Acute ST-segment elevation myocardial infarction (STEMI) is the result of acute thrombus occlusion of the lumen due to coronary plaque rupture, and emergency direct percutaneous coronary intervention (PCI) is currently the treatment strategy of choice for STEMI to open the infarct-related artery (IRA) and achieve “reperfusion” therapy in a timely manner. However, during the emergency PCI procedure, fresh thrombus or/and plaque dislodgement during conventional balloon dilation and stent placement often causes embolization of the distal vessel to varying degrees, resulting in “slow flow” or “no-reflow”. It also aggravates the systemic stress due to the long duration of the procedure. These are important factors that lead to deterioration, hemodynamic instability, and increased mortality, and seriously affect the immediate outcome and long-term prognosis of STEMI patients. Direct PCI is currently the best means of opening the occluded artery (IRA) to restore blood flow, and the thrombus load in the occluded associated vessel (IRA) is the most important factor directly affecting the outcome of emergency PCI. measures. Care Min, Department of Cardiology, The First Affiliated Hospital of Henan College of Traditional Chinese Medicine 1. Direct PCI for acute myocardial infarction preceded by thrombus aspiration improves prognosis Patients with acute ST-segment elevation myocardial infarction with thrombotic lesions undergoing direct percutaneous coronary intervention (PPCI) are at high risk of serious adverse cardiovascular events (MACE) and in-stent thrombosis. It is associated with increased myocardial microcirculatory embolism and no-reflow phenomenon due to unstable plaque debris and thrombus dislodgement, which severely affects patient prognosis. Thrombus aspiration devices use the principle of negative pressure aspiration to extract intracoronary thrombus from the body. The Thrombus Aspiration Study (TAPAS) trial has demonstrated that thrombus aspiration prior to balloon dilation or stent placement during emergency PCI significantly improves myocardial reperfusion, reduces the incidence of no-reflow, and reduces mortality within 1 year. The heavier the thrombus load, the greater the benefit from thrombus aspiration management. The thrombus score is defined as follows: 0, no thrombus; 1, vague thrombus shadow; 2, definite thrombus image with a length of less than 1/2 the intravascular diameter; 3, definite thrombus with a length between 1/2 and 2 times the intravascular diameter; and 4, definite thrombus with a length greater than 2 times the intravascular diameter. A coronary angiogram showing one of the following characteristics of IRA is indicative of high thrombus load: ① a long strip of thrombus greater than three times the inner diameter of the reference vessel ② the presence of a floating thrombus proximal to the occlusion ③ a strip of thrombus >5 mm long proximal to the occlusion ④ a sudden flush occlusion without progressive thinning of the vessel proximal to the occlusion ⑤ the reference lumen inner diameter of the IRA >4.0 mm ⑥ contrast retention distal to the occlusion, etc. The TIMI grading of coronary blood flow and the grading of myocardial tissue perfusion color rendering (cardiac agent contrast staining density, MBG) were evaluated as follows: blood flow grading, TIMI: grade 0, no filling and emptying in the myocardium of the infarct-related area; grade 1, slow filling and no emptying in the myocardium of the infarct-related area, and the contrast agent is still retained when the image is repeated after 30 seconds; grade 2, complete filling and emptying in the myocardium of the infarct-related area, but MBG grading: MBG grade 0, no myocardial imaging; MBG grade 1, only minimal myocardial imaging; MBG grade 2, moderate myocardial imaging, but significantly different from ipsilateral or contralateral IRA-infested areas; MBG grade 3, normal myocardial imaging, comparable to ipsilateral or contralateral non IRA-dominated areas; when there is persistent myocardial shadowing, this phenomenon shows leakage of contrast outside the vessel and is classified as grade 0. The MBG grade 0-2 is defined as poor myocardial perfusion imaging, and MBG grade 3 is defined as normal myocardial perfusion. It was found that even with direct PCI of the offender vessel to achieve TIMI grade 3 blood flow, approximately 15-30% of patients still had no myocardial tissue level perfusion and exhibited persistent chest pain and ST-segment elevation on the electrocardiogram. The TAPAS study is a prospective randomized controlled study with a follow-up period of up to 1 year. The