Effects of aSPIrin Versus Aspirin Plus Low-dose RIvaroxaban on Carotid aTherosclerotic Plaque Inflammation

Inclusion Criteria: * Men or women at least 18 years of age inclusive * Asymptomatic Carotid Artery Disease (diameter stenosis, 20-80%) * Inclusion criteria for the COMPASS trial (stable Peripheral Artery Disease(PAD); or stable Coronary Artery Disease(CAD) with 1 of age over 65 years, or age \<65 years plus atherosclerosis less than 2 vascular beds or less than 2 additional risk factors) * FDG Postron Emission Tomography(PET)/Computed tomogrphy(CT) shows hot uptakes at carotid artery (with or without hot uptake at ascending aorta) * The patient or guardian agrees to the study protocol and the schedule of clinical and FDG Postron Emission Tomography(PET)/Computed tomogrphy(CT) follow-up, and provides informed, written consent, as approved by the Institutional Review Board/Ethical Committee. Exclusion Criteria: * Patients treated with carotid endarterectomy or stent placement * Contraindications to rivaroxaban or aspirin. * Stroke in 1 month or any hemorrhagic or lacuna stroke * Need for dual antiplatelet therapy or oral anticoagulant therapy * Severe left ventricular dysfunction (ejection fraction \< 30%) * Any clinically significant abnormality identified at the screening visit, physical examination, laboratory tests, or electrocardiogram which, in the judgment of the Investigator, would preclude safe completion of the study. * Hepatic disease or biliary tract obstruction, or significant hepatic enzyme elevation (alanine aminotransferase(ALT) or aspartate aminotransferase…