Abstract 18488: The Impact of Mechanical Circulatory Support Type for Bridge-to-Transplantation on Post-transplant Prognosis: An Analysis of the United Network for Organ Sharing (UNOS)

Abstract

Purpose Mechanical circulatory support through left ventricular assist devices (LVAD) and extracorporeal membrane oxygenators (ECMO) is a reliable and useful support for bridge-to-transplantation (BTT) therapy. The purpose of this study was to investigate the impact of mechanical circulatory support on post-transplant prognosis and its changes during recent years. Methods The United Network for Organ Sharing (UNOS) database was used to identify adults patients (≥18 yrs) undergoing orthotopic heart transplantation (OHT) from 1987 to 2010. The cohort was separated into 5 groups according to the era of OHT: before '91, '92 to '96, '97 to '01, '02 to '06, and after '07. We compared two-year post-OHT survival of patients initially supported by an LVAD only and those with biventricular mechanical circulatory support at the time of OHT. Patients who required the additional use of ECMO during LVAD support and those with urgent assist device placement for right and left ventricule were considered as biventricular support group. Results A total of 17257 patients underwent OHT under mechanical circulatory support. Post-transplant mortality of patients with biventricular support was worse compared to patients with LVAD support alone after 1997 (Biventricular vs. LVAD alone, ’97-‘01, 56.3 vs. 77.0%, p=0.014; ’02-’06, 58.6% vs. 83.7%, p<0.001; ’07- 60.9% vs. 87.7%, p<0.001, respectively). Comparison among 5 groups by time period showed that post-transplant mortality of patients with LVAD support showed significant improvement after 1997. The mortality of patients with biventricular support, however, showed no improvement over time (Figure). Conclusion Post-transplant mortality in patients with LVAD BTT support improved significantly during the recent era of OHT. Patients undergoing biventricular support prior to OHT, especially those with hemodynamic instability requiring urgent ECMO placement on top of LVAD support remain to have poor outcome in any era of OHT.