Multi-organ Imaging of Microvascular and Metabolic Function

Inclusion Criteria: * Adults aged 18 years and older * For patients with cardiovascular disease: Documented diagnosis of ischemic heart disease based on standard clinical, radiologic, and/or histopathologic criteria, as documented in the medical record; or a clinical nuclear cardiac stress PET test within 1 year. * For healthy subjects: No diagnosis of cardiometabolic disease, cancer, or other major disease within the past 5 years Exclusion Criteria: * Contraindications to PET due to: 1. Research-related radiation exposure exceeding current MGB Radiology Department guidelines (i.e., 50 mSv in the prior 12 months); 2. Inability to lie comfortably on the bed inside the scanner; 3. Body weight \> 300 lbs (weight limit of the scanner table); 4. Pregnancy or breastfeeding; * Individuals with fasting plasma glucose level of \>200 mg/dL; * Claustrophobia * Employed under the direct supervision of the PI conducting the research.