UNOS Registry Study: The Impact of Preoperative Mechanical Circulatory Support Devices to Heart Transplant Outcomes in over 78,000 Patients

PURPOSE Preoptimizing the hemodynamics and volume status prior to heart transplant is essential for the outcome. Temporary mechanical circulatory support (MCS) has been expanding especially after recent changes to the UNOS donor heart allocation criteria. The aim of our study is to evaluate the incidence of various MCS device use and outcomes of preoperative MCS to heart transplantation. METHODS We performed a retrospective analysis using the UNOS Resistry of all adult heart transplant recipients from 1997 to 2017 comparing various MCS device regarding days to discharge, hospital survival and 2 year survival rates. Patient who did not have MCS preoperatively were analyzed as base line survival. A multivariate Cox proportional hazard analysis was performed, adjusted for recipient hemodynamics, age, and various MCS devices. Kaplan Meier survival analysis and log-rank test were used to compare survival. RESULTS There were 78,181 patient included in our study. Devices used for bridging included HeartMate II (N = 6,053), HVAD (N = 2,195), Syncardia (N = 322), Impella (N = 72), TandemHeart (N = 18), CentriMag (N = 153), ECMO (N = 1,513), and IABP (N = 2,509). Bridging with HM2 (HR 0.74, p<0.001) and HVAD (HR 0.82, p<0.001) were independent predictors of improved 5-year survival compared to the non MCS patients. Syncardia (HR 1.59, p<0.001) and ECMO (HR 1.68, p<0.001) had poorer survival. IABP (p=0.45), TandemHeart p=0.60), and CentriMag (p=0.19) had no impact on survival. Kaplan meier survival analysis corroborates these findings. CONCLUSION Our study showed BTT MCS can provide comparable clinical outcomes to primary OHT. However, ECMO was independent predictors of mortality after transplantion. This finding may guide the decision on heart transplant candidacy and timing of heart transplant.