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 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.
An echocardiogram (ultrasound of the heart) uses sound waves to image the carotid arteries.
A gel is applied to the area of the neck to be imaged and a small handheld ultrasound probe
is held against the neck to take the pictures.
Participants return after 2 years for a second set of tests.
Under the general hypothesis that atherosclerosis is a systemic disease; the purpose of this
protocol is to compare coronary artery atherosclerotic abnormalities with carotid artery
abnormalities. This is an NHLBI sponsored sub study to the Pfizer sponsored trial comparing
atorvastatin or the combination of atorvastatin/CETP inhibitor as treatments for patients
with coronary heart disease. The primary study is a multicenter, randomized, double blind,
active-controlled study which uses intracoronary ultrasound to measure coronary plaque
volume during the course of treatment. The scientific value of the NHLBI sub study will be
the comparison of atherosclerotic abnormalities in two different vascular beds, the coronary
artery and the carotid arteries. This study will examine correlations between invasive
coronary measurements by intravascular ultrasound (IVUS), with 2-dimensional measurements of
wall thickness by carotid intimal medial wall thickness (IMT), and with 3-dimensional
measurements of carotid wall volume by MRI and 3D ultrasound. Secondary analysis will probe
whether carotid plaque characteristics can predict atheroma regression. Secondary analysis
will also assess the ability of noninvasive carotid measures to predict the degree of
coronary regression determined in the coronary arteries by IVUS. It is important to note
that the NHLBI study design remains blinded to the treatment group a subject is enrolled in
since the sample size for a single center study is too small to detect the conservatively
estimated additional benefit of combination atorvastatin/CETP inhibitor treatment over the
already effective atorvastatin alone. Thus, the NHLBI sub study is primarily a
pathophysiological study correlating carotid and coronary atherosclerotic changes as well as
a technological comparison of IVU, carotid IMT, and carotid vessel wall volume by MRI. If
successful, this study could provide the framework for following treatment trials of this
nature with noninvasive tools, either ultrasound or MRI, in place of the accurate but
Patients will be a subset of patients participating in the multicenter IVUS protocol.
Willingness to travel to the NIH to participate in the NHLBI MRI/IMT study.
Brain aneurysm clips
Implanted active medical devices (neural stimulators, cochlear implants, insulin pumps,
Allergy to gadolinium based contrast agents (only excludes the gadolinium portion of the