Tissue Velocities and Myocardial Deformation in Asymptomatic and Symptomatic Aortic Stenosis

Abstract

Background: Assessment of myocardial longitudinal function has proved to be a sensitive marker of deteriorating myocardial function in aortic stenosis, demonstrated by both color Doppler tissue imaging and recently by two-dimensional speckle-tracking echocardiography. The aim of this study was to compare velocity (color Doppler tissue imaging) and deformation (two-dimensional speckle-tracking echocardiography) in relation to global and regional longitudinal function in asymptomatic and severe symptomatic aortic stenosis.

Methods: In a cross-sectional design, 231 patients with aortic stenosis were divided into four groups: asymptomatic moderate aortic stenosis (aortic valve area, 1.0-1.5 cm(2); n = 38), asymptomatic severe aortic stenosis (aortic valve area < 1.0 cm(2); n = 66), and symptomatic severe aortic stenosis with preserved (n = 68) and reduced (<50%) left ventricular ejection fraction (n = 59).

Results: Among all global (peak systolic s', diastolic e' and a', longitudinal displacement, and global longitudinal strain and strain rate) and regional longitudinal (basal, middle, and apical longitudinal strain and strain rate) parameters, only diastolic e', longitudinal displacement, and basal longitudinal strain (BLS) remained significantly associated with symptomatic status, independent of age, gender, heart rate, aortic valve area, stroke volume index, left ventricular mass index, left atrial volume index, and tricuspid annular systolic plane excursion. Furthermore, in a model with the aforementioned parameters, including e', longitudinal displacement, and BLS, only BLS remained significantly associated with symptomatic status in the entire study population (BLS per one-unit decrease: odds ratio, 1.23; 95% CI, 1.04-1.46; P = .017). Furthermore, patients with BLS < 13% were more likely to be symptomatic (odds ratio, 4.97; 95% CI, 2.6-9.4; P < .001), and no patients with asymptomatic severe aortic stenosis with BLS ≥ 13% were admitted with myocardial infarction or heart failure during follow-up of 1,462 days.

Conclusions: Among the many echocardiographic measures of longitudinal velocity and deformation, BLS has the strongest association with symptomatic status in aortic stenosis, and BLS < 13% is related to adverse outcomes in severe asymptomatic aortic stenosis.

Keywords: Aortic stenosis; Regional longitudinal function; Speckle-tracking; Tissue Doppler.