Mayo Clinic participating in major stroke prevention trial

Thursday, July 17, 2003

JACKSONVILLE, Fla., July 17, 2003 — Patients are now being enrolled here in a research study comparing carotid endarterectomy, a common operation to prevent stroke, to an experimental procedure, carotid artery stenting. The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST), is supported by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health.

Mayo Clinic in Jacksonville is one of up to 60 medical centers that will be participating in the study that is seeking 2,500 participants across the United States and Canada.

Mayo will be enrolling qualified participants over the next three-four years, according to Dr. Thomas Brott, a neurologist at Mayo Clinic and CREST national co-principal investigator.

To qualify, participants must have a significant narrowing of one carotid artery with at least 50 percent blockage and have had either a small stroke or a temporary stroke called a transient ischemic attack.

Buildup of arteriosclerosis or plaque, commonly known as hardening of the arteries, occurs at the point where the carotid artery divides into the internal and external arteries. Patients with carotid artery disease may be at risk for stroke if particles of atherosclerotic plaque are dislodged from the carotid artery wall. As these particles travel through the blood stream they can block the vessels in the brain, preventing adequate blood flow and causing the condition known as stroke.

The study is a test of carotid endarterectomy compared to carotid stenting. Carotid endarterectomy is an operation in which doctors clean out and repair a main artery supplying blood to the brain, the carotid artery. The carotid arteries are on each side of the neck. Carotid artery stenting is a procedure where a metal device called a stent is placed in a narrowed part of the carotid artery to cover the plaque and hold the vessel open. Stents have been implanted for years in blood vessels of the heart, kidney and legs. The stenting procedures and carotid surgeries in CREST will only be performed by doctors who have demonstrated expertise in the procedures.

Dr. Albert Hakaim, a vascular surgeon and CREST local principal investigator, Dr. W. Andrew Oldenburg, or Dr. Robert Wharen will perform the endarterectomies. Dr. David Miller, a neuro-interventional radiologist at Mayo, heads the team that will perform the carotid artery stenting procedures.

Within the study, half the patients will receive a carotid stent and half will have carotid endarterectomy. Guidant Corporation is providing both experimental devices (the ACCULINK™ Carotid Stent System and the ACCUNET™ Embolic Protection System) being used in CREST.

Participants in the trial will also receive medical management to reduce their risk factors for stroke. These include: high blood pressure; obesity; diabetes; smoking; and a high-fat, high-cholesterol diet.

Since the late 1950s, endarterectomy has been performed in patients with or without symptoms of stroke or impending stroke. According to statistics from the American Heart Association and the American Stroke Association approximately 140,000 of these surgical procedures are performed each year.

However, the operation carries some risks, and many physicians have questioned whether it is better than less invasive carotid stenting for the same conditions. "If your doctor finds a blockage in your carotid artery, are your chances of avoiding a stroke better if you have a carotid stent?" asks Dr. Robert Hobson, II. Hobson is a professor of surgery and the director of the Division of Vascular Surgery, University of Medicine and Dentistry of New Jersey- New Jersey Medical School, and principal investigator for this North American study. Results from CREST may be able to answer this and other important questions regarding the treatment of carotid disease.

Brott says that about 35 percent of all strokes in the United States are caused by atherosclerosis; 15 percent, on the other hand, are caused by hemorrhage. The American Stroke Association classifies stroke as the third most common cause of death and the No. 1 cause of disability in adults.

Mayo Clinic neurologists Frank Rubino, James Meschia and Benjamin Eidelman are also participating in CREST.

For further information about the study, please contact Diana Partin, RN, at 953-8736.

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