The objective of this imaging substudy of RESTORE trial is to demonstrate the superiority of drug-coated balloon (DCB) treatment on non-flow limited vulnerable plaque as compared to guideline-directed medical therapy (GDMT) in improving plaque stabilization in patients with acute coronary syndrome.

The present study is an integrated imaging substudy of randomized, controlled and intervention trial of preventive drug-coated balloon angioplasty in vulnerable atherosclerotic plaque (RESTORE). The RESTORE Imaging trial will equally enroll from the DCB arm and GDMT arm to at least 180 consecutive individuals to validate the superiority of drug-coated balloon (DCB) treatment on non-flow limited vulnerable plaque as compared to guideline-directed medical therapy (GDMT) in enlarge luminal dimensions.

Inclusion Criteria:

1. Subjects must be between 18 and 80 years of age
2. Subject must present with acute myocardial infarction or unstable angina planned for PCI
3. Successful stent implantation (i.e., residual stenosis less than 20%) must be done in culprit lesions and any lesions with ischemia evidence (e.g., QFR equal or less than 0.8)
4. Subject must have at least one native non-culprit lesion with visually estimated stenosis of 40-80% and QFR >0.8
5. Target lesion must have a visually estimated diameter of 2.0-4.0 mm and length of ≤ 50 mm
6. Target lesion must have any two of the intravascular imaging criteria of PB >65%, MLA <3.5 mm^2 (OCT) or 4.0mm^2 (IVUS), FCT <75 μm, or maximal lipid arc >180°
7. Subject must provide written informed consent before any study-related procedure

Exclusion Criteria:

1. Subject has known hypersensitivity or contraindication to any of the study drugs (including all asprin, P2Y12 inhibitors, one or more components of the study devices, including paclitaxel, etc) that cannot be adequately pre-medicated
2. Subject is receiving immunosuppressant therapy or has known immunosuppressive or severe autoimmune disease that requires chronic immunosuppressive therapy (e.g., human immunodeficiency virus, systemic lupus erythematosus, etc.)
3. Hypotension, shock, or need for mechanical support or intravenous vasopressors;
4. Creatinine clearance ≤30 ml/min/1.73 m^2 (as calculated by MDRD formula for estimated GFR)
5. Left ventricular ejection fraction<30% by the most recent imaging test within 30 days before procedure (echo, MRI, contrast left ventriculography or others)
6. Life expectancy <2 years for any
7. Subject is currently participating in another investigational drug or device clinical study that has not yet completed its primary endpoint
8. Presence of other anatomic or comorbid conditions, or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical investigation or to comply with follow-up requirements, or impact the scientific soundness of the clinical investigation results.
9. The target lesion is located within 10 mm of the proximal or distal of stent
10. The target lesion cannot be in the left main coronary artery
11. The target lesion is located in a bifurcation lesion (i.e., the diameter of the branch vessels is >2 mm with >50% of stenosis)
12. The target lesion is located in severe calcification or tortuosity of vessels
13. The target lesion involved in the ostium of LAD, LCX or RCA (within 3 mm of the ostium)
14. The target lesion is located within the bypass graft artery