Cardiac stenting, or coronary stenting, is usually used in patients with coronary artery disease. Coronary stenting is usually not recommended in cases of mild coronary stenosis, severe coronary stenosis and coagulation abnormalities. 1. Mild coronary stenosis: Coronary stenting is usually not recommended for patients with coronary artery disease if their coronary artery stenosis is less than 70% on their own coronary angiogram. Because this stent is a foreign body, after stent implantation, you need to take lifelong oral anticoagulant aspirin, tegretol, clopidogrel. These medications have the potential to aggravate the risk of bleeding in the body. 2. Severe coronary artery stenosis: When the patient’s own coronary artery is severely narrowed, such as the left main stem occlusion and chronic occlusive lesions of the three blood vessels, due to the condition is too critical, if the coronary artery angiography stent implantation may lead to their own rupture of the blood vessels and endanger their lives, so it is recommended that the patient can go to the cardiovascular surgery coronary artery bypass grafting surgery treatment. 3. Abnormal coagulation function: If the patient has serious coagulation dysfunction, liver and kidney function abnormality, coronary artery stent implantation is also not allowed, so the patient can go to cardiovascular internal medicine consulting, consultation and treatment. When coronary artery disease is found, the patient should go to the hospital immediately for consultation and treatment. Whether coronary stent implantation is needed needs to be evaluated and decided by the doctor.