Non-stenting Treatment Strategy for Acute Myocardial Infarction With Non-severe Stenosis(EROSION IV)

Inclusion criteria

• Male or female patients aged ≥18 years and ≤75 years;
• Diagnosis of type 1 AMI, including STEMI (onset <24 hours or 7-14 days) or NSTEMI;
• After coronary angiography (CAG) ± thrombus aspiration, TIMI flow in the culprit vessel is restored to grade 3 and maintained for at least 5 minutes, with diameter stenosis (DS) <70% at the culprit lesion (QCA);
• Reference diameter of the culprit lesion >2.5 mm and ≤4.0 mm;
• Patients or a legally authorized representative must provide written Informed Consent prior to any study related procedure.

Exclusion criteria

1.Clinical exclusion criteria:

• Severe cardiac dysfunction (Killip/NYHA class ≥ 3) or LVEF < 30%;
• Cardiopulmonary resuscitation (CPR) performed at the onset of AMI;
• Persistent hemodynamic or cardiac electrical instability after TIMI flow restoration;
• Contraindication to antithrombotic drugs, or concurrent hemorrhagic diseases such as peptic ulcer or coagulation disorders;
• Contraindication to contrast;
• Severe renal dysfunction [defined as eGFR ≤30 ml/min/1.73m² or Scr ≥2.0 mg/dL] without regular dialysis (patients with chronic renal insufficiency on regular dialysis may be considered for enrollment);
• Active liver disease, defined as known infectious, neoplastic, or metabolic liver lesions, with ALT and AST >3× upper limit of normal (ULN);
• Previous history of CABG or PCI for the culprit lesion;
• Patients with other concurrent severe diseases and an expected life expectancy of <1 year;
• Pregnant or lactating women. Women of childbearing potential must use effective contraceptive measures during the study treatment period;
• Inability to comply with the study protocol or other conditions deemed unsuitable for study participation by the investigator.

2.Imaging exclusion criteria:

• Non-culprit lesion with DS ≥70% or planned revascularization;
• Left main coronary artery lesion with DS ≥50%;
• Culprit lesion is a true bifurcation lesion requiring a two-stent strategy;
• Long lesion (planned stent length >60 mm);
• Culprit lesion with dissection, false lumen, or other conditions necessitating stent implantation;
• Target lesion has undergone pre-treatment (such as balloon dilation, rotational atherectomy, etc.).

3.Functional sub study:

• Individuals who are allergic to adenosine triphosphate (ATP) or any component in its preparations;
• Second and third degree atrioventricular block, sick sinus syndrome (without artificial pacemaker protectors);
• Patients with bronchial asthma.