Overview

The aim of this clinical trial is to explore the optimal preventative treatment strategy for non-flow-limiting vulnerable plaques. The main question it aims to answer is:

Can interventional therapy further improve the outcome of non-flow-limiting vulnerable plaques on top of optimal pharmacologic therapy?

Researchers will randomly assign patients who meet the inclusion criteria to preventative intervention plus optimal drug therapy (experimental group) or optimal drug therapy alone (control group).

Participants will:

Assigned to the control group: optimized drug therapy consisting of lifestyle improvement and intensive drug therapy including high-dose statin or other therapy to achieve target levels (low-density lipoprotein cholesterol \<1.4 mmol/L and decreased by 50% compared to the baseline). Lifestyle improvement and risk factor management included smoking cessation, nutritional optimization, physical activity, compliance with prescribed medications, and control of diabetes and hypertension.

Assigned to the experimental group: all non-flow-limiting vulnerable plaques were treated with conventional second-generation drug-eluting stents. After the procedure, participants received dual antiplatelet therapy for about 12 months as well as other medications in the control group.

Eligibility

Inclusion Criteria Clinical Inclusion Criteria 1. Males or non-pregnant females aged 18-80 years 2. Clinically diagnosed with acute coronary syndrome (including unstable angina, ST-segment elevation myocardial infarction, and non-ST-segment elevation myocardial infarction) 3. Patients willing and able to sign a written informed consent form Angiography, QFR, and OCT Inclusion Criteria

1. Successful completion of angiography, QFR, and OCT examinations
2. Successful treatment of all culprit lesions and flow-limited lesions (QFR ≤ 0.8)
3. Reference vessel diameter between 2.5-4.0 mm on imaging assessment
4. Lesion length ≤40 mm
5. At least one significant stenosis (diameter reduction \>50%) demonstrated by angiography, with QFR \>0.80 and OCT-defined TCFA (fibrous cap thickness \<65μm, lipid arc \>90°)

Exclusion Criteria Clinical Exclusion Criteria

1. Patients with contraindications to dual antiplatelet therapy (DAPT) or planning to discontinue DAPT within one year
2. Patients with other major illnesses and a life expectancy \<2 years
3. Patients scheduled for cardiac surgery or major non-cardiac surgery
4. Women who are breastfeeding, pregnant, or planning pregnancy during the study
5. Patients with severe heart failure (NYHA class III-IV or Killip class III-IV or left ventricular ejection fraction \<35%)
6. Patients with estimated glomerular filtration rate \<30 mL/(min·1.73 m²)
7. Patients with allergy to contrast agents or DES drugs
8. Patients currently enrolled in other clinical studies Angiographic Exclusion Criteria

1\. Patients for whom CABG is the preferred treatment 2. Target lesion is a previously stented lesion 3. Target lesion is a post-bypass lesion 4. Target lesion is a heavily calcified or angulated lesion 5. Target lesion requires dual-stent technique 6. Target lesion is a left main coronary artery lesion.