1, patients with significant chest pain or chest tightness, especially those who can be relieved by rest or can be relieved by drugs such as nitroglycerin, should consider whether coronary angiography should be done. At this time, the angiography has important value for the diagnosis and estimation of the patient’s prognosis. Whether the next step is conservative medication or PCI (commonly understood as stenting) or bridge surgery, imaging is needed to evaluate the risk and identify the lesion. Not only for diagnostic purposes, but also to guide treatment. Even for patients who cannot undergo surgery for various reasons, because the lesion is clear, it is easier for the physician to provide targeted medical treatment, and the outcome is very good. Refusing to have a coronary angiogram because one feels that one will not undergo the procedure regardless of the condition often makes the treatment somewhat blind. Patients with serious conditions may lose the opportunity of treatment, which may lead to the aggravation of the disease; while patients with light conditions may be over-treated and take some drugs that could have been dispensed with as a result. For some patients with atypical chest pain, some non-invasive diagnostic tests, including echocardiography, ECG exercise test, Holter monitoring, nuclear myocardial imaging, etc., often have only vague diagnostic results, and such patients often have repeated emergency visits due to chest pain. For such patients, coronary angiography can provide definite evidence, especially for some menopausal female patients with atypical chest pain, ECG often shows that myocardial ischemia cannot be excluded, although coronary angiography is mostly negative result, it is also useful to prevent wrongly taking angina as the direction of treatment and avoid damaging the patient’s lifestyle and deprivation of work opportunities. 3, for patients with coronary artery disease that has been clearly diagnosed by other means, the next treatment plan, whether conservative medication or surgery, requires imaging to clarify the plan, especially for patients with recent frequent angina attacks or patients with persistent chest pain that has lasted more than half an hour, coronary angiography should be done as soon as possible to clarify the lesion. 4. In patients with aortic valve lesions (stenosis and/or insufficiency), the cause of angina can be either coronary artery disease, valvular disease or both, and it is very important to estimate the condition correctly before surgical treatment. Angiography can help to develop an accurate surgical plan. In patients with valvular heart disease without chest pain, the imaging can occasionally reveal a meaningful stenosis in one of the coronary arteries, so that the bypass surgery can be performed together with the conventional valve replacement or repair surgery, which can prevent the patient from undergoing a second open-heart surgery in a short period of time and reduce the cost of surgery. 5.In principle, asymptomatic patients do not undergo imaging, but the following cases can be considered: (1)Those who have no symptoms of chest pain but abnormal ECG, as long as there is one or more abnormalities after several non-invasive examinations, can be the subject of imaging. (2) Individual cases requiring coronary clarification to determine the occupational type (e.g., astronaut, pilot, driver, etc.) are also necessary. (3) Hypertension, hyperlipidemia, diabetes mellitus, genetic history of coronary artery disease, smoking, obesity, and men >45 years old are all risk factors for coronary artery disease. If there are more than two risk factors and no contraindications to surgery, coronary angiography can also be performed to completely rule out coronary artery disease. As more and more patients undergo PCI surgery and heart bypass surgery, post-operative review often requires coronary angiography during the six-month to one-year period to understand the condition of the coronary arteries or the bridge vessels and to determine the next step in treatment. However, coronary angiography should be done with caution if the patient is seriously ill, cannot lie down completely, is unconscious or has unstable blood pressure, has had a recent cerebrovascular accident, has a significant bleeding tendency or bleeding disorder, has significant liver or kidney insufficiency, or has recently completed surgery for a large trauma in the last few days.