Diagnostic Accuracy of Global Longitudinal Strain for Detecting Significant Coronary Artery Disease in Diabetic Patients without Regional Wall Motion Abnormality

AIMS: Speckle-tracking imaging is a novel method for assessing left ventricular (LV) function and ischemic changes. The aim of this prospective study was to assess the diagnostic accuracy of global longitudinal strain (GLS) and regional longitudinal strain (RLS) parameters at rest in comparison to stress echocardiography findings for detecting significant coronary artery disease (CAD) in patients with diabetes mellitus (DM). METHODS: We prospectively studied echocardiographic characteristics at rest with Speckle tracking echocardiography (2D STE) measures; then stress echocardiography and coronary angiography data in 34 diabetic patients without regional wall motion abnormality (RWMA) at rest. Patients were grouped according to coronary angiography and stress echocardiography results into two groups CAD (+) vs control group CAD (−). RESULTS: GLS at rest was lower in the CAD (+) group ((-14.2 % ± 3.1 vs -17.8 % ± 3.1 in the control group CAD (−), P=0.004). GLS at rest had the highest area under the ROC curve (AUC) (AUC 0.78, sensitivity 61%, specificity 91%,P=0.009) with the cut-off of -14.5% which is equal to predictive power of wall motion scoring index (WMSI) at peak stress to detect significant CAD (AUC=0.76 (95% CI 0.58–0.94, P= 0.016) with the cut-off value of 1.21). CONCLUSIONS: Global longitudinal strain at rest by STE showed excellent specificity (>90%) and good sensitivity (60%) for the diagnosis of severe CAD among the diabetic population with unknown CAD. This is the first study showing that GLS at rest with cutoff value at -14.5% had good and equal diagnostic accuracy as WMSI at peak stress to detect significant CAD among the diabetic population.