Value of Resting and Stress Myocardial Deformation Assessment by Two Dimensional Speckle Tracking Echocardiography to Predict the Presence, Extent and Localization of Coronary Artery Affection in Patients with Suspected Stable Coronary Artery Disease

BACKGROUND: Myocardial deformation indices are considered as sensitive markers of ischemia. They are useful in the quantification of hemodynamic significance of coronary artery disease (CAD). Dobutamine stress echocardiography (DSE) is a non-invasive method with established diagnostic accuracy. Limited studies have been published exploring the implementation of speckle tracking imaging during DSE. Hence we sought to evaluate the utility of speckle tracking echocardiography (STE) for detection of left ventricular strain and strain rate during DSE in patients with stable coronary artery disease (SCAD). MATERIALS AND METHODS: 50 patients of SCAD were prospectively recruited. All patients underwent dobutamine speckle tracking echocardiography and coronary angiogram. Global longitudinal strain (GLS%) /strain rate(GLSR 1/S) and Global radial strain (GRS%)/strain rate (GRSR1/S), Global circumferential strain (GCS%)/strain rate (GCSR1/S) were calculated at rest, at dobutamine dose 5mcg/kg/min, at peak stress and at early recovery (3min after stress). Obstructive CAD was defined as greater than 50% of coronary artery luminal narrowing. RESULTS: Out of 50 patients, significant stenosis on coronary angiogram was observed in 22(44%) patients. Among them 10 (45%) had single vessel disease (SVD), 5 (22%) had double vessel disease (DVD) and 7 (33%) had triple vessel disease (TVD). Left anterior descending artery (LAD) involvement was seen in 18 (82%) patients, Left circumflex (LCX) in 15(68%) and Right coronary artery (RCA) in 8 (36%) patients. Patients with significant CAD were more frequently male (68%). All analysed STE parameters at peak dobutamine doses and during recovery were significantly lower in patients with significant stenosis than in patients without siginificant stenosis. GLS(%)( -16.55?2.75 vs -21.11?2.50, p value 0.02 ) and GLSR (1/S)( -1.54?0.25 vs -1.75?0.84 p value=0.04), GRS(%) (34.45?3.50 vs 49.54?2.85, p value