This research will explore the association between blood serum renalase and microcirculation obstruction in patients with acute myocardial infarction (AMI) after primary percutaneous coronary intervention (PCI). The investigators aim to identify potential risk factors for microcirculation obstruction in AMI patients after PPCI.

Inclusion Criteria:

1. Age ≥ 18 years;
2. STEMI symptom onset time < 12 hours;
3. STEMI symptom onset time 12-48 hours with persistent ischemic symptoms, hemodynamic instability, or life-threatening ventricular arrhythmias;
4. High-risk NSTEMI;
5. Emergency PCI;
6. Voluntary informed consent.

Exclusion Criteria:

1. Non-obstructive acute myocardial infarction;
2. Severe chronic kidney disease (defined as estimated glomerular filtration rate < 20 mL/min per 1.73 m²);
3. Life expectancy < 1 year;
4. Pregnant or planning to become pregnant;
5. Emergency PCI failure.

The study population will include 200 patients diagnosed with acute myocardial infarction (AMI) who will undergo primary percutaneous coronary intervention (PCI) at the Third Xiangya Hospital of Central South University, from August 2024 to August 2025.