Myocardial strain analysis by 2-dimensional speckle tracking echocardiography improves diagnostics of coronary artery stenosis in stable angina pectoris

Abstract

Purpose: To determine if 2-Dimensional Strain Echocardiography (2DSE) performed at rest in patients with suspected Stable Angina Pectoris (SAP) is able to improve the diagnosis of the presence of significant Coronary Artery Disease (CAD). Methods: In total 296 consecutive patients with clinically suspected SAP, no previous cardiac history and a normal ejection fraction were included. All patients were examined by 2DSE, Exercise Electrocardiogram (ECG) and coronary angiography. 2DSE was performed in the three apical projections. Peak Regional Longitudinal Systolic strain (RLS) was measured in 18 myocardial sites and averaged to provide Global Longitudinal Systolic strain (GLS). Duke Score (DS), including ST-depression, chest pain and exercise capacity, was used as the outcome of the exercise ECG. Results: Patients with an area stenosis ≥70% in at least one epicardial coronary artery were categorized as having significant CAD (n=108). GLS was significantly lower in patients with CAD compared to patients without CAD (17.1% vs. 18.8%, p<0.001), and remained an independent predictor of CAD after multivariable adjustment for baseline data, exercise ECG and conventional echocardiographic parameters (OR 1.17 (1.0-1.3, p=0.012) per 1% decrease). Area under receiver operating characteristics curve (AUC) for exercise ECG and GLS in combination was significantly higher than AUC for exercise ECG alone (0.84 vs. 0.78, p<0.004). Furthermore, RLS predicted significant stenosis in corresponding coronary arteries (Figure 1). Figure 1. RLS in stenotic vs non-stenotic segments Figure 1. RLS in stenotic vs non-stenotic segments Conclusion: In patients with suspected SAP GLS at rest is an independent predictor of significant coronary artery disease and significantly improves the diagnostic performance of exercise ECG. Additionally, RLS can identify which coronary artery that suffers from significant stenosis.