We wish to see if the drug rosiglitazone, currently used in the treatment of type 2 diabetes, could be used as a new treatment for angina when compared with placebo in overweight subjects who do not have overt diabetes. The drug will be given for 3 months and the subjects will be have their angina tested, by way of exercise testing, angina quality of life questionnaire and 24-hour ECG monitoring before and after using the drug.

Chronic stable angina is a common manifestation of ischaemic heart disease. Current mechanical therapies (percutaneous coronary intervention and coronary artery bypass grafting) and pharmacological therapies (nitrates, calcium channel blockers, betablockers and potassium channel activators) main actions are to treat the end product of ischaemic heart disease on chronic stable angina, i.e. the flow limiting stenosis. We postulate that by treating insulin resistance, an upstream factor in the pathogenesis of ischaemic heart disease, we will improve angina by in turn improving endothelial function. We will attempt to demonstrate this by way of full bruce protocol exercise tolerance test, Seattle Angina Questionnaire and 24 hour ST segment analysis before and after treatment with the insulin sensitiser rosiglitazone for three months.

Inclusion Criteria:

• Chronic stable angina - to see if this improves
• Previous positive exercise tolerance test - to ensure that repeating it yields a result
• Disease not suitable for coronary intervention (Coronary artery bypass grafting or angioplasty) - so that best routine care is not withheld
• Do not have overt diabetes - work on this is being undertaken elsewhere
• Body mass index (BMI) greater than 25

Exclusion Criteria:

• Diabetes mellitus - see above
• Liver failure (ALT>70U/l, AST>80U/l)
• Renal failure (creatinine > 130mmol/l)
• Cardiac failure - rosiglitazone is contraindicated in those with NYHA 3 and 4 cardiac failure
• Physical disability - if it precludes treadmill testing
• Women of child bearing capacity
• Breast feeding mothers