I. Will the stent move in the coronary artery? The stent diameter is expanded in a ratio of 1.1:1 when the stent is released, that is, the stent diameter is slightly larger than the vessel diameter, and the stent is closely or even partially embedded in the vessel wall, so it will not move in the vessel. Second, can the stent be removed after implantation? As mentioned above, the stent diameter and the vessel diameter are expanded in the ratio of 1.1:1 when the stent is released, that is, the stent diameter is slightly larger than the vessel diameter, and the stent is tightly or even partially embedded in the vessel wall, so the stent cannot be removed. If it is forced to do so, it will cause serious damage to the blood vessel. Third, do I need to continue to take medication after stent implantation? In the article “Treatment of coronary heart disease”, I described the treatment of coronary heart disease in detail. There are three main reasons for the need to continue taking medication after stent implantation: First, coronary artery disease is a lesion involving the entire coronary bed, but the degree and nature of the lesion varies from site to site. Stent implantation only solves the problem of severe stenosis or plaque instability in one site, while other sites may still have plaque instability and continued aggravation of atherosclerosis, all of which need to be prevented or treated by medication. Secondly, since the implanted stent is not our own tissue, there is a risk of clot formation in the stent. Only after the endothelium of our own blood vessels grows into the stent and completely covers the stent, this risk of clot formation in the stent is reduced, and this process takes more than one year, so the continuous use of 2 antiplatelet drugs needs at least 1 year, in order to reduce the risk of clot formation in the stent. Third, the risk of restenosis in the stent is still present at the site of stent implantation, even if a drug-coated stent is implanted, according to statistics, the chance of restenosis in the stent 2 years after stent implantation is about 10%, and drug therapy is beneficial to reduce restenosis in the stent. Fourth, can MRI be done after stent implantation? People who ask this question actually have the following concerns: Will MRI cause stent displacement? Will MRI cause the stent site to heat up and cause damage? Will the stent affect the imaging of MRI? In fact, this question is answered in the instructions of the stent. Most of the stent bones are made of alloys, such as 316L stainless steel, cobalt-chromium alloy, nickel-titanium alloy, etc. MRI below 3.0 T will not cause displacement of these stents; the local temperature of the stent may increase 1-2 degrees Celsius without causing tissue or blood damage. Finally, stents do not affect MRI unless the site of imaging is adjacent to the stent implantation site. However, since the structure and process of stents are constantly being improved, it is safer to consult the physician who implanted the stent if necessary. V. How long does the dual antiplatelet therapy need to last after stenting? The current stent implantation requires the combination of 2 anti-platelet drugs for more than 1 year. One of them is usually enteric aspirin tablets 75mg to 100mg per day, the other is clopidogrel or tigretol, clopidogrel 75mg per day, and in the case of tigretol 90mg twice a day. Aspirin alone can be used after one year. Patients with coronary artery disease need to take the drug for life.