2.4. Definition of IHD

Patients who reported severe chest pain and/or showed ST-segment elevation on electrocardiography, and those with significant stenosis or occlusion of a coronary artery, were diagnosed with acute coronary syndrome. Patients who had a history of myocardial infarction (MI) with electrocardiographic evidence of MI and abnormal wall motion on ultrasound echocardiography (UCG) were diagnosed with old MI. Patients who exhibited symptoms (i.e., chest oppression) and/or obvious ischemic findings on electrocardiography, UCG, stress test, and cardiac catheterization were diagnosed with angina pectoris. Asymptomatic patients with positive findings in the aforementioned examinations were diagnosed with silent myocardial ischemia.