0091: 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. to assess the factors correlated with LA size in patients with severe AS (aortic valve area (AVA) <1cm 2 or <0.6cm 2 /m 2 ) with preserved left ventricular ejection fraction (LVEF >50%). 80 consecutive patients with isolated severe AS in sinus rhythm (mean age 72±10 years, AVA 0.8±0.2cm 2 , 0.44±0.1cm 2 /m 2 , mean gradient 45±15mmHg, 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/m 2 ), LVEF by the biplane Simpson’s method, LV mas by the ASE M-mode 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. The mean LA volume was 33±12mL/m 2 (extreme values: 13 and 72mL/m 2 ), and dilated LA (defined as LA ≥34ml/m 2 ) was found in 34 cases (43%). In univariate analysis, indexed LA volume was significantly linked to age, hypertension (all, p<0.05), LV mass/m 2 (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) (all, p<0.01), and Sa (r=–0.27, p<0.05). In multivariate analysis, indexed LA volume was independently associated with LV mass/m 2 , E/e’, and PASP (all, p<0.01). Furthermore indexed LA volume was significantly higher in symptomatic patients (n=46) when compared to asymptomatic patients (36±13 vs. 28±10mL/m 2 , p<0.01), with an independent link in a separate multivariate analysis (p<0.01), and was independently correlated to NT-proBNP (Log) in a subgroup of 53 patients who had plasmatic values of this biomarker available (r=0.6, p<0.01). in severe AS with preserved LVEF, LA size is higher in symptomatic patients, and is independently linked to LV remodeling, LV diastolic dysfunction, and PASP, as well as to NT-proBNP a surrogate of increased LV wall stress.