Microaxial Left Ventricular Assist Device Versus Intraaortic Balloon Pump as a Bridge to Transplant

BACKGROUND Heart transplantation (HTx) candidates supported by Impella (Abiomed, Danvers, MA) or intraaortic balloon pump (IABP), who demonstrate evidence of cardiogenic shock, may qualify for waitlist status 2 without exception under the new donor heart allocation system. However limited data comparing Impella versus IABP as a bridge to HTx exist. METHODS The United Network for Organ Sharing database was queried for adults listed and/or transplanted between January 2014 and February 2020. Temporal trends regarding Impella and IABP use were analyzed using the Royston trend test and chi(2) test. Waitlist mortality was examined using Fine-Gray competing risks analysis. Post-HTx 180-day survival was analyzed using the Kaplan-Meier method and Cox proportional hazards models. RESULTS Impella use increased from 0.2% in 2014 to 2.6% in 2020 (P < .01) and from 0.4% to 2.2% (P < .01) under the new allocation system. IABP use increased from 4.9% in 2014 to 27.6% in 2020 (P < .01) and from 6.7% to 26.6% (P < .01) under the new allocation system. Post-HTx survival was similar between groups (adjusted hazard ratio, 0.82; 95% CI, 0.38-1.78) despite more preoperative ventilation (3.6% vs 1.1%, P [.01) and higher model for end-stage liver disease excluding international normalized ratio scores (12.4 vs 9.5, P < .01) among Impella-supported recipients. Under the new system Impella-supported candidates were at higher risk of waitlist delisting compared with IABP-supported candidates (subhazard ratio, 2.42; 95% CI, 1.19-4.92). CONCLUSIONS Post-HTx survival is comparable between Impella-supported and IABP-supported recipients despite worse preoperative profiles among Impella-supported recipients. Higher risk of waitlist delisting among Impellasupported candidates under the new allocation system requires close attention. (C) 2022 by The Society of Thoracic Surgeons

Automated summary

This study compared the effectiveness of Impella and IABP as bridges to heart transplantation and found no significant differences in post-transplant survival rates between the two groups. However, Impella-supported candidates had worse preoperative profiles and were more likely to be delisted from the waitlist under the new allocation system.