Venous dysfunction in obstructive hypertrophic cardiomyopathies: Results from the 'HCM-Vein' pilot study

Background: Hypertrophic cardiomyopathies (HCM) can be complicated by left ventricular outflow-tract obstruction (LVOTO) responsible for disabling exercise symptoms, a phenomenon influenced by hemodynamic factors including venous return. Methods: We aimed to evaluate venous dysfunction in obstructive HCM patients compared to healthy controls, and to investigate the relationship between venous dysfunction parameters and LVOTO in HCM. This is a clinical, monocentric, prospective, pilot study, in a tertiary care center. We investigated venous function using venous air plethysmography, and endothelial function. Results: Among the 30 symptomatic obstructive HCM patients, 30% (n = 9) presented abnormal venous residual volume fraction (RVFv) which translates in elevated ambulatory venous pressure vs. 0% in the 10 healthy controls (p