Long-Term Effects of Left Ventricular Assist Device Therapy on Pulmonary Vascular Resistance in Patients Bridged to Heart Transplant

Background: Elevated pulmonary vascular resistance (PVR) is a relative contraindication to cardiac transplantation. Bridge-to-transplant with LVAD may reduce PVR, though its efficacy and long-term outcomes post-transplant are unknown. Methods & Results: Retrospective review was performed with selection of patients who received LVADs for BTT indication from May 2008 to November 2016. Subjects were divided into two groups based on pre-VAD hemodynamics: PVR ≥ 3 and PVR<3. 83 BTT patients received HeartMate II (n=53) or HeartWare (n=32) with a mean PVR of 2.7 ± 1.6 Woods units (W.U). Thirty-five patients (42%) had PVR ≥ 3. A total of 44 patients (53%) successfully underwent OHT. Pre-implant PVR did not affect likelihood of undergoing OHT (49% vs 51%, p=ns). VAD support as BTT successfully reduced PVR across the entire cohort (2.7 ± 1.6 to 1.2 ± 0.6 W.U. p<0.01). HMII and HVAD were equally effective in decreasing post-OHT PVR in the long-term (1.2 ± 0.5 vs 1.3 ± 0.5 W.U. p=0.5). Having PVR>3 pre-VAD did not influence post-OHT PVR, both at immediate post-operative (1.2 ± 0.5 vs 1.2 ± 0.6 W.U. p=0.8) and at 2-years follow-up time points (1.2 ± 0.4 vs. 1.4 ± 0.6 W.U. p=0.2). Kaplan Meier analysis demonstrated similar survival post-OHT at 30 days (88% vs. 96%) and 6 years (62% vs. 74%, p=0.2), and similar incidence of moderate or greater RV failure post– OHT (p=0.4). Conclusion: VAD support successfully reduces PVR among BTT patients, and does not appear to increase the incidence of adverse events or reduce survival.