Global Longitudinal Strain Measured by 2D Speckle Tracking Echocardiography in Stable Angina Patients and Their Angiographic Correlation

Introduction & Objective: Myocardial strain assessed by Speckle Tracking Echocardiography (STE) quantifies myocardial deformation which appears earlier than wall motion abnormality. Thus Global Longitudinal Strain (GLS) assess myocardial function in early stage of ischemic evolution. The aim of the study was to estimate GLS in coronary angiography undergoing intermediate to high risk stable angina patients which could correlate GLS with significant Coronary Artery Disease (CAD), determine cut-off value for identifying significant CAD and find sensitivity and specificity for the GLS cut-off value. Methods: This was a cross-sectional study which included stable angina patients with normal left ventricular ejection fraction who were otherwise indicated to undergo coronary angiography. All the patients underwent STE and their GLS value was calculated. The coronary artery angiography findings were then correlated with GLS using appropriate statistics. Results: A total of 89 patients were included. There was a strong negative correlation (r = -0.824) between GLS value and presence of significant CAD. The mean values of GLS for single vessel disease, double vessel disease and triple vessel disease were -15.94 ± 7.30, -15.28 ± 0.58 and -11.59 ± 1.35 (P <0.001) respectively. The GLS cut-off value ≤ -18.5 identified significant CAD and the sensitivity, specificity and area under curve for this cut-off value was 96.8%, 85.2% and 0.937 respectively (P<0.001). Conclusion: Global longitudinal strain is a sensitive, specific and excellently accurate modality that had a strong negative correlation with presence and severity of significant CAD.