This observational study aimed to investigate the prognostic value of high-frequency QRS (HF-QRS) in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI), as well as its potential role in diagnosing microvascular dysfunction. The main question it aims to answer is:

1. Whether HF-QRS could serve as an effective tool for early identification of high-risk AMI patients and prognosis prediction;
2. Whether HF-QRS provides auxiliary diagnostic value for post-AMI microvascular dysfunction.

Participants underwent HF-QRS assessment and were prospectively followed for 1 year to record the incidence of major adverse cardiovascular events (MACE).

Inclusion Criteria:

• Aged 18 to 75 years (inclusive)

Diagnosed with acute myocardial infarction (AMI, including STEMI and NSTEMI) and underwent successful emergency PCI

Voluntarily participated and provided written informed consent

Exclusion Criteria:

• History of prior myocardial infarction or chronic heart failure

QRS duration >120 ms (including paced rhythm, WPW syndrome, bundle branch block, or left ventricular hypertrophy with repolarization abnormalities)

Structural heart disease (congenital heart disease, cardiomyopathy, aortic dissection, etc.)

Persistent atrial fibrillation or malignant arrhythmias

History of cerebral hemorrhage or ischemic stroke within 1 month

Prolonged cardiopulmonary resuscitation or requiring advanced life support (IABP/ECMO, etc.)

Scheduled for imminent surgery with anticipated inability to complete HF-QRS assessment

Other life-threatening conditions including: Severe hepatic or renal dysfunction;Uncontrolled systemic diseases;Hematologic disorders;Active infections;Malignancy with life expectancy <1 year Other investigator-determined exclusionary conditions:Pregnancy;Concurrent participation in other clinical trials

Refusal to participate in the clinical study

patients with acute myocardial infarction following percutaneous coronary intervention