Factors associated with left atrial size in severe aortic stenosis

Abstract

Left atrial (LA) enlargement is associated with a poorer prognosis in several diseases, including aortic stenosis (AS). However, apart diastolic dysfunction, the main determinants of LA size in the setting of aortic stenosis are poorly understood. Objective To assess the factors correlated with LA size in patients with severe AS [aortic valve area (AVA) 50%). Methods Eighty consecutive patients with isolated severe AS in sinus rhythm (mean age 72 ± 10 years, 47.5% women, AVA 0.8 ± 0.2 cm2, 0.44 ± 0.1 cm2/m2, mean gradient 45 ± 15 mmHg, LVEF 68 ± 10%) underwent a comprehensive transthoracic Doppler echocardiography including the measurement of the LA volume at end-systole by the biplane area-length method (from the 4-and 2-apical chamber views), indexed to body surface area (ml/m2). LV mass was measured by ASE M-mode method, LVEF by the biplane Simpson's method, and early (e′), late diastolic (a′), and systolic (Sa) mitral annular Doppler tissue velocities were calculated as an average of the septal and lateral values. Results The mean LA volume was 33 ± 12 ml/m2 (extreme values: 13 and 72 ml/m2), and dilated LA (defined as LA ≥ 34 ml/m2) was found in 34 cases (43%). In univariate analysis, indexed LA volume was significantly linked to age (P = 0.05), hypertension (P = 0.02), LV mass/m2 (r = 0.5), pulmonary artery systolic pressure (PASP) (r = 0.55), mitral E/A ratio (r = 0.32), E/e′ ratio (r = 0.46), a′ (r = 0.4), LVEF (r = –0.3), and Sa (r = –0.27) (all, P Conclusion In severe AS with preserved LVEF, LA size is higher in symptomatic patients, and is independently linked to LV remodeling, LV diastolic function, and PASP, as well as to NT-proBNP a surrogate of increased LV wall stress.