The Role of Layer-Specific Strain Echocardiography in The Diagnosis of Severe Coronary Artery Disease

Aim: Several imaging techniques are in use for diagnosis and risk assessment in patients with suspected stable coronary artery disease (S-CAD). Measurement of global longitudinal strain (GLS) by two-dimensional speckle tracking (2D-STM) is a more accurate and reliable technique compared to transthoracic echocardiography. It provides a quantitative measure of left ventricular function. The aim of this prospective study was to determine the relationship between resting layer-specific longitudinal strain values and severe coronary lesions in patients with suspected S-CAD. Materials and Methods: A total of 242 patients with suspected S-CAD were included in this study. They were scheduled for elective coronary angiograph. Patients were divided into two main groups: with (n=117) and without severe coronary artery disease (CAD) (n=125). Layer-specific GLS values were compared between groups as mid-myocardial, endocardial and epicardial layers, using 2D-STM. Results: This study showed that GLS values of all layers were significantly lower in patients with severe CAD compared to controls (p<0.001). ROC curves were constructed to evaluate the diagnostic performance of GLS values and the area under the curve was 81-82% in three slices. The cut-off values were calculated to be -19.5 for the GLS mid-myocardium, -22.6 for the GLS endocardium, and -16.5 for the GLS epicardium. Conclusion: As a result, GLS assessment by 2D-STM showed that GLS values were lower in all layers with severe CAD, suggesting that GLS assessment may be useful for detecting severe CAD. However, layer-specific strain analysis showed no incremental value over GLS analysis. These findings should be further investigated and improved in subgroups with a more homogeneous distribution. Further larger studies are needed.