Acute myocardial infarction (AMI) is the result of thrombotic occlusion due to activation of the coagulation system and platelets after rupture of a coronary atherosclerotic plaque. The recanalization rate of thrombolytic therapy is low, with a success rate of only 50%-70%, along with a narrow time window and many contraindications and complications, and the high residual stenosis after thrombolysis increases the rate of reinfarction and reischemia, then emergency stenting (PCI) can recanalize the occluded infarct-related artery (IRA) is considered to be the most effective treatment for AMI. Of course the incidence of in-stent thrombosis and major adverse cardiac events (Mace events) are higher after emergency PCI at AMI than after PCI in non-AMI patients, and the main reason for this is related to the presence of a higher proportion of poor stent apposition in emergency PCI patients. The use of post-stenting with a high-pressure balloon is the main method to solve this problem, but there is widespread controversy about the need for post-dilatation in emergency PCI for AMI. The Department of Cardiology, First Affiliated Hospital of Henan College of Traditional Chinese Medicine, Care Min I. It is better to be fast than slow, rather than long than short, and compete for time Coronary plaque rupture and thrombosis are the main pathogenesis of AMI, and restoring IRA recanalization as soon as possible so that the myocardium can be reperfused with blood as soon as possible is the key to reducing the death rate and infarct size in patients with myocardial infarction. Time is myocardium. Time is myocardium and time is life can thus be better reflected. For the selection of stents, metal bare stents and drug-coated stents are more advantageous than drug-coated stents in terms of improving prognosis in patients with acute myocardial infarction, and earlier studies suggest that metal bare stents are more advantageous than drug-coated stents in terms of stent endothelialization and reduction of in-stent thrombosis. However, in recent years, due to improvements in stent fabrication and its coating process and the enhancement of anticoagulant drugs, a 2011 study of the Evaluation of Stent Application in Acute Myocardial Infarction Xience-V (EXAMINATION) trial applied everolimus-eluting stents (EES) in the treatment of ST-segment elevation acute myocardial infarction (STEMI), with the aim of evaluating the use of EES and cobalt-chromium bare metal stents in the PCI treatment of patients with STEMI. The aim was to evaluate the safety and efficacy of EES and cobalt-chromium bare metal stents (BMS) in the treatment of STEMI patients with PCI. The results showed a numerical but non-statistically significant reduction in the incidence of the primary endpoint event, mainly attributable to a trend toward a lower rate of revascularization. In contrast, the incidence of definite and definite/probable in-stent thrombosis (ST) was significantly lower, suggesting that high-risk STEMI patients are safe to receive EES placement. The results of this all-source randomized trial are highly representative of real-world populations. This provides a new reference for surgeon stent selection during emergency PCI for AMI. Clinical studies have also found greater clinical benefit in emergency PCI in preventing recent in-stent thrombosis, where the stent should be selected to be as long as possible to cover the entire length of the lesion and achieve normal-to-normal goals. If short stents are chosen for implantation, there is a risk of tearing of the fibrous cap at the edge of the stent, which may lead to acute in-stent thrombosis, and there is also a risk that the lesion may not be completely covered by the stent, because the plaque rupture is not necessarily the most stenotic, but in fact the “shoulder” of the plaque, which is the “shoulder” of the plaque. Intravascular ultrasound (IVUS) and infrared coherence angiography (OCT) can better understand the local information of coronary lesions and better guide stent implantation; therefore, the choice of long stents is necessary and safer. However, emergency long stent placement also has its own disadvantages, such as the tendency to drift distally during long stent release, and the possibility of inadequate stent expansion, poor wall apposition, edge tearing and tissue prolapse due to the relatively low and uneven local pressure of the balloon during long stent release; also, because acute myocardial infarction is an unstable plaque rupture followed by acute thrombosis blocking the vessel, diffuse lesions, combined with spasm, when When the balloon is pre-expanded several times or during the release of the stent, the thrombus can be displaced or even dislodged, resulting in impaired blood flow in the distal vessels, manifesting as “slow flow” or “no reflow”. Another study showed that the incidence of in-stent thrombosis after emergency PCI was significantly higher in AMI patients (4.2%) than in non-AMI patients (0.9%). In an analysis of IVUS examination to predict in-stent thrombosis in drug-coated stents, the main risk factors were found to be poor stent apposition and incomplete stent expansion, which is associated with delayed healing due to early incomplete stent expansion and late positive vessel remodeling, which is more common in AMI than in stable angina. Therefore, in terms of technical aspects, stent implantation in AMI should be carefully evaluated by a comprehensive analysis, including the degree of residual stenosis after intra-IRA thrombus aspiration or and balloon expansion, lesion length, degree of calcification, opening lesion, stent release pressure, and other factors, and carefully considered for optimal selection. Second, post-balloon dilation, a comprehensive choice between pros and cons Under normal circumstances, post-balloon dilation with high pressure is often chosen after stent implantation in order to make better stent apposition. The benefits of post-balloon dilation are obvious: post-balloon dilation can squeeze the plaque more fully, make the stent adhere to the wall more fully, reduce the elastic retraction of the stent, reduce the residual stenosis, make the offender’s vessel opening more fully, and effectively prevent the formation of in-stent thrombosis in the long term. This has been confirmed by the results of several clinical trials. However, in addition to the above benefits, there are also unavoidable hazards when dealing with the offender vessel in acute myocardial infarction patients with emergency PCI. It has been found that the expansion of the offender vessel after emergency PCI balloon hypertension is prone to different degrees of intimal tears at both edges of the stent and occlusion of the branch vessels around the lesion. High-pressure dilatation can cause intimal tearing, myocardial microvascular spasm, microthrombosis or occlusion. More commonly, post-balloon dilation leads to local residual wall thrombus and atheromatous plaque fragments dislodged and embolized distally, coupled with capillary endothelial cell damage and interstitial congestion and swelling, resulting in microvascular blockage, manifesting as “slow flow” or “no reflow” phenomenon. Studies have shown that the incidence of no-reflow phenomenon increases significantly with the increase of stent balloon dilation pressure, especially when the stent release pressure is ≥1823.4kPa (18atm). Repeated post-balloon dilatation also increases myocardial ischemia accrual time and deteriorates cardiac function. Therefore the aim of emergency PCI should be followed to open the vessel and restore reperfusion as soon as possible. However, the use of post-hypertensive balloons is sometimes necessary, and foreign reports indicate that the use of post-hypertensive balloons during AMI PCI is 14-64%. The surgeon should be careful to grasp that post-emergency PCI balloon dilation should not be used routinely during AMI, but should be used purposefully, i.e., in selective cases and at selective sites (i.e., “targeted”), so that the advantages of post-hyperbaric balloon dilation can be fully utilized and its disadvantages minimized. The author proposes the following recommendations based on literature reports and personal clinical experience: 1, AMI onset within 3 hours; 2, hemodynamic stability and small thrombus load; 3, AMI disease due to in-stent thrombosis; 4, stent residual stenosis is obvious; 5, calcification, distortion, long lesions after adequate thrombus aspiration stent implantation; 6, emergency PCI, phase II treatment of non-IRA; 7, emergency Three months or six months after PCI, when in-stent stenosis is shown on repeat imaging and poor stent apposition is found on IVUS or OCT. In combination with the above clinical conditions can focus on the cautious use, but the number and pressure of post-dilatation should be strictly controlled. For reference only! , the