Efficacy and Safety of Aspirin in Patients With Chronic Coronary Syndromes Without Revascularization

Inclusion Criteria: * Patients with chronic coronary syndromes with ≧50% diameter stenosis in one or more major coronary vessels/major branches on coronary CT or coronary angiography but not eligible for coronary revascularization * Patients for whom consent can be obtained Exclusion Criteria: * Patients with history of acute coronary syndromes (ACS) * Patients with history of percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) * Patients with left main trunk stenosis (≥50%) * Patients for whom aspirin administration is mandatory * Patients undergoing antithrombotic therapy other than aspirin * Patients with atrial fibrillation * Patients with history of stroke within six months * Patients scheduled for major surgical procedures that will require aspirin discontinuation * Patients with contraindication of aspirin * Patients expected to have a prognosis of 1 year or less due to comorbidities * Women of child-bearing potential or women who have a positive pregnancy test at enrolment or randomization * Patients who are judged by attending physicians to be inappropriate to participate in this study