Identification Of High-risk Coronary Plaques By Multimodal Intravascular Imaging

Inclusion Criteria: * Inclusion criteria for the clinical study: 1. Aged ≥18 years at enrollment, male or female; 2. Meets the diagnosis of acute coronary syndrome, including acute myocardial infarction and unstable angina. Acute myocardial infarction includes ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (non-STEMI). STEMI is defined as chest pain lasting at least 30 minutes, arriving at the hospital within 12 hours from the onset of symptoms, changes in the 12-lead ECG (ST-segment elevation \>0.1 mV in ≥2 consecutive leads or new left bundle branch block), and elevated cardiac biomarkers (troponin T/I). Non-STEMI is defined as ischemic symptoms without ST-segment elevation on ECG, accompanied by elevated cardiac biomarkers. Unstable angina is defined as chest pain lasting 5-30 minutes at rest, or worsening of exertional angina, and accompanied by one of the following: transient ST-segment depression or elevation; coronary angiography showing luminal narrowing ≥90% or plaque rupture or thrombotic lesions. 3. Planned to undergo coronary angiography and PCI treatment; 4. Hemodynamically stable and able to tolerate repeated intracoronary administration of nitroglycerin; 5. Capable of understanding the requirements of this study, willing to participate in the study, and have signed an informed consent form. * Imaging inclusion criteria: 1. Coronary angiography clearly shows that the patient has at least one non-culprit lesion with a visual assessment of diameter stenosis between 40-70%, and the operator believes that interventional treatment intervention is not temporarily necessary; 2. The site of the non-culprit lesion has not previously had a stent implanted. Exclusion Criteria: * Exclusion criteria for the clinical study: 1. Cardiogenic shock or hemodynamic instability; 2. History of coronary artery bypass grafting (CABG), or planned CABG; 3. Severe renal impairment (glomerular filtration rate \<30ml/min/1.73m²); 4. Life expectancy of less than 2 years; 5. Currently participating in other ongoing investigative device or drug studies that have not yet reached their primary endpoints. * Imaging exclusion criteria: The anatomical structure of the non-culprit lesion is not suitable for intravascular imaging catheter imaging (lesions at the left main trunk or right coronary artery ostium, severe calcification, chronic total occlusion, etc.).