Strain Imaging with a Bull's-Eye Map for Detecting Significant Coronary Stenosis during Dobutamine Stress Echocardiography

Abstract

Accurate visual assessment of wall motion during dobutamine stress echocardiography (DSE) requires expertise; strain stress echocardiography thus has potential for the objective and reliable evaluation of stress-induced wall motion abnormalities. The aim of this study was to test the hypothesis that strain imaging also requires expertise. Diagnostic accuracy for significant coronary artery disease was compared between visual and strain analysis with a bull's-eye map, and the effect of expertise on readers' accuracy during DSE was determined. Thirty-seven patients who underwent both DSE and coronary angiography within 6months were retrospectively selected. Three experts and two fellows performed visual and two-dimensional speckle-tracking analysis using vendor-dependent (GE) software in three apical views. A bull's-eye map of longitudinal strain and a postsystolic shortening map were generated at baseline and peak stress. Significant coronary stenosis was defined as a >1% reduction in longitudinal strain with an increase in postsystolic shortening of at least two contiguous segments in the specific coronary artery territory at peak stress compared with baseline. Twenty-five patients had significant coronary artery disease (>70% stenosis on coronary angiography), including 17 with left anterior descending coronary artery stenosis and 19 with non-left anterior descending coronary artery stenosis. Overall, strain imaging provided no additional benefit over visual analysis in detecting significant stenosis per patient and per vessel among experts and fellows. Strain analysis by the fellows had significantly lower specificity and accuracy compared with the experts. Expertise affects strain evaluation for detecting significant coronary artery disease during DSE.