Atherosclerosis in the Coronary and Carotid Arteries

This study will compare changes in atherosclerotic plaque in the coronary arteries (vessels on the surface of the heart that supply blood to the heart) with changes in the carotid arteries (vessels in the neck that supply blood to the brain) in patients enrolled in a Pfizer-sponsored treatment trial for coronary artery disease. Atherosclerosis is a buildup of fatty deposits (plaque) in arteries that can lead to blockage of the vessel, possibly resulting in heart attack or stroke. A major question in cardiovascular disease is how closely atherosclerotic changes in the coronary arteries correlate with changes in the carotid artery that occur with treatment. substudy of a Pfizer. Patients enrolled in the Pfizer trial comparing the effectiveness of the drug atorvastatin with a combination of atorvastatin and CETP inhibitor (a drug to increase HDL cholesterol levels) may be eligible for this substudy. Participants undergo magnetic resonance imaging (MRI) and ultrasound of the carotid arteries to measure the thickness of the vessels. The results are then compared with the coronary artery images obtained as part of the patient's evaluation for the Pfizer trial. MRI MRI scans use a powerful magnet with an advanced computer system and radio waves to produce accurate, detailed pictures of organs and tissues. During the scan the patient lies on a table in a narrow cylinder containing a magnetic field, wearing earplugs to muffle loud noises that occur with electrical switching of the magnetic fields. A medicine called gadolinium contrast may be injected into a vein during part of the scan to brighten the images. The scan takes about 30 to 90 minutes. An electrocardiogram (ECG) is done during the scan to monitor the heart's electrical activity. Patients who agree to undergo another MRI test are also imaged in a scanner that uses a stronger (3 Tesla) magnet. Ultrasound An echocardiogram (ultrasound of the heart) uses sound waves to image the carotid arteries. A gel is appli