Grant: Operating Grant

Background: Despite significant advances in our understanding and treatment of heart disease, it remains the most important cause of early death and disability in well-off nations. The most common form of heart disease is coronary artery disease, which occurs when the main blood vessels that supply blood to the heart are blocked by cholesterol buildup. Narrowing of these heart vessels can lead to reduced blood flow and can result in decreased oxygen supply to the heart. If left untreated, this can lead to heart attack and even death. Aims: This study aims to investigate whether a new heart imaging technique is able to detect changes in the oxygen content of blood in the heart muscle. The new technique is called blood-oxygen-level dependent (BOLD) cardiac magnetic resonance imaging (CMR). We want to use this technique to take pictures of the oxygen content in the heart and therefore assess how severe any disease in the heart arteries may be. Methods: We want to study heart muscle oxygen levels by looking at people who have had a abnormal heart stress test and who have been booked to have a coronary angiogram (this is where dye is injected down the heart arteries and x-ray pictures taken). We will do 2 heart scans: one before or soon after the angiogram, and another scan 1 month later. By comparing the results from the scan with some special measurements made within the heart arteries at the time of the angiogram, we hope to show that the new heart scan can accurately tell us how narrowed the arteries are. Significance: Heart imaging techniques used to assess disease in the heart often require the use of contrast ("dye") and/or radiation. Also, all current methods do not measure oxygen in the heart muscle directly, but use indirect or substitute measures. By directly measuring the oxygen levels in the heart muscle, this new heart scan technique may improve our ability to diagnose heart disease and may mean that some people can avoid unnecessary procedures