Innate Immune Cell Phenotypes and Early Fibrotic Repair in Acute Myocardial Infarction

This study will enroll 50 patients with ST-segment elevation myocardial infarction (STEMI). Peripheral blood will be collected from these patients for immune cell subset analysis, serum cytokine evaluation, and neutrophil sorting for transcriptome sequencing. At 1 week after admission, cardiac magnetic resonance (CMR) will be performed to evaluate the myocardial salvage index, area of late gadolinium enhancement (LGE), microvascular obstruction (MVO), extracellular volume (ECV), and left ventricular ejection fraction (LVEF).

Primary outcomes

• Major cardiac adverse outcome [At 12 months after enrollment]: The composite endpoint included cardiac death, non-fatal myocardial infarction, and rehospitalization for angina.

Secondary outcomes

• Cardiac remodeling measured by CMR [At 1 week after admission]: CMR will be performed to evaluate the cardiac fibrosis defined as area of late gadolinium enhancement (LGE).

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

\---- Age > 18 and ≤ 80 years old

\- Patients with acute STEMI within 12 hours of symptom onset who are planned to receive PPCI

Exclusion Criteria:

* Prior revascularization
* Known allergy to gadopentetate dimeglumine contrast agent
* Pregnancy or planned pregnancy within the next 6 months
* Life expectancy < 1 year
* Metallic implants or claustrophobia that precluded MRI
* Severe COPD or inability to hold breath for MRI
* Severe hepatic or renal dysfunction (ALT > 5×ULN or eGFR < 15 mL/min/1.73 m²)