1.What is coronary intervention? Coronary intervention (PCI) refers to the treatment of coronary artery stenosis by delivering therapeutic devices percutaneously through the peripheral arteries into the coronary arteries. With the improvement of devices, the treatment effect can be comparable to surgery, and the trauma to patients is small, so patients can easily accept it, so it has been developed rapidly in recent years. 2.What are the common interventional measures for coronary artery treatment? The most common ones are percutaneous transluminal coronary angioplasty (PTCA) and intracoronary stent implantation and atheromatous plaque ablation techniques developed on this basis, such as plaque spinning, directional plaque spinning, etc. 3.What are the common complications of coronary intervention? Common complications of PCI include: (1) coronary artery injury, which can lead to acute infarction, coronary artery perforation, pericardial tamponade, branch occlusion, etc.; (2) coronary artery thrombosis; (3) perforating vessel injury, which can lead to hematoma, pseudoaneurysm, arteriovenous fistula, thrombosis, etc.; (4) non-vascular complications, including contrast allergy, contrast nephropathy, cardiac impairment, etc. 4.What is meant by percutaneous transluminal coronary angioplasty (PTCA)? PTCA refers to percutaneous puncture of peripheral arteries and delivery of a catheter with a balloon to the site of coronary artery lesions. The stenotic lesions are dilated by filling the balloon with pressure, thereby improving the stenosis and myocardial blood supply and relieving symptoms. 5.What patients need percutaneous transluminal coronary angioplasty (PTCA)? (1) Stable angina with poor drug therapy; (2) Unstable angina and acute myocardial infarction; (3) Stenosis of the graft vessel after coronary artery bypass grafting; (4) Stenosis of the lumen at the lesion site greater than 50%, usually above 75%, or restenosis after PCI. 6.What is intracoronary stenting? After the stenotic lesion is dilated by balloon, restenosis will occur in 40% of the lesions, and some patients will have acute coronary occlusion leading to acute infarction or death, so after the vasodilatation is completed, a metal stent is usually implanted in the lesion to permanently open the lesion. Stenting is performed to reduce collapse and acute occlusion after plaque tearing, to increase the safety of the procedure, and to reduce restenosis. 7.What kind of stents are implanted in the coronary arteries and what types are currently available? The vast majority of intracoronary stents used today are metal stents with a mesh structure that effectively prevents elastic retraction and negative remodeling of the vessel, thereby effectively reducing restenosis rates. According to whether they carry drugs on their surface, they are divided into drug-coated stents and ordinary bare metal stents. 8.What is drug-coated stent and how is its efficacy compared with ordinary stents? Drug-coated stent refers to a drug that can be carried on the surface of ordinary metal stent in various ways and can slowly release drugs that inhibit smooth muscle cell proliferation, thus significantly reducing the incidence of restenosis. 9.Which patients need stents in the coronary arteries? Since the restenosis rate after balloon dilation alone is as high as 30-50%, stents are currently routinely implanted after balloon dilation in coronary arteries with vessel diameters greater than 2.0 mm, especially in cases of acute occlusion risks such as plaque fast tears and vessel entrapment after balloon dilation. In the case of small vessels (≤2.0 mm in diameter) and branch vessels, due to the high restenosis rate of stent implantation, it is currently advocated that balloon dilation alone is sufficient without routine stent implantation. 10.Does the stent placed in the coronary artery fall off and need to be removed after a period of time? When a stent is implanted in a coronary artery, the stent balloon needs to be dilated and released with a pressure of 10 atm (1 atm = 760 mmHg = 101.325 kPa) or more, so that the stent is tightly attached to the vessel wall, and therefore it rarely falls off. After about one month of stent implantation, the new endothelium will cover the surface of the stent, so that the stent becomes part of the vessel wall and therefore does not need to be removed. 11.What is percutaneous intracoronary plaque revascularization and which revascularization devices are commonly used? Intracoronary directional transluminal atherectomy (DCA) is a method of removing plaque tissue and removing it from the body by guiding a cutting device percutaneously through a finger-guided wire to the lesion site. The components of a typical DCA catheter include a metal rotary blade cartridge with a support balloon, a plaque tissue collection lumen, and a rotatable catheter. 12. What are the indications for percutaneous intracoronary plaque spinning? The intracoronary plaque spinning and grinding procedure is mainly used for the reconstruction of blood flow in hard, calcified lesions that cannot be treated by other methods. The fibrotic and calcified plaque is removed by a high-speed rotating grinding head, thus improving the degree of stenosis at the lesion site, on the basis of which traditional treatments such as balloon dilation and stent implantation can be performed. 13.Why does restenosis occur after balloon dilation or stent implantation? The mechanisms of restenosis after balloon dilation alone are: (1) vascular elastic retraction; (2) negative vascular remodeling; (3) smooth muscle cell hyperplasia and extracellular matrix aggregation. The mechanism of stenting to reduce restenosis rate is mainly to effectively stop vascular elastic retraction and negative remodeling, but there is still smooth muscle cell proliferation, so restenosis will still occur. Drug-coated stents carrying drugs that inhibit smooth muscle cell proliferation can significantly reduce the restenosis rate. 14.How to determine the occurrence of restenosis after coronary intervention? If a clinical event such as angina recurrence, myocardial infarction or sudden death occurs after coronary intervention, and the stenosis rate of the vessel diameter at the intervention site is >50% on review of coronary angiography, restenosis is considered to have occurred. 15.Do I need to continue coronary drug treatment after successful coronary intervention? Since coronary intervention only improves the stenosis of coronary arteries, but the atherosclerotic lesions of the vessels themselves still exist, it is necessary to continue drug therapy after the procedure, including antiplatelet therapy, lipid-lowering therapy, anti-anginal therapy, etc. It is also necessary to continue to quit smoking, control blood pressure, blood sugar and other risk factors, so as to reduce the progression of atherosclerosis and the occurrence of restenosis. 16.How long after successful coronary intervention should I go for a follow-up coronary angiography? Since restenosis after coronary intervention usually occurs within six months, it is recommended to review coronary angiography about six months after intervention, and those with suspected recurrence of myocardial ischemia should be reviewed by angiography in time for early detection of restenosis, poor stent apposition and other adverse events. 17.What if restenosis occurs in the coronary artery? If restenosis of coronary artery is found on review, re-PTCA, re-stenting, plaque ablation techniques (e.g. DCA, rotational grinding) and endovascular radiation therapy can be chosen according to patient characteristics and lesion morphology.