• The subject, or their legal guardian, must have a clear understanding of the trial's design and treatment procedures. They must provide written informed consent before any trial-specific tests or procedures are conducted.

• Both male and female subjects aged ≥18 years.

• Subjects who have experienced an ACS and have undergone PCI for culprit lesions (either QFR or FFR \< 0.8) are eligible. ACS is defined as:

⁃ (1) Unstable angina (characterized by rest pain lasting between 5 and 30 minutes or worsening exertional angina accompanied by either transient ST segment depression or elevation, or angiography revealing visually estimated diameter stenosis of 90% or greater, or a ruptured plaque or thrombotic lesion), or (2) Non-ST elevation myocardial infarction, indicated by positive troponin levels consistent with the clinical syndrome and non-ST segment elevation, or (3) ST elevation myocardial infarction, indicated by positive troponin levels consistent with the clinical syndrome and ST-segment elevation.

⁃ 4\. Low-density lipoprotein cholesterol levels must meet the following criteria:

• Low-density lipoprotein cholesterol ≥70 mg/dL (≥1.8 mmol/L) in patients who have been on a stable high-intensity statin regimen for at least 4 weeks before enrollment.

• Low-density lipoprotein cholesterol ≥90 mg/dL (≥2.3 mmol/L) in patients who have been on a moderate or low-intensity statin regimen before enrollment.

• Low-density lipoprotein cholesterol ≥125 mg/dL (≥3.2 mmol/L) in patients who are statin-naïve or have not been on a stable statin regimen for at least 4 weeks before enrollment.

⁃ 5\. Subjects must have at least one culprit lesion for ACS in a major native coronary artery (diameter stenosis \>70% with a QFR or FFR\<0.8), and have at least one non-culprit vessel disease (diameter stenosis ≤70% with a QFR or FFR ≥0.8).