Cardiovascular disease is the leading cause of death in Scotland and the Western World. Approaches to improve the identification of vulnerable or ruptured coronary atherosclerotic plaques are urgently needed to help risk stratification, to identify patients for intensive therapies, and to provide novel biomarkers for the development of anti-atherosclerotic drug interventions. Using positron emission tomography, we have recently shown that sodium 18-fluoride uptake holds major promise as a novel marker of plaque vulnerability and rupture. Here we wish to characterise coronary atherosclerotic plaque using 128-multidetector computed tomography combined with 18-fluorodeoxyglucose and sodium 18-fluoride positron emission tomography and Virtual histology-intravascular ultrasound in 80 patients with stable and unstable coronary artery disease. This has the potential to provide an innovative and highly valuable translational model with which to test novel therapeutic interventions targeted at reducing atheroma and plaque rupture. This could have major implications for the future treatment of cardiovascular disease.

Inclusion Criteria:

Age > or = 50 yrs. Patients with Acute coronary syndromes or stable coronary artery disease.

Exclusion Criteria:

Insulin dependent diabetes Inability or unwillingness to undergo computed tomography scanning Severe renal failure (serum creatinine >250 µmol/L or estimated glomerular filtration rate <30 mL/min) Known contrast allergy Inability to give informed consent. Females in child bearing age will undergo pregnancy test if pregnancy suspected.

Participation in other research studies requiring exposure to further radiation (over and above mentioned in this study).

The investigators will recruit two populations of 40 patients each. The first population will be patients with known stable coronary heart disease. They will have previously documented and angiographically proven coronary artery disease (≥70% luminal stenosis of a major epicardial vessel). The second population will be patients with a recent (within 30 days) acute myocardial infarction defined by the Universal definition of myocardial infarction. The culprit plaque will be defined according to the invasive coronary angiogram appearances, electrocardiogram and clinical features by two cardiologists blinded to the results of positron emission tomography.