Mental Stress-Induced Myocardial Ischemia Detected by Global Longitudinal Strain and Quantitative Myocardial Contrast Echocardiography in Women With Nonobstructive Coronary Artery Disease

The utility of radionuclide myocardial perfusion imaging including positron emission tomography (PET) for diagnosing mental stress-induced myocardial ischemia (MSIMI) is clinically restricted. This study aims to assess the diagnostic performance of novel echocardiographic techniques, including automated strain and quantitative myocardial contrast echocardiography (MCE) with dedicated software and deep neural network model, for MSIMI detection. The secondary objective was to explore the correlation between changes in myocardial blood flow and MSIMI. Seventy-two female patients ages 18 to 75 with angina and nonobstructive coronary artery disease (ANOCA) and 23 healthy controls were prospectively recruited. Both echocardiography with contrast agent and PET imaging were performed during structured mental stress testing. Mental stress-induced myocardial ischemia was defined as a summed difference score ≥3 on PET. Echocardiographic parameters including left ventricular global longitudinal strain, β, and A × β were obtained, and their trends during mental stress testing were observed. ΔGLS was defined as the ratio of difference between global longitudinal strain values at stress and rest to the rest data. β reserve and A×β reserve were respectively calculated. Thirty-two ANOCA patients (44%) and 1 control (4%) were diagnosed with MSIMI (P