Left Atrial Dysfunction as an Independent Correlate of Heart Failure Symptoms in Patients With Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction

Abstract

Data regarding the contribution of left atrial (LA) dysfunction to the occurrence of heart failure in patients with severe aortic stenosis (AS) are scarce. The aim of this study was to assess the relationship between LA deformation and symptomatic status in this clinical setting. A total of 361 consecutive patients with severe AS (aortic valve area [AVA] index≤0.6cm2/m2) referred to the echocardiography laboratory were prospectively screened. Two hundred forty-eight patients with preserved left ventricular (LV) ejection fraction (≥50%), in sinus rhythm, and with no more than mild aortic or mitral regurgitation (202 symptomatic and 46 asymptomatic) were enrolled. Asymptomatic status was confirmed by exercise echocardiography or electrocardiography, as clinically indicated. All patients underwent comprehensive echocardiography, including speckle-tracking analysis of LV and LA deformation. No significant differences were found between the two groups regarding age and cardiovascular risk factors. LV ejection fraction and geometric parameters were similar between groups despite higher indexed AVA in asymptomatic patients. In symptomatic patients, brain natriuretic peptide values, average E/e' ratio, and LA size were higher, whereas LV global longitudinal strain and peak LA longitudinal strain and strain rate parameters were lower compared with asymptomatic patients. AVA and peak systolic LA longitudinal strain rate were the only independent correlates of heart failure symptoms (P=.04 and P=.01, respectively). LA systolic strain rate, in addition to AVA, emerged as an independent correlate of the presence of heart failure in patients with severe AS and preserved LV ejection fraction. The echocardiographic evaluation of LA function by speckle-tracking may become useful for risk stratification in patients with asymptomatic AS, but larger prospective studies are needed.