Assisting the Heart to Assist the Lungs: LVAD Support in Restrictive Physiology and Pulmonary Hypertension

Abstract

Introduction Pulmonary hypertension (PH) is a risk factor for mortality after heart transplantation (HTx). We present a case of treatment of post-capillary PH in a small pediatric patient with restrictive physiology using continuous flow ventricular assist device (VAD) support to achieve candidacy for HTx. Case Report A 4.5 year old female (0.57m2) with a history of acute myeloid leukemia and anthracycline chemotherapy in infancy developed mildly depressed left ventricular (LV) function at 2 years of age. Hemodynamic catheterization (cath) showed pre- and post-capillary PH secondary to LV diastolic dysfunction and restrictive physiology (Table). She was cautiously initiated on PDE5 inhibitor therapy (sildenafil) while maintaining LV reverse remodeling therapies. Her heart failure (HF) symptoms and biventricular systolic function worsened over the subsequent 2 years. Subsequent caths showed increasing PVRi, which was responsive to 100% FiO2 and inhaled nitric oxide (iNO), but also accompanied by increase in LV end-diastolic pressures (LVEDP). She was transitioned to endothelin receptor antagonist therapy (bosentan), but continued to worsen clinically, requiring initiation of milrinone. Due to her underlying restrictive physiology leading to worsening PH and severely depressed right ventricular (RV) function, a HeartWare HVAD (cannulation LV to Aorta) was implanted to allow aggressive optimization of PH therapies with simultaneous LV decompression. This enabled up-titration of bosentan as well as re-addition of sildenafil. After PH therapies including VAD implantation, PVRi decreased from a high of 10.7 WU.m2 to 4.7 WU.m2, and marked decline of LVEDP from 22 mmHg pre-VAD to 5 mmHg. She underwent HTx 6 months after VAD implantation, and was discharged home 12 days post-HTx on sildenafil. Summary VAD support in tandem with optimal PH therapies is a feasible strategy to treat post-capillary PH, optimize pulmonary vasculature to reduce RV dysfunction, and enable a successful bridge to HTx.