Global longitudinal strain (GLS) changes during dobutamine stress echocardiography as an indicator of coronary artery disease

Background/Introduction Τhe diagnosis of coronary artery disease (CAD) remains challenging, often requiring multi-modality imaging. Dobutamine stress echocardiography (DSE) holds an established position through the assessment of segmental wall motion and contraction disorders and the use of the wall motion score index (WMSI) of the left ventricle (LV). In recent years, the echocardiographic assessment of myocardial strain with the Speckle Tracking technique is increasingly used to assess the resting systolic performance of cardiac cavities. Left ventricular global longitudinal strain (GLS) has been better studied. However, the role of this method in detecting CAD during stress has not been adequately examined. Purpose The aim of the present study was to evaluate the incremental value of GLS changes during DSE in the detection of CAD in addition to WMSI changes. Methods Fifty two (52) subjects with clinical suspicion of CAD were examined. The mean age of the participants was 63 years and 35 (67 %) of them were male. Participants underwent a DSE. Both WMSI and GLS changes of the 18 segments of LV and the 3 segments of the free wall of the right ventricle (RV) were calculated. In order to rule-in / rule-out CAD, individuals with an abnormal DSE (n=27) were subjected to an invasive coronary angiography whereas them with normal DSE (n=25) to a computed tomography coronary angiography. Angiographic stenosis of ≥50% of the left main coronary artery or/and ≥70% of the left anterior descending, the circumflex artery, the right coronary artery or/and their major branches established the diagnosis of CAD. Changes in GLS during DSE were correlated with the presence of CAD. Results CAD was diagnosed in 21 (40 %) subjects. As expected, patients with CAD had significantly higher WMSI changes between rest and peak-dose stress compared to non-CAD individuals: +0.18 (from 1.05 to 1.23) versus +0.03 (from 1.00 to 1.03) (p<0.001 for the differences between the 2 groups) (see also Figure 1). Interestingly, changes in LV-GLS during stress were toward different directions in the CAD versus the non-CAD group: +0.9% (from -25.6% to -24.7%) versus -3.2% (from -24.7% to -27.9%) between rest and low-dose stress and +3.0% (from -25.6% to -22.6%) versus -4.3% (from -24.7% to -29.0%) between rest and peak-dose stress. Moreover, changes in RV-GLS during stress were also toward different directions in the CAD versus the non-CAD group: +0.9% (from -25.0% to -24.1%) versus -3.1% (from -25.0% to -28.1%) between rest and low-dose stress and +2.0% (from -25.0% to -23.0%) versus -6.2% (from -25.0% to -31.2%) between rest and peak-dose stress (p<0.001 for all differences between the 2 groups for LV-GLS and RV-GLS changes between rest and low-dose and between rest and peak-dose stress) (see also Figure 2). Conclusion(s) Both LV-GLS and RV-GLS changes during DSE emerge as promising echocardiographic indices that can contribute in the diagnosis of CAD.Figure 1Diagnostic accuracy of WMSI changes.Figure 2Diagnostic accuracy of GLS changes.