Two-Dimensional Speckle-Tracking during Dobutamine Stress Echocardiography in the Detection of Myocardial Ischemia in Patients with Suspected Coronary Artery Disease

Abstract

Two-dimensional speckle-tracking applied to dobutamine stress echocardiography (DSE) may aid in the detection of coronary artery disease (CAD). The aim of this study was to determine the value of strain, strain rate, and postsystolic strain index (PSI) measured by speckle-tracking during DSE in the evaluation of the presence, extent, and severity of myocardial ischemia. Fifty patients 63±7years of age with intermediate probability of CAD were prospectively recruited. All patients underwent DSE, quantitative positron emission tomographic perfusion imaging, and invasive angiography. Regional peak systolic longitudinal strain, strain rate, and PSI were measured at rest, at a dobutamine dose of 20μg/kg/min, at peak stress, and at early recovery (1min after stress). Obstructive CAD was defined as >75% stenosis or 40% to 75% stenosis combined with either fractional flow reserve<0.80 or abnormal findings on myocardial perfusion positron emission tomography. Obstructive CAD was detected in 22 patients and in 36 of 150 coronary arteries. Strain analyses showed the highest reproducibility at rest, at a dobutamine dose of 20μg/kg/min, and at early recovery. Increased PSI and reduced strain during early recovery were the strongest predictors of obstructive CAD and were associated with the extent, localization, and depth of myocardial ischemia by positron emission tomography. On vessel-based analysis, strain, PSI, and visual analysis of wall motion provided comparable diagnostic accuracy, whereas the combination of strain or PSI with visual analysis provided incremental value over visual analysis alone. Assessment of systolic or postsystolic strain by speckle-tracking echocardiography during early recovery after DSE can help in the detection of hemodynamically significant coronary stenosis compared with visual wall motion analysis alone.