Patients with acute coronary syndrome (ACS) who have both high ischemic risk and high bleeding risk represent a challenging population following percutaneous coronary intervention (PCI), as prolonged dual antiplatelet therapy (DAPT) may reduce ischemic events but increases bleeding complications.This prospective, multicenter, randomized controlled study evaluates the safety and effectiveness of an optimized PCI and antiplatelet therapy strategy in ACS patients with moderate-to-high ischemic risk and high bleeding risk. Eligible patients will be randomized in a 1:1 ratio to either an experimental strategy consisting of intravascular ultrasound-guided implantation of a polymer-free drug-coated stent followed by one month of DAPT and subsequent single antiplatelet therapy, or a control strategy consisting of angiography-guided implantation of contemporary drug-eluting stents followed by standard 12-month DAPT.The primary hypothesis is that the experimental strategy will reduce the incidence of net adverse clinical events, defined as a composite of ischemic and bleeding outcomes, compared with conventional PCI and prolonged DAPT. Participants will be followed for 12 months after the index procedure.

This study is a prospective, multicenter, randomized controlled trial designed to evaluate an optimized revascularization and antiplatelet therapy strategy in patients with acute coronary syndrome (ACS) who present with both moderate-to-high ischemic risk and high bleeding risk.Eligible patients aged 18 years or older who meet Academic Research Consortium-High Bleeding Risk criteria and have an OPT-CAD score of 90 or higher will be randomized in a 1:1 ratio to an experimental group or a control group. Patients in the experimental group will undergo intravascular ultrasound-guided PCI with implantation of a polymer-free drug-coated coronary stent, followed by one month of dual antiplatelet therapy consisting of aspirin and a P2Y12 inhibitor, and subsequent single antiplatelet therapy. Patients in the control group will undergo angiography-guided PCI with implantation of contemporary drug-eluting stents and receive standard dual antiplatelet therapy for 12 months.Clinical follow-up will be conducted at discharge and at 30 days, 6 months, and 12 months after the index procedure. Clinical data collected during follow-up will include ischemic events, bleeding events, antiplatelet therapy use, and adverse events.The primary endpoint is the incidence of net adverse clinical events at 12 months, defined as a composite of ischemic and bleeding outcomes, including cardiac death, myocardial infarction, ischemic stroke, definite stent thrombosis, clinically driven target vessel revascularization, or bleeding events classified according to the Bleeding Academic Research Consortium criteria. Secondary endpoints include clinically relevant bleeding and ischemic outcomes.Study data will be collected using a centralized electronic data capture system with predefined data validation rules and audit trails. Data quality will be ensured through investigator training, standardized operating procedures, automated range and consistency checks, and regular site monitoring with source data verification against source documents. A predefined data dictionary will describe all registry variables, including definitions, coding information, and clinically relevant ranges where applicable. Missing data will be addressed according to a prespecified statistical analysis plan.The planned sample size is 468 participants, providing adequate statistical power to detect differences in the primary endpoint using an intention-to-treat analytical approach.

Inclusion Criteria:

• Aged ≥ 18 years old
• ACS patients with high bleeding risk (meeting the ARC-HBR criteria)
• Moderate-to-high ischemic risk (OPT-CAD score ≥ 90)
• Predicted by the investigator to be able to tolerate 12 months of DAPT
• Voluntarily participate and sign the informed consent form, and be willing to receive the designated follow-up of this trial at specific time points
• Coronary artery lesions are primary and in-situ coronary artery lesions
• Target lesion diameter stenosis ≥ 70% or ≥ 50% (visual estimation) accompanied by evidence of myocardial ischemia

Exclusion Criteria:

• Patients with known allergy or contraindication to P2Y12 inhibitors, aspirin, or contrast agents
• Patients planning to undergo surgical intervention within 12 months
• Left Ventricular Ejection Fraction (LVEF) < 35%
• Patients with contraindications to PCI
• Patients with a history of substance abuse (alcohol, cocaine, heroin, etc.), or with an expected life expectancy of less than 1 year
• Subjects with poor compliance or judged by the investigator to be unsuitable for participating in the study
• Female patients who are planning to be pregnant or are pregnant/lactating, and male patients planning to impregnate
• Chronic total occlusion lesions
• Lesions involving the left main coronary artery
• Severe calcified and tortuous lesions