Optimal timing of microaxial flow pump(Impella CP) in AMI-related cardiogenic shock

INTERVENTION: Procedure/Surgery : Patients presenting with acute myocardial infarction‐related cardiogenic shock (AMICS) whose shock persists despite medical therapy and for whom the treating team has decided that Impella CP is indicated will be screened. After informed consent and confirmation of eligibility, participants will be randomized 1:1 through a secure web‐based system using randomly permuted blocks of varying sizes. The routine pre‐PCI (percutaneous coronary intervention) group will undergo Impella CP insertion immediately after allocation and before culprit‐lesion PCI. The selective post‐PCI group will undergo culprit‐lesion PCI first; Impella CP will be inserted only if prespecified intra‐procedural rescue criteria are met or shock persists or worsens after successful PCI. If all post‐PCI recovery criteria are met, PCI will be concluded without Impella CP. When Impella CP insertion is indicated by randomized assignment or protocol criteria, the device will be inserted percutaneously. Systemic anticoagulation will generally target an activated clotting time with approximately 160‐180 seconds during Impella CP support. A pulmonary artery catheter should be considered for hemodynamic monitoring when feasible. Mean arterial pressure of approximately 60‐65 mm Hg will be targeted, with vasopressors, inotropes, volume management, ventilation, and other supportive treatment individualized to the participant. At least one time of transthoracic echocardiography will be performed to check cardiac structure and function. PCI will be performed using standard techniques. In ST‐segment elevation myocardial infarction (STEMI), the culprit artery will be identified from the 12‐lead electrocardiogram and coronary angiography. In non‐ST‐segment elevation myocardial infarction (NSTEMI), identification will integrate the electrocardiogram, angiographic appearance, pre‐ and post‐PCI Thrombolysis In Myocardial Infarction (TIMI) flow, and echocardiography. If ambiguous, intravascular ultrasound or optical coherence tomography will be used to identify culprit lesion. Successful culprit‐lesion PCI is defined as final residual diameter stenosis <20% with TIMI flow grade 2 or 3. Complete revascularization should be considered when significant non‐culprit disease is present. Timing of non‐culprit PCI may be immediate or staged during the inde Xhospitalization at the operator's discretion. Coronary physiology such as fractional flow reserve may be used for visually estimated 50‐90% stenoses, whereas lesions =70% may proceed to PCI on angiographic grounds. Drug‐eluting stents, drug‐coated balloons, or conventional balloon angioplasty may be used as clinically appropriate. Guideline‐directed medical therapy, including dual antiplatelet therapy, will be prescribed. Shortened or de‐escalated dual antiplatelet therapy may be considered in patients at high bleeding risk. Choice of P2Y12 inhibitor, PCI access site, thrombus aspiration, glycoprotein IIb/IIIa inhibitor, and intravascular imaging is left to the operator. Because continuous anticoagulation is required during Impella s CONDITION: Diseases of the circulatory system PRIMARY OUTCOME: Composite of all‐cause death or refractory shock within 48 hours after index percutaneous coronary intervention SECONDARY OUTCOME: 24‐hour arterial lactate clearance All‐cause death Cardiac death Clinically significant Impella CP‐related hemolysis Composite of all‐cause death or refractory shock within 48 hours after inde Xpercutaneous coronary intervention Hospitalization for heart failure Impella CP malfunction, malposition, or device‐related cardiac or vascular injury Ischemic or hemorrhagic stroke Limb ischemia Major bleeding (Bleeding Academic Research Consortium [BARC] type 3 or 5 bleeding) Major vascular complications Refractory shock within 48 hours after inde Xpercutaneous coronary intervention Renal replacement therapy Sepsis or bloodstream infection Stent thrombosis Time from randomization to arterial lactate <2.0 mmol/L INCLUSION CRITERIA: 1) Age =19 years old 2) Acute myocardial infarction with culprit lesion requiring urgent percutaneous coronary intervention 3) Cardiogenic shock before culprit lesion percutaneous coronary intervention 4) Left ventricular ejection fraction =40% 5) Patients with persistent signs of shock despite medical therapy who are scheduled to undergo Impella CP insertion 6) Shock onset to randomization =12 hours