Fred Weaver, M.D., chief of the Division of Vascular Surgery at the Keck School of Medicine of USC, and the principal investigator of the study at USC.

A major study of people at risk for stroke, conducted in part at USC University Hospital, showed that two medical procedures designed to prevent future strokes are safe and effective overall. Physicians will now have more options in tailoring treatments for their patients at risk for stroke.

In the trial of 2,502 participants, carotid endarterectomy (CEA), a surgical procedure to clear blocked blood flow and considered the gold standard prevention treatment, was compared to carotid artery stenting (CAS), a newer and less invasive procedure that involves threading a stent and expanding a small protective device in the artery to widen the blocked area and capture any dislodged plaque. The study appears today in the online first edition of the New England Journal of Medicine.

One of the largest randomized stroke prevention trials ever, the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) took place at the University of Southern California along with 116 other centers in the United States and Canada, over a nine-year period. CREST compared the safety and effectiveness of CEA and CAS in patients with or without a previous stroke. The trial was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health, and led by investigators at Mayo Clinic, Jacksonville, Fla., and the University of Medicine and Dentistry of New Jersey in Newark.

"The results of this landmark trial provide important information on the relative safety and efficacy of carotid endarterectomy and carotid stenting to prevent stroke, which will be used for many years to come in patients with carotid stenosis," said Fred Weaver, M.D., chief of the Division of Vascular Surgery at the Keck School of Medicine of USC, and the principal investigator of the study at USC.

USC enrolled 18 patients in the study, which was conducted as a collaboration between the divisions of Vascular Surgery, Neurosurgery and Neurology. USC was also the leading center in minority enrollment.

The overall safety and efficacy of the two procedures was largely the same with equal benefits for both men and for women, and for patients who had previously had a stroke and for those who had not. However, when the investigators looked at the numbers of heart attacks and strokes, they found differences. The investigators found that there were more heart attacks in the surgical group, 2.3 percent compared to 1.1 percent in the stenting group; and more strokes in the stenting group, 4.1 percent versus 2.3 percent for the surgical group in the weeks following the procedure.

The study also found that the age of the patient made a difference. At approximately age 69 and younger, stenting results were slightly better, with a larger benefit for stenting, the younger the age of the patient. Conversely, for patients older than 70, surgical results were slightly superior to stenting, with larger benefits for surgery, the older the age of the patient.

Stroke, the third leading cause of death in the United States, is caused by an interruption in blood flow to the brain by a clot or bleeding. The carotid arteries on each side of the neck are the major source of blood flow to the brain. The buildup of cholesterol in the wall of the carotid artery, called atherosclerotic plaque, is one cause of stroke. Because people with carotid atherosclerosis also usually have atherosclerosis in the coronary arteries that supply the heart, the CREST trial tracked the rate of heart attacks, in addition to stroke and death.

One of the strengths of the study, according to investigators, is that CREST was conducted in a variety of real world settings, including large and small public and private hospitals. Physicians had to demonstrate a high degree of proficiency and safety in order to participate in the trial. The study found no significant differences in the outcomes, no matter what type of medical specialist performed the stenting procedure, including cardiologists, neuroradiologists, interventional radiologists, vascular surgeons and neurosurgeon.

"The CREST trial was a large, complex undertaking that will provide the medical community with important information on the comparative effectiveness of these two procedures. NINDS is committed to long-term follow up of this group of patients, which will help us learn even more about how best to prevent stroke," said Story Landis, Ph.D., NINDS director.

Partial funding for the study was supplied by Abbott, of Abbott Park, Ill., the maker of the stents.

Brott,TG et al., Stenting Compared to Endarterectomy for Treatment of Carotid Artery Stenosis, New England Journal of Medicine, online first edition May 26, 2010.