Outcomes Of IABP Vs Impella As A Bridge To Cardiac Transplantation - Analysis Of National United Network For Organ Sharing Database

Abstract

<h3>Introduction</h3> Temporary mechanical circulatory support technology has advanced vastly in the last decade. United Network for Organ Sharing (UNOS) heart transplant allocation system was updated in 2018 to accommodate the new Era. Among patients requiring temporary mechanical circulatory support as a bridge to transplantation, device choice relies on patient, practitioner, and institutional factors. To date, there is limited outcome data to contrast the different mechanical circulatory support platforms. <h3>Objective</h3> We aim to compare heart transplant survival in those bridged with intra-aortic balloon pump (IABP) vs Impella mechanical support. <h3>Methods</h3> Using the national UNOS database, we studied heart transplantation recipients listed on the new UNOS allocation system (oct 18^th 2018) and then compared survival of those bridged with IABP vs Impella to transplantation as status 2. The last date of follow up was Sep 4^th 2020. Cohort demographics, serum biochemistry, hemodynamic measurements, and organ support interventions were collected. Wilcoxon-Mann-Whitney test was used for continuous variables, Chi-square test for categorical variables, and Log-rank test for survival analysis. <h3>Results</h3> A total of 1721 patients (1524 IABP, 197 Impella) met our criteria, in whom, there was no difference between IABP vs Impella groups in age, BMI, or waiting list time (Table 1). We found that Impella was used more often in males (74% vs 88%, p <0.01) and Hispanics (9% vs 15% p <0.01). Clinical data are summarized in Table 1. Impella was associated with more mechanical ventilation (4 vs 16%, p <0.01), dialysis (3 vs 10%, p <0.01), and vasoactive medication support (79 vs 89%). Plasma free hemoglobin > 50 mg/dL was noted in 13.3% of the Impella group. Median survival (figure 1) was similar between IABP vs Impella (181 vs 183 days, p=0.92). <h3>Conclusion</h3> There was no observed difference in waiting time nor post-transplant survival between IABP vs Impella groups, however, the latter group was in more critical condition, and from that perspective, Impella seems to be an effective platform to bridge higher acuity status 2 patients.