Intravascular Imaging and Microvascular Obstruction

This study is a prospective, single-center, randomized controlled clinical trial. Ninety patients with anterior wall ST-segment elevation myocardial infarction (STEMI) who are planned for primary percutaneous coronary intervention (PCI) within 6 hours of symptom onset will be screened. Patients with inclusion criteria and without exclusion criteria will be randomized into three groups in a 1:1:1 ratio: OCT-guided group, 60 MHz HD-IVUS-guided group, and angiography-guided group after signing the informed consent form. Based on the lesion characteristics detected by imaging in each group, coronary revascularization will be performed for the culprit vessels of myocardial infarction. The TIMI myocardial perfusion frame count (TMPFC) values of the culprit vessels will be recorded immediately after PCI, and secondary prevention medications for myocardial infarction will be administered. Three days after the procedure, a 3.0T cardiac magnetic resonance imaging (MRI) with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) delayed enhancement (LEG) scan will be conducted to assess the microvascular obstruction (MVO) area. Patients will be followed in the outpatient clinic visit at 1 month (with a window period of XX days) after discharge, and a repeat cardiac MRI will be performed to determine the presence of MVO and the size of the myocardial infarction.