trial enrolled 1071 patients with STE.MI, who were randomized to the conventional PCI treatment group (536 patients) and the thrombus aspiration catheter-supported PCI group (535 patients). There was no significant difference in clinical and imaging characteristics between the two groups. The results showed that thrombus aspiration was successfully completed in nearly 90% of the cases in the thrombus aspiration group, with no thrombus aspiration-related complications. Compared with the thrombus aspiration group alone, patients in the thrombus aspiration group had significantly improved myocardial perfusion after PCI, a significantly lower rate of myocardial MBG grade 0 and 1 (17% vs 26%, P<0.001), and a significantly higher rate of complete S-T segment regression on the ECG (57% vs 44%, P<0.001). The 30-day postoperative study showed a strong correlation between clinical outcome and degree of myocardial perfusion. The mortality rate in patients with myocardial perfusion grades 0 to 1, 2.9%, and 3 in the thrombus aspiration group was 5.2%, 2.9%, and 1.0%, respectively (P=0.003), and the combined event rates of re-myocardial infarction, target vessel reoperation, and death were 14.1%, 8.8%, and 4.2% in all three (grades 0 to l, 2, and 3), in that order (P<0.001). 1-year follow-up showed that, similar to the 30-day post-procedure results were similar: there was a significant correlation between myocardial MBG staining, death, or death combined with recurrent myocardial infarction at 1 year (P=0.001), and mortality remained lower in the aspiration catheter group than in the conventional PCI group (P=0.04). This study suggests that myocardial perfusion after PCI in STEMI patients is a good predictor of future prognosis, and that the use of a thrombus aspiration device during PCI is effective in reducing the risk of death and recurrent myocardial infarction, and that this benefit can be maintained for at least 1 year. The reason for this may be that the thrombus aspiration group reduces embolization of the distal vessels and reduces the area of the dying myocardium due to the prior maximum removal of the thrombus and other substances causing microvascular embolism. At the same time, the more adequate local lesion exposure after thrombus aspiration facilitates stent selection, the reduction of stent length contributes to restenosis, and the increase in postoperative stent diameter suggests that thrombus removal may help reduce malapposition, all of which may play a role in reducing the occurrence of MACE after direct PCI. 2. New elements of emergency PCI: Adequate opening after thrombus aspiration allows for elective stent placement In addition to PTCA and coronary stenting, PCI also includes techniques such as spin mill, directional spinotomy, aspiration, and laser angioplasty that can relieve coronary artery stenosis; conventional emergency PCI is the process of conventional balloon dilation and stent implantation in STEMI patients immediately after coronary stenting to determine IRA through the occluded lesion to the distal end. The newer emergency PCI has also given new content, namely thrombus aspiration combined with stent implantation, which has improved its efficacy to a new level. However, in clinical practice, there are some STEMI patients who have satisfactorily restored coronary blood flow using catheter aspiration alone, but also have complex lesions that are difficult to handle satisfactorily by interventional techniques, or who have mild residual stenosis, or who are hemodynamically unstable, etc. The procedure can be terminated here; after the condition is stabilized, another PCI or other "reconstruction" options can be selected. "Reconstruction". Emergency PCI requires two procedures to complete, except for the IRA, which is a single lesion. The principle is that only the IRA is treated in the emergency, and the rest of the non-IRA vascular lesions are completed in the second procedure. Although both procedures are also twice, the former is an emergency PCI, while the latter is a treatment of residual IRA stenotic lesions along with the treatment of non-IRA vascular lesions when the body recovers to an appropriate time under the protection of effective anticoagulation, antiplatelet and anti-inflammatory drugs. This undoubtedly evolves an emergency procedure into an elective general procedure with the same goals in mind, with obvious advantages. Stenting has been reported in STEMI patients with complete disappearance of residual stenosis on re-imaging within a few days after restoration of blood flow by simple catheter thrombus aspiration. Because approximately 