Comparison of the Incidence of Major Cardiovascular Events Between the Combination of Percutaneous Intervention and Optimal Drug Therapy and the Optimal Drug Therapy Alone in Patients With Chronic Coronary Syndrome

Inclusion Criteria: * Patients aged 40 years or older * Patients suspected of having chronic coronary syndrome who have undergone coronary angiography and confirmed stenotic lesions * Patients with lesions suitable for stent insertion who have 50% or more visually estimated stenosis in major coronary arteries with a diameter of 2.5 mm or greater observed on coronary angiography, and who satisfy one or more of the following conditions: 1. Patients with stenosis of 70% or more confirmed via Quantitative coronary angiography (50% or more for the left main coronary artery) 2. Minimum lumen area (MLA) ≤ 4 mm² or plaque burden \>70% on intravascular ultrasound (IVUS) 3. MLA \<3.5 mm² or area stenosis (AS) \>65% on Optical Coherence Tomography (OCT) 4. The corresponding stenosis on localizing stress imaging using SPECT or PET When there is a significant focal ischemic deficit in the coronary artery region of the lesion and the total perfusion deficit (TPD) is ≥10% 5. Pressure wire-based fractional flow reserve (FFR) ≤0.80 * Patients who can verbally confirm their understanding of invasive physiological or imaging evaluations and the benefits, harms, and alternative treatments of coronary angioplasty using drug-eluting stents, and for whom the patient or their legal representative can submit a written consent form. Additional Criteria for nested RCT Studies * When heart rate control is deemed therapeutically important due to an accompanying increase in heart rate at rest or during symptomatic episodes. * When the use of beta-blockers is deemed clinically advantageous due to a history of myocardial infarction. * When beta-blockers can help control blood pressure and symptoms in cases of concomitant hypertension. * When there is a clinical situation requiring associated tachyarrhythmia or heart rate control. * When beta-blockers are deemed more appropriate due to a history of contraindications, intolerance, or side effects of calcium channel blockers. Exclusion Criteria: * Patients with Left Ventricular Ejection Fraction (LVEF) less than 35% * Patients with cardiogenic shock * Patients with pulmonary edema or heart failure unresponsive to standard treatment * Patients with unstable angina whose symptoms persist despite maximal drug therapy * Patients with a history of ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), or unstable angina within the last 6 months * Patients with active bleeding * Patients with major bleeding of the gastrointestinal or urinary system within the last 3 months * Patients with coagulation disorders prone to bleeding (including heparin-induced thrombocytopenia) * Patients with hypersensitivity to or contraindications to the following drugs: Heparin, Aspirin, Clopidogrel, Prasugrel, Contrast media (Patients sensitive to contrast media are not excluded if the condition can be effectively prevented through pretreatment with steroids or diphenhydramine (e.g., flare-ups). * Patients for whom percutaneous coronary intervention (PCI) is contraindicated * Patients who have already undergone coronary artery bypass grafting (CABG) * Patients with in-stent restenosis in the target lesion * Patients with chronic total occlusion (CTO) in major coronary arteries * Patients with lesions having an FFR of less than 0.64 * Patients with coronary arteries that are anatomically unsuitable for both PCI and CABG * Patients with non-ischemic dilated cardiomyopathy or hypertrophic cardiomyopathy * Patients with severe valvular disease or those judged by the investigator to be likely to require valve surgery or percutaneous valve replacement during the study period * Patients with non-cardiac diseases, etc., with a life expectancy of less than one year or expected to have low treatment adherence (at the investigator's judgment) * Pregnant or breastfeeding patients * Other patients deemed by the investigator to be unsuitable for participation in the clinical trial Additional Criteria for nested RCT Studies * Significant bradycardia at rest, second-degree or higher atrioventricular block, or significant conduction disturbance * Bronchial asthma or clinically significant bronchospasmodic disease * Symptomatic hypotension * Variant angina as a main presentation * Other cases where the supervising investigator deems the use of beta-blockers medically inappropriate