Comparison of Clopidogrel Versus Ticagrelor Therapy for Atherosclerotic Plaque Inflammation

Inclusion Criteria: * Men or Women at least 18 years of age inclusive * Patients with acute coronary syndromes (unstable angina pectoris Braunwald class IB, IC, IIB, IIC, IIIB, IIIC, NSTEMI or STEMI) * FDG PET/CT shows at least 1 hot uptakes at carotid and or ascending aorta * The patient or guardian agrees to the study protocol and the schedule of clinical and FDG PET/CT follow-up, and provides informed, written consent, as approved by the appropriate Institutional Review Board/Ethical Committee of the respective clinical site. Exclusion Criteria: * Patients treated with carotid endarterectomy or stent placement * Chronic disease requiring treatment with oral, intravenous, or intra-articular corticosteroids (use of topical, inhaled, or nasal corticosteroids is permissible). * Untreated hyperthyroidism, or hypothyroidism * 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. * Evidence of congestive heart failure, or left ventricular ejection fraction \< 40%. * Significant renal disease manifested by serum creatinine \> 2.0mg/dL, or creatinine clearance of \< 40 ml/min (by Cockcroft-Gault method). * Hepatic disease or biliary tract obstruction, or significant hepatic enzyme elevation (ALT or AST \> 3 times upper limit of normal). * History of adult asthma manifested by bronchospasm in the past 6 months, or currently taking regular anti-asthmatic medication(s). * Unwillingness or inability to comply with the procedures described in this protocol. * Patient's pregnant or breast-feeding or child-bearing potential. * Type I Diabetes