Predictors of Favorable Outcome in Patients Bridged to Transplant with Temporary Mechanical Circulatory Support Devices

Purpose Revisions to the US heart allocation system are expected to increase the number of patients bridged to transplant with temporary mechanical circulatory support (TMCS). However, the presence of TMCS at time of transplantation can lead to higher risk of post-transplant mortality. We sought to identify clinical variables associated with favorable post-transplant outcome in patients bridged to transplant with TMCS. Methods We examined data in the ISHLT Thoracic Transplant Registry. We included subjects transplanted between 2005 and 2016 with known use of MCS. Pre-transplant recipient, donor and transplant-specific variables were abstracted. The primary outcome was patient survival at 1 year post transplant in patients bridged with various types of MCS. Cox regression analyses were performed to identify predictors of survival and Cox regression coefficients were used to construct a patient survival calculator. Results There were 6,528 patients bridged to transplant with the following types of MCS: continuous flow LVAD (HeartMate II, HeartMate 3, HeartWare, Jarvik 2000; n=6,206), ECMO (n=134), percutaneous temporary LVAD (P-VAD: Impella 2.5, CP, 5.0, TandomHeart; n=75), surgically implanted temporary LVAD (T-LVAD: CentriMag LVAD; n=38) or BiVAD (T-BiVAD: CentriMag BiVAD; n=75). Kaplan Meier survival among the 5 subgroups is shown in Figure 1A. In a multivariable model, bridging with ECMO or P-VAD was associated with higher risk of mortality. Additional risk factors included older donor age, female/male donor-recipient match, older recipient age, higher recipient body mass index and higher recipient creatinine. We created a calculator that quantifies predicted patient survival at 1 year post-transplant based on donor and recipient characteristics at transplant (Figure 1B). Conclusion The calculator is a novel tool to assist providers in refining the selection of transplant candidates with TMCS with the hopes of improving post-transplant outcomes.