Chest pain after stent implantation is generally seen in the following cases: 1, thrombosis, which is a serious complication of acute myocardial infarction; acute thrombosis within 24 hours, subacute thrombosis within 1 month, delayed thrombosis within 1 year, and very late thrombosis over 1 year. 2, vasospasm, after the implantation of stent, the stent can induce coronary spasm and lead to chest pain, which is transient and usually disappears in 1-2 weeks. Yao Yucai, Department of Cardiology, Shandong Qianfo Mountain Hospital 3, residual lesions, sometimes patients have multiple lesions in multiple branches, stents are only used to solve severe stenosis lesions, but spasm may also occur in lesions with mild stenosis leading to myocardial ischemia and chest pain. 4, branch affected, common in bifurcation lesions in the main branch after the implantation of stents resulting in branch opening compression stenosis, or aggravation of the original stenosis resulting in postoperative chest pain symptoms, often manifested as chest pain at the beginning of activity, with increased activity chest pain gradually disappeared. 5.Stent restenosis, which often occurs within 3 months to 1 year after stent implantation, mainly manifests as worsening exertional angina. 6.Non-cardiogenic chest pain, i.e. chest pain unrelated to coronary arteries, such as respiratory and digestive system diseases, etc.