Global longitudinal strain in relation to the severity of aortic stenosis: A two-dimensional speckle-tracking study

Background: Global longitudinal strain (GLS) measured by two-dimensional speckle tracking imaging (2D-STI) has been shown to be useful for assessing subtle change in left ventricular function in severe aortic stenosis (AS) patients with preserved left ventricular ejection fraction (LVEF). However, there is little information about the relation between the progression of AS and changes in GLS. The aim of this study was to evaluate the relation between the severity of valve stenosis and GLS measured by 2D-STI in AS patients with normal LVEF. Methods: We studied 113 AS patients (age, 73.3 ± 8.8 years; male, 38%; aortic valve area (AVA), 1.0 ± 0.3 cm ²; mean pressure gradient (PG), 33.8 ± 22.1 mmHg) with normal LVEF (≥50%) but without overt coronary artery disease. Patients were stratified into three groups (mild, moderate and severe AS), and the clinical characteristics and echocardiographic findings were compared among the groups. Using dedicated software, we measured GLS in the apical four-chamber view. Results: LVEF was not significantly different among the three groups. However GLS showed significant differences in GLS among the three groups (mild: 17.1 ± 3.0%, moderate: 16.4 ± 3.0% and severe: 14.5 ± 3.9%, ANOVA P = 0.003). GLS was significantly correlated with AVA, mean PG, LVEF, LV mass index and early diastolic mitral annular velocity (e'). In multiple stepwise regression analysis, mean PG, LVEF and hypertension were independently associated with GLS (R ²= 0.247, P = 0.0001). Conclusions: Despite unchanged LVEF, GLS gradually decreased as severity of AS increases. GLS measured by 2D-STI might be useful to assess subtle changes in LV function in AS patients.