Value of global longitudinal strain by two dimensional speckle tracking echocardiography in predicting coronary artery disease severity

Abstract

Background: Significant coronary artery stenosis might cause persistently impaired longitudinal left ventricle (LV) function at rest. LV global longitudinal strain (LVGLS) can be accurately assessed by 2D speckle-tracking strain echocardiography(2D-STE). Objective: We aimed to evaluate the diagnostic accuracy of LV global longitudinal strain obtained by 2D-STE in prediction of severity of CAD. Methods: Eighty patients with suspected stable angina pectoris were included. They underwent transthoracic echocardiography (TTE) to measure LV ejection fraction, 2-D-STE to measure GLS and coronary angiography (CA). The patients were divided into two groups: group 1 (58 patients) with significant (>70%) CAD, and group 2 (22 patients) with non-significant (<70%) CAD. Images were obtained in the apical long-axis, four-chamber, and two chamber views. Regional longitudinal systolic strain was measured in 17 myocardial segments and averaged to provide global longitudinal strain (LVGLS). Results: There was significant decrease in GLS in group 1 compared to group 2 (−11.86 ± 2.89% versus −18.65 ± 0.79%, P < 0.000). The optimal cutoff value of GLS for prediction of significant CAD was −15.6% [AUC 0.88, 95% CI 0.78–0.96 p < 0.000]. The sensitivity, specificity and accuracy of GLS for detecting significant CAD were 93.1%, 81.8%,and 90% respectively.There was a significant positive correlation between GLS and EF (r = 0.33; p = 0.036).There was incremental significant decrease in GLS with increasing number of coronary vessels involved. Conclusion: Measurement of global longitudinal strain using 2D speckle tracking echocardiography is sensitive and accurate tool in the prediction of severe CAD.

Keywords

• CAD
• 2-D speckle tracking echocardiography
• Global strain
• Coronary angiography