Stents May Be Effective Weapon Against Stroke
One study finds they are equal to artery-clearing surgery, but another trial does not
FRIDAY, Feb. 26, 2010 (HealthDay News) -- Both stents and conventional surgery appear to be equally effective in preventing strokes in people whose carotid arteries are blocked, according to research presented Friday at the American Stroke Association's annual meeting in San Antonio.
However, a second stents-versus-surgery trial, published Thursday in The Lancet, seemed to give surgery better marks, so the jury may still be out on which approach is better in shielding patients from stroke.
"I think both procedures are excellent and I'm happy to say we have two good options to treat patients," said Dr. Wayne M. Clark, professor of neurology and director of the Oregon Stroke Center, Oregon Health Sciences University in Portland, and a co-author of the stroke association study.
"I think the [ASA] trial is really a positive for both stenting and surgery," said Dr. Craig Narins, associate professor of medicine at the University of Rochester Medical Center in New York, who was not involved with the study. "I think this is going to change the way that physicians look at carotid artery disease."
That study, the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), was funded by the U.S. National Institute of Neurological Disorders and Stroke and Abbott, which makes the carotid stents.
"There has been a lot of skepticism about the ability of stenting to equal surgery and this trial pretty nicely shows that it does equal it overall," Narins added.
But the findings from CREST need to be squared with the second trial, the International Carotid Stenting Study (ICSS). That European trial found that surgery remained superior to stenting in the short-term, and stenting did not appear to be as safe as surgery.
"They're very similar studies, although the European [ICSS] study didn't use embolic protection devices which are the standard of care in the U.S. That could have skewed the results," Narins said. Embolic protection devices are tiny parachute-like devices placed downstream from a stent to safely catch dislodged materials.
Nevertheless, he added, "nothing is going to change overnight. It's a sea change because surgery has been the standard of care for so long. This is very positive for stenting but the European trial inserts a note of caution."
In carotid endarterectomy (CEA) surgery, doctors scrape away the built-up plaque that is causing a narrowing of the artery supplying blood to the brain.
In contrast, the stenting procedure involves inserting a wire mesh device to prop the artery open.
Carotid artery disease is one of the leading causes of stroke and occurs when the arteries leading to the brain become blocked.
The CREST study is the largest clinical trial comparing these two approaches. In all, 2,502 patients were randomly picked to receive either CEA surgery or carotid artery stenting.
The researchers did use embolic protection devices for the stenting procedure, Clark said.
Overall, there was no difference between the two procedures, Clark said, with a 7.2 percent risk of stroke, heart attack and death in the stenting arm of the trial, versus 6.8 percent for surgery. The mean follow-up was 2.5 years.
In the first 30 days after the procedures, there also was little difference in heart attack, stroke or death risk between the two procedures overall: 5.2 percent with stenting and 4.5 percent with surgery.
Death rates were low in both groups, although the rate of all strokes (small, medium, large) was higher in the stented group, 4.1 percent versus 2.3 percent. The rate of large strokes was the same.
Heart attack rates were higher in the surgery group compared with the stenting group (2.3 percent versus 1.1 percent), which, said Clark, was "highly significant."
The overall findings applied to both patients with symptoms and those without symptoms and to men and women, said study lead author Dr. Thomas Brott, professor and director of neurology at the Mayo Clinic in Jacksonville, Fla.
Surprisingly, "there was a slight advantage to surgery for those over 70 which became greater for those as they got older," Brock added. "There was an advantage for those under the age of 70 which got greater as one was younger from that particular point."
In the ICSS trial, which involved over 1,700 patients followed for four months, risks for stroke, heart attack or death were higher in the stented group (8.5 percent) versus those who got the artery-scraping surgery (5.2 percent).
Based on those findings, researchers led by Martin Brown, of The National Hospital for Neurology and Neurosurgery, London, concluded that "completion of long-term follow-up is needed to establish the efficacy of treatment with a carotid artery stent compared with endarterectomy. In the meantime, carotid endarterectomy should remain the treatment of choice for symptomatic patients suitable for surgery."
In the end, approaches to clearing clogged carotid arteries may be decided on a case-by-case basis, Narins said.
"I think patient preference will play a big role but older patients may do better with surgery and younger patients may prefer the less invasive option," he said.
There's more on carotid artery disease at the American Heart Association.