Subaortic Membranes in Patients With Hereditary Hemorrhagic Telangiectasia and Liver Vascular Malformations

BACKGROUND: Patients with hereditary hemorrhagic telangiectasia have liver vascular malformations that can cause high‐output cardiac failure (HOCF). Known sequelae include pulmonary hypertension, tricuspid regurgitation, and atrial fibrillation. METHODS AND RESULTS: The objectives of this study were to describe the clinical, echocardiographic, and hemodynamic characteristics and prognosis of hereditary hemorrhagic telangiectasia patients with HOCF who were found to have a subaortic membrane (SAoM). A retrospective observational analysis comparing patients with and without SAoM was performed. Among a cohort of patients with HOCF, 9 were found to have a SAoM in the left ventricular outflow tract by echocardiography (all female, mean age 64.8±4.0 years). The SAoM was discrete and located in the left ventricular outflow tract 1.1±0.1 cm below the aortic annular plane. It caused turbulent flow, mild obstruction (peak velocity 2.8±0.2 m/s, peak gradient 32±4 mm Hg), and no more than mild aortic insufficiency. Patients with SAoM (n=9) had higher cardiac output (12.1±1.3 versus 9.3±0.7 L/min, P=0.04) and mean pulmonary artery pressures (36±3 versus 28±2 mm Hg, P=0.03) compared with those without SAoM (n=19) during right heart catheterization. Genetic analysis revealed activin receptor‐like kinase 1 mutations in each of the 8 patients with SAoM who had available test results. The presence of a SAoM was associated with a trend towards higher 5‐year mortality during follow‐up. CONCLUSIONS: SAoM with mild obstruction occurs in patients with hereditary hemorrhagic telangiectasia and HOCF. SAoM was associated with features of more advanced HOCF and poor outcomes.