February 28, 2010
Choice Between Stroke-Prevention Procedures Should Be Influenced by Patient Age
Two stroke-prevention procedures are safe and equally beneficial for men and women at risk for stroke, but the effectiveness does vary by age, say researchers at the University of Alabama at Birmingham (UAB) in collaboration with other North American stroke investigators.
In findings reported Feb. 26 at the International Stroke Conference in San Antonio, Texas, the researchers say physicians now have better information when tailoring their treatment plans for patients at risk for stroke. The study is called the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST).
Stroke, the third leading cause of death in the nation, 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.
CREST compares endarteroctomy, a surgical procedure to clear blocked blood flow and prevent stroke, with carotid stenting, a newer procedure that involves threading a stent and expanding a small protective device in the artery to widen the blocked area and capture dislodged plaque.
The overall safety and efficacy of the two procedures essentially is the same with equal benefits for men and women, for patients who previously have had a stroke and for those who had not, researchers say. The most notable finding was the role of patient age in accounting for differences in comparing the two prevention procedures, says George Howard, Dr.PH., chair of biostatistics in UAB's School of Public Health and a CREST co-investigator.
"The fascinating finding is that in young people, say age 69 and younger, the stenting is better than the surgery. The younger the patient, the better stenting works," Howard says. "In contrast, in older people, defined as greater than age 70, the surgery is better than the stenting, and the benefits are greater as the age of the patient increases."
CREST is one of the largest randomized stroke-prevention trials in history, involving 2,502 patients at 117 centers in the United States and Canada during a nine-year period. It is funded by the National Institute of Neurological Disorders and Stroke (NINDS) and led by Thomas G. Brott, M.D., of the Mayo Clinic in Jacksonville, Fla. Twenty-one CREST patients are enrolled in Alabama under the medical direction of William D. Jordan, M.D., chief of vascular surgery at UAB.
"The magnitude of the operation and the stent procedure is really about the same because even though it seems minimally invasive to use a stent, the surgical procedure really isn't that invasive, so most patients can tolerate either procedure," Jordan says. "We counsel our patients on which one to do based upon a lot of factors, including their age, their overall medical condition, and actually about the anatomy of the stenosis, about where it is, how severe it is, and what the plaque morphology is."
"The CREST trial provides doctors and patients with much needed risk/benefit information to help choose the best carotid procedure based on an individual's health history," says Walter J. Koroshetz, M.D., deputy director of NINDS. "This personalized decision-making should translate into improved patient outcomes."
Because people with carotid atherosclerosis also usually have atherosclerosis in the coronary arteries that supply the heart, the CREST trial tracks the rate of heart attacks, in addition to stroke and death.
In CREST, approximately half of the 2,502 patients had recent symptoms due to carotid disease such as a minor stroke, often called a transient ischemic attack (TIA), indicating a high risk for future stroke. The other half of patients had no symptoms but was found to have narrowing of the carotid artery on one of a variety of tests assessing narrowness and plaque.
CREST investigators did see more heart attacks in the surgical group, 2.3 percent compared to 1.1 percent in the stenting group, and they did see more strokes in the stenting group, 4.1 percent versus 2.3 percent for the surgical group in the weeks following the procedure. Overall the study found a lower stroke rate following surgery and a lower heart-attack rate after stenting a year after their procedure. The average age of CREST patients is 69.
NINDS is committed to long-term follow-up of CREST patients to learn how best to prevent stroke. Partial funding for the study is supplied by Abbott, of Abbott Park, Ill., the maker of the stents.
Others from UAB involved in the study are Virginia Howard, Ph.D., an associate professor of epidemiology, and Jenifer Voeks, Ph.D., an assistant professor of epidemiology, both in the School of Public Health. Also involved are researchers at Lenox Hill Hospital in New York; Oregon Health Science University in Portland; Central Baptist Hospital in Lexington, Ky.; Hop de L'Enfant Jesus in Quebec City, Canada; University of Medicine and Dentistry of New Jersey in Newark; University of Maryland in Baltimore; Harvard Clinical Research Institute in Boston; University of California, Los Angeles.
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