Echocardiographic elastic properties of ascending aorta and their relationship with exercise capacity in patients with non-ischemic dilated cardiomyopathy

Background : Aortic stiffness, an independent predictor of mortality and cardiovascular events, is common among patients affected by non-ischemic dilated cardiomyopathy (NIDC) and heart failure (HF). Methods : A total of 55 patients with diagnosis of NIDC (aged 60 ± 11 years, mean ejection fraction (EF) 35.2% ± 7.7%) admitted consecutively to our department for mild to moderate HF (NYHA class II-III) underwent an echocardiographic study and cardiopulmonary exercise test (CPX). We evaluated elastic properties of ascending aorta, i.e. aortic stiffness and aortic distensibility (mm Hg- 1), derived from ascending aorta systolic and diastolic diameter (mm/m2) measured 3 cm above the valvular plane through 2D-guided M-mode echocardiography. Results : Mean aortic stiffness was 15.63 ± 14.53 and aortic distensibility was 2.61 ± 2.39 mm Hg- 1. Collected parameters at CPX were peak oxygen consumption (pVO2) (ml/kg/min), anaerobic threshold (AT) and the slope of the relation between minute ventilation (VE) and carbon dioxide production (VCO2). Mean pVO2 was 15.4 ± 3.9 ml/kg/min, VE/VCO2 ratio at AT was 36.1 ± 6.1. Functional capacity measured through peak VO2 was found to be directly correlated with aortic distensibility (r = 0.47, p = - 0.0002) and negatively correlated to aortic stiffness index (r = - 0.51, p = - 0.0001). These results were the same at multivariate analysis, corrected by age, hypertension, diabetes mellitus and ejection fraction (respectively r = 0.27, p = 0.008 and r = - 1.75, p = 0.0002). Conclusions : HF patients due to NIDC elastic properties of ascending aorta, evaluated by echocardiography, are correlated with a reduced functional capacity.