Medication more effective than stenting in stroke patients, study finds
People at high risk of suffering a second stroke appear to fare better on a meticulous regimen of medications rather than having surgery to insert an artery-opening stent in the brain, according to a new report.
The results of the study on how to best treat a narrowing of brain arteries, called stenosis, surprised researchers who had expected stenting to be the superior treatment, and the much higher incidence of second strokes and deaths in patients who received stents led to the early termination of the study in April.
The results, published online Wednesday by the New England Journal of Medicine, should lead to immediate changes in medical practice, experts said. Stenting to prevent a second stroke, formally known as percutaneous transluminal angioplasty and stenting, has become popular in the last few years, although it’s not covered by Medicare.
“The most intuitive thing is to fix the blood vessel and get rid of the narrowing. That is what the trial was intended to show,” said Dr. Walter Koroshetz, deputy director of the National Institute of Neurological Disorders and Stroke, who oversaw the study. “It doesn’t always turn out that that is the best thing for the patient. And that is what happened here.”
Clogging of the arteries that feed blood into the brain is among the most common causes of ischemic stroke and one that is expected to rise as the population ages and becomes more obese. The condition is more common in African Americans and Latinos.
Doctors have struggled with how to prevent a second stroke when tests show blockage of more than 70% in a major intracranial artery. Almost 25% of people with such a blockage will have a second stroke within one year despite treatment with aspirin and other medications.
Stents are routinely used to open the carotid artery and clogged vessels in the heart. However, stenting in the brain is trickier because of the circuitous route of intracranial blood vessels.
The federally funded study enrolled 451 people from 50 medical centers around the country who had suffered a recent ischemic stroke and had narrowing of an intracranial artery of 70% or more. All of the participants were closely managed with medications including aspirin and the blood-thinning medication clopidogrel (Plavix) and treated aggressively for other risk factors that can cause stroke, including high blood pressure, high cholesterol levels and poorly controlled diabetes. The participants were also instructed to exercise and quit smoking.
Of the 451 patients, 224 also received stents.
Investigators had expected that stenting would decrease the risk of a stroke or death by 35% over two years compared with medical therapy alone. Instead, nearly 15% of the patients in the stenting group had a stroke or died within the first 30 days of joining the study, compared with about 6% in the medication-only group. After about one year of follow-up, almost 21% of the patients in the stenting group had a stroke or died, compared with almost 12% in the medication group.
Based on that data, experts monitoring the trial for safety recommended halting new enrollment.
“The data are pretty convincing that stenting of this population with this device is not safe,” said the lead author of the study, Dr. Marc Chimowitz, a neurologist at the Medical University of South Carolina in Charleston. “That is the reason the study was stopped. We’ve made some inroads to treating these patients, but that happens to be with medical management, not with stenting.”
It’s not clear why stenting led to inferior results, Chimowitz said. It could be that stenting disrupts unstable plaque, triggering a second stroke, he said.
Previous studies on the stenting device used in Chimowitz’s study, the Gateway-Wingspan stenting system made by Stryker Corp. of Kalamazoo, Mich., showed lower rates of stroke and death. Other stents are used off-label for intracranial blockage but were not evaluated in this study.
“I think people will still hold on to the idea that if there was a safe way to get rid of the narrowing, people will do better over time,” Koroshetz said. “Better technology may be the answer.”
Of equal importance, however, is the question of why medication worked so well. Doctors uniformly praised the results obtained by aggressive medical management and lifestyle changes but said such close supervision of patients is unusual.
“If I were going to tell my patients one thing from this study, it would be if you really do work on your risk factors, you can dramatically lower your chance of stroke,” said Dr. Patrick D. Lyden, chairman of the department of neurology at Cedars-Sinai Medical Center, which was one of the study sites.
Lyden defended the practice of stenting in selected patients and in medical centers with expertise in intracranial stenting. The success of the procedure is highly dependent on physician skill, he and other experts noted.
“My take from the study is that stenting in intracranial arteries is much more difficult than we thought it was, and you really need experienced neurosurgeons” and interventional neuroradiologists, he said.
