This retrospective cohort study evaluates cardiovascular events directly related to treated coronary arteries in patients with stable multivessel coronary artery disease. Outcomes in patients undergoing coronary artery bypass grafting or percutaneous coronary intervention will be compared with those receiving optimized medical therapy alone. This study aims to improve understanding of how different treatment strategies impact long-term vessel-related outcomes in patients with stable multivessel coronary artery disease.

Previous studies evaluating coronary revascularization strategies have relied on broad composite endpoints, which may include events unrelated to the treated vessel. This study focuses on vessel-related outcomes, specifically non-fatal myocardial infarction and cardiac death attributable to the treated coronary artery. Patients were selected from the MASS (Medicine, Angioplasty, or Surgery Study) database at a single tertiary center. By analyzing vessel-specific events, this study aims to provide a more accurate assessment of the long-term impact of different treatment strategies in stable multivessel coronary artery disease.

Inclusion Criteria:

• Patients with stable multivessel coronary artery disease, defined as ≥70% stenosis in at least two major epicardial coronary arteries, with documented myocardial ischemia and clinical indication for surgical, percutaneous, or medical treatment.

Exclusion Criteria:

• Patients with limited life expectancy, severe left ventricular dysfunction (ejection fraction <35%), recent acute coronary syndrome, recent revascularization procedures, significant valvular disease, chronic kidney disease (creatinine ≥2.0 mg/dL), active malignancy, or inability to complete long-term follow-up.

Adult patients with stable multivessel coronary artery disease and documented myocardial ischemia, selected from the MASS (Medicine, Angioplasty, or Surgery Study) database at a single tertiary academic center.

Individual participant data will not be shared publicly because this study is based on a retrospective institutional database with data ownership governed by institutional policies and local data protection regulations. De-identified data may be made available upon reasonable request, subject to approval by the investigators and the institutional ethics committee.