This study is a prospective, multicenter, open-label, non-inferiority, randomized controlled trial. A total of 2,000 patients with STEMI (<24 hours or 7-14 days) or NSTEMI will be recruited from at least 20 centers in China. Eligible patients must have residual DS < 70% at the culprit lesion assessed by QCA, with optional thrombus aspiration, and TIMI flow of grade 3. Patients will be randomly assigned in a 1:1 ratio to the experimental group or the control group. The planned enrollment period is 36 months, and all patients will be followed up for at least 12 months after randomization, with continued follow-up until the end of the study. The primary outcome is the first occurrence of TLF after randomization, defined as the composite of cardiovascular death, target vessel myocardial infarction, ischemia-driven target lesion revascularization. The study aims to verify whether guideline-recommended standard medical therapy is non-inferior to DES implantation combined with guideline-recommended standard medical therapy in AMI patients with non-severe coronary artery stenosis.

A total of 120 participants (60 in the experimental group and 60 in the control group) enrolled at the Second Affiliated Hospital of Harbin Medical University were included in the functional substudy. Using Abbott Pressure Wire™X pressure wire test functional indicators, and explore the incidence of coronary microvascular dysfunction (CMD) as assessed by the index of microcirculatory resistance (IMR) in two groups, and its impact on the rate of the composite endpoint of all-cause death and heart failure readmission occurring for the first time within 12 months.

Inclusion Criteria:

1. Male or female patients aged ≥18 years and ≤75 years;
2. Diagnosis of type 1 AMI, including STEMI (onset <24 hours or 7-14 days) or NSTEMI;
3. 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);
4. Reference diameter of the culprit lesion >2.5 mm and ≤4.0 mm;
5. Patients or a legally authorized representative must provide written Informed Consent prior to any study related procedure.

Exclusion Criteria:

1.Clinical exclusion criteria:

1. Severe cardiac dysfunction (Killip/NYHA class ≥ 3) or LVEF < 30%;
2. Cardiopulmonary resuscitation (CPR) performed at the onset of AMI;
3. Persistent hemodynamic or cardiac electrical instability after TIMI flow restoration;
4. Contraindication to antithrombotic drugs, or concurrent hemorrhagic diseases such as peptic ulcer or coagulation disorders;
5. Contraindication to contrast;
6. 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);
7. Active liver disease, defined as known infectious, neoplastic, or metabolic liver lesions, with ALT and AST >3× upper limit of normal (ULN);
8. Previous history of CABG or PCI for the culprit lesion;
9. Patients with other concurrent severe diseases and an expected life expectancy of <1 year;
10. Pregnant or lactating women. Women of childbearing potential must use effective contraceptive measures during the study treatment period;
11. Inability to comply with the study protocol or other conditions deemed unsuitable for study participation by the investigator.

2.Imaging exclusion criteria:

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

3.Functional sub study:

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

Outcomes assessor-blinded