Heart Transplant Outcomes and Trends in Pre-Transplant Impella Use

Abstract

<h3>Purpose</h3> Temporary mechanical circulatory support devices are being used at increased frequency as a bridge to heart transplantation (HT), particularly with changes in the US heart allocation policy. We sought to understand the implications of pre-transplant Impella utilization, as well as trends in use. <h3>Methods</h3> 28,989 HT recipients were identified from the UNOS Registry between 1/2010 to 6/2021, of which 394 had Impella as bridge to transplant. Baseline clinical characteristics were compared using Mann-Whitney U test and Chi-square test. Survival analysis was censored at 36 months using Kaplan-Meier analysis. Univariate and multivariate Cox proportional hazards regression analysis was adjusted for age, gender, ethnicity, ischemic time, dialysis use, waiting time, HLA mismatch, and life support use. <h3>Results</h3> Pre-HT Impella recipients were more likely to be male (80.7 vs 73.4%, p=0.001), require ventilator support (6.1 vs 1.5%, p<0.001), require pre-HT dialysis (10.2 vs 4.4%, p<0.001) with shorter waiting time (13.0 vs 82 days, p<0.001), longer ischemic time (p=0.01) and elevated pulmonary arterial pressures (p<0.001). Additionally, pre-HT Impella recipients were less likely to have had prior cardiac surgery (13.5 vs 23.7%, p<0.001). There was no survival difference post-HT with Impella use (log rank, p=0.882; Figure 1A). Furthermore, Impella use was not a significant predictor of mortality on both univariate (HR: 1.02 [0.74-1.40] and multivariate analysis (HR: 0.91 [0.65-1.27]). Overall, a trend in increasing pre-HT impella use was observed over time (Figure 1B) <h3>Conclusion</h3> Pre-HT Impella use was associated with acceptable post-HT outcomes despite increased patient acuity (i.e. dialysis, ventilator need, elevated filling pressures). Further study is warranted to enhance pre-HT optimization.