68% of STEMI patients have less than 50% stenosis before infarction, restoration of the original state is possible after aggressive antithrombotic therapy. It is believed that the higher the emergency PCI release pressure, the higher the chance of no recurrent flow; on the contrary, the lower the stent expansion pressure, the higher the chance of in-stent thrombosis, which is related to poor stent apposition leading to incomplete endothelialization later. Therefore, the chance of in-stent thrombosis after STEMI stenting is also higher. The staged approach avoids the acute hyperresponsiveness period, i.e., simplification of treatment at the time of emergency, and then elective full treatment after the body has recovered to a certain extent, which allows the use of high-pressure balloon post-dilatation and is less likely to occur without recurrent flow, which is more beneficial to the long-term prognosis. 3. thrombus aspiration catheter and thrombus removal, and intracoronary administration of antithrombotic drugs Whether thrombolytic therapy or catheter aspiration thrombus can make most patients better restore However, because of the presence of residual stenosis with high-load thrombus and a high chance of recurrent post-infarction angina, recurrent myocardial infarction, and other cardiac events, these measures cannot be used as treatment endpoints and require further coronary angiography at an elective date to determine the extent of residual stenosis and the degree of stenosis in non-infarcted vessels for complete coronary revascularization. However, aggressive intensive antithrombotic therapy, including heparin, IIb IIIa receptor antagonist (Synephrine) and dual antiplatelet agents, is required during both treatments, especially after the first opening of the occluded vessel, in order to provide the opportunity and good preoperative preparation for the second procedure. In clinical practice, it has been found that if the thrombus load is high after coronary artery opening coronary infusion of IIbIIIa receptor antagonist, the thrombus can be found to reduce or disappear in a few minutes; Synephrine is injected in 3 minutes, the effect is seen in 5 minutes, and the platelet aggregation function can be inhibited by >90% in 30 minutes in the case of intravenous infusion; compared with the intravenous route of administration, intracoronary infusion of glycoprotein IIb/IIIa via guideline catheter receptor inhibitors by intracoronary infusion via the guiding catheter increased intracoronary drug concentrations compared with intravenous administration. However, there are shortcomings in the perfusion of drugs into the aortic root and shunting to non-offender vessels during trans-guidance catheter administration. Transaspiration catheter administration can avoid these shortcomings and achieve increased efficacy while reducing adverse events. Intracoronary infusion of IIbIIIa receptor antagonists with transvenous administration has been clinically shown to improve coronary TIMI classification and improve the incidence of recent cardiovascular events. The thrombus aspiration catheter administration is different from the coronary guideline catheter administration in that a peak drug concentration is formed in the offender vessel after drug injection, and the inhibition rate of platelet aggregation function of Synephrine is proportional to the local concentration, so the local antiplatelet function will be more obvious, which is sufficient to counteract the hypercoagulable state of the lesion rupture site, and undoubtedly the clinical effect is better. However, after the occluded coronary artery thrombus is aspirated by aspiration catheter, the unstable plaque rupture is re-exposed and a large amount of tissue factor in its lipid nucleus comes into contact with the restored coronary blood flow again, thus the chance of local thrombus formation again is greatly increased and it is easy to form post-infarction angina or myocardial extension. In addition to aspirating mechanical masses (thrombi, plaque fragments) and inflammatory material, the plain aspiration catheter provides a route for superselective perfusion of drugs that can immediately counter and prevent secondary hypercoagulable states. Early administration of IIbIIIa receptor antagonists during emergency PCI has been shown to significantly improve immediate coronary flow and near-term clinical outcomes without increasing the risk of bleeding; intracoronary administration via guideline catheters is superior to intravenous administration, and thrombus aspiration catheter administration is even more effective.