Effect of pulmonary hypertension on transplant outcomes in patients with ventricular assist devices

Abstract Background Although extremely-high pulmonary vascular resistance (PVR) is a relative contraindication for heart transplantation (HTx), recent data with continuous-flow left ventricular assist devices (LVADs) indicate HTx outcomes may be different when high PVR is managed with LVAD. This study aims to clarify the contemporary association between PVR at HTx and post-transplant survival in LVAD vs. non-LVAD cohorts. Methods We reviewed the United Network for Organ Sharing (UNOS) registry for adults transplanted from 2008 to 2015. In those with continuous-flow LVADs and those with no VADs at HTx, we grouped patients by low PVR (PVR =6) groups. Adjusted hazard ratios (aHRs) for death after HTx were calculated by Cox regression. Results The non-LVAD cohort included 6270 patients (4385 in low, 1643 in intermediate, and 242 in high PVR), while the LVAD cohort included 4111 patients (3227 in low, 798 in intermediate, and 86 in high PVR). The high PVR LVAD group had the worst survival, which was not significant, likely to low power (p=0.300). In non-LVAD, the aHR for death was 1.047 (95%CI 1.010-1.088), while in LVAD, it was 1.063 (95%CI 1.010-1.119). Cubic spline analysis demonstrated non-linear associations between PVR and aHR, especially in the LVAD cohort. Conclusions There was no significant evidence to conclude the effect of pre-transplant PVR on post-transplant survival is higher in LVAD vs. non-LVAD patients, based on analysis of the UNOS database. However, further investigations are indicated to clarify heart transplant candidacy in those with extremely-high PVR even after LVAD.