CREST

What is CREST?
Carotid
Revascularization
Endarterectomy vs.
Stenting
Trial

CREST is a study for people who have a narrowing their carotid artery, with or without symptoms such as a small stroke or a temporary stroke called a transient ischemic attack (TIA).

Why CREST?

Physicians want to find a better way to prevent strokes in people who have a
narrowing in their carotid artery. This research study will compare carotid endarterectomy, a common operation to prevent stroke, to a study procedure called carotid artery stenting.
Patients who agree to participate in the CREST study will receive either carotid endarterectomy or carotid artery stenting to treat the narrowed area in their carotid artery.

What is the purpose of this study?

Our physicians are trying to determine the safest way to prevent
strokes in people who have a partial blockage (or narrowing) of the
carotid artery.

Who may be involved in the study?

Adult men and women who have have moderate to severe narrowing of at least one of their carotid arteries.

Your carotid arteries will be examined by ultrasound or x-rays to see how much narrowing
has taken place. If one of your arteries is significantly narrowed and your physician
feels you are a good candidate, you may be eligible to participate.

Why do the carotid arteries get blocked?

The carotid arteries are the major vessels that supply blood

to the head, moving up both sides of the neck to the brain
and face. When blood flow to the brain is blocked, a serious
medical condition called a stroke or brain attack can occur.
The narrowing or blockage is often caused by a buildup of blood clots and fatty plaques (like cholesterol) in the fork of the carotid artery where it branches into the vessels that supply blood to the face and brain. The buildup of this fatty plaque is known as atherosclerosis, commonly called hardening of the arteries.

How do you find out if the carotid artery is blocked?

Two tests are available to CREST physicians to pinpoint exactly how much narrowing has
occurred in your carotid artery:

• Ultrasound, or carotid Doppler uses sound waves to measure the rate of blood flow through the artery.

• Cerebral angiography uses a contrast material injected into an artery (usually in the groin) to make the vessels in the head and neck visible in x-rays. Pictures are then taken and the amount of narrowing is measured.

How is carotid endarterectomy (CEA) performed?

• By a qualified surgeon using general or local anesthesia.
• The plaque is carefully removed.
• Blood flow to the brain is restored.

CEA has been the standard of care for the treatment of carotid stenosis for the last four decades.

How is carotid artery stenting (CAS) performed?

• By a qualified physician using local anesthesia.
• A mesh-like metal device called a stent is placed in the narrowed part of the artery to hold
it open.
• Blood flow to the brain is restored.

CAS is now approved by the Food and Drug Administration for patients considered high risk for the surgical procedure (CEA).

Will I have to take any medications as part of the study?

• If you have either procedure you will need to take aspirin daily for the duration of the
study.
• If you have the carotid artery stenting (CAS) procedure you will also need to take a medicine (clopidogrel or ticlopidine) daily for four weeks after the procedure.
• Your physician may ask you to take other medicines to control your blood pressure or
cholesterol.

What will happen in the study?

If you are interested in participating in the CREST study, you will be asked to come to
a local CREST center:
• For further tests
• To answer questions about your health
• To learn more about the study

If you choose to participate You will be assigned by chance (as in the flip of a coin) to receive either the CEA or the CAS procedure.

After the procedure, you will need to return to your CREST physician for follow-up
exams at:
• 1 month
• 6 months
• 12 months and annually thereafter.

You will also receive phone calls from the study nurse at:
• 3 months
• 9 months
• 15 months

• 18 months and annually thereafter.

There are 114 medical centers participating in this study. CREST enrolled 2,502 participants across the United States and Canada to be in this study. The physicians chosen to participate in CREST were selected because they have previous experience and are skilled at performing the procedures.

What are the benefits of taking part in this study?

The major goal of CREST is to compare the risks and benefits of the two treatments
(CEA and CAS) at medical centers around the US and Canada. During this study, you
will receive one of these two treatments. No personal benefit can be guaranteed to
you by your participation in this study. However, the information from this study will help
determine the best way to prevent strokes in other people like you.

What if my doctor referred me to a CREST surgeon for surgery?

Many patients are referred to a specialist for consideration of a specific procedure.

Your primary care doctor, internist, surgeon, cardiologist, or neurologist, may have referred you to a specialist for a carotid endarterectomy.

That specialist may be participating in this clinical trial which was designed to test the effectiveness of a common operation for carotid stenosis (called carotid endarterectomy) to a study procedure called carotid artery stenting.

Carotid endarterectomy is a common procedure proven effective through several clinical trials in reducing stroke for patients with significant narrowing of their carotid arteries. It is one of the most studied surgical procedures in North America and has been part of clinical practice for more than 40 years. The risks are very low when an experienced, well-qualified surgeon performs the procedure. This procedure is considered the standard of care for carotid stenosis. Only highly qualified surgeons with a very low rate of complications are selected to participate in CREST.

Carotid artery stenting is a relatively new procedure that is less invasive than carotid endarterectomy. The Food and Drug Administration (FDA) has recently approved it for patients who are considered too high-risk for the surgical procedure. Only highly qualified interventionalists with a very low rate of complications are selected to participate in CREST.

Stenting has not yet been approved for patients who are considered a low to moderate surgical risk and for whom carotid endarterectomy has been proven effective and safe.

CREST is a trial designed to determine if stenting is appropriate for patients like you.

Teamwork is very important to CREST and the physicians in CREST will all work together with you and your primary care physician for your health.

What if my doctor referred me to a CREST interventionalist for a stent?

Many patients are referred to a specialist for consideration of a specific procedure.

Your primary care doctor, internist, surgeon, cardiologist, or neurologist, may have referred you to this specialist for a carotid artery stent.

Stenting has not yet been approved for patients who are considered a low to moderate surgical risk and for whom carotid endarterectomy has been proven effective and safe.

CREST is a trial designed to determine if stenting is appropriate for patients like you.

Teamwork is very important to CREST and the physicians in CREST will all work together with you and your primary care physician for your health.

Ask your doctor

Being in CREST will mean that you, your primary care doctors, and the CREST study doctors will all work together for your health.

If you are interested in participating in CREST, contact the physician or study coordinator at your local center to discuss your options.