RS at a single institution, both before and after the 2018 UNOS allocation policy change. We retrospectively analyzed all adult patients who received a HeartMate 3 (HM3) at Washington University School of Medicine in St. Louis between 2015 - 2021. We calculated the HM3RS for each patient, categorized as low (2.48). The primary outcome was mortality at 1 and 2 years, stratified before and after the date of the UNOS allocation policy change (10/1/2018). A total of 178 HM3 recipients were included, 61 of whom received a HM3 before 10/1/2018. Patient demographics were similar, although LVAD recipients were more likely to be INTERMACS 1 or 2 post-allocation system change compared to pre-allocation system change (78% vs. 47%). HM3RS accurately predicted 1- and 2-year mortality pre-10/2018 with AUC 0.76 and 0.71, respectively, comparable to the original study. However, post-allocation system change, HM3RS performed much worse, with AUC 0.56 at 1 year and 0.40 at 2 years, despite similar patient outcomes (Figure 1). HM3RS accurately predicted mortality in a real-world population before the 2018 UNOS allocation change although it had mediocre performance after. This score may need recalibration to better assess risk for current and future patients undergoing HM3 implantation.