LOS ANGELES (Feb. 13, 2008) - A preliminary study funded by the National Institutes of Health found that a stent designed to open clogged arteries in the brain was successfully deployed in nearly all cases and significantly reduced arterial blockage in the short term. But data on the long-term benefit of the stent, compared to medical treatment alone, were inconclusive, prompting the upcoming launch of a large-scale randomized trial that is expected to provide definitive results.
The NIH Wingspan Registry collected statistics on 129 patients who had an intracranial artery narrowed by at least 70 percent and were experiencing recurrent strokes or transient ischemic attacks (TIAs or "mini-strokes") despite being on anti-clotting medication. Treatment included use of the Wingspan intracranial stent developed by Boston Scientific. Seven centers in the United States participated in the trial, and results are published online in the journal Neurology.
"Treatment options for stroke patients with severe blockages are extremely limited. As opposed to the situation in blocked heart arteries where options include angioplasty, stenting and surgical bypass, there is no surgical option for these blockages in the brain. This stent may be a major advance for patients with high-grade stenosis (arterial narrowing) who have a stroke or TIA. Previously they could just take medication and expect to have a high recurrent stroke rate," said neurosurgeon Michael J. Alexander, M.D., one of the article's authors and director of the Cedars-Sinai Neurovascular Center. Before coming to Cedars-Sinai Medical Center in 2007, Alexander was founder and director of the Neurovascular Center at Duke University, where he was one of the Wingspan study leaders.
The Wingspan trial followed another NIH-funded study comparing two blood-thinning medications commonly used to treat narrowing of intracranial arteries. The Warfarin-Aspirin Symptomatic Intracranial Disease Study (WASID) found that warfarin (commonly known by the brand name Coumadin) and aspirin provided similar stroke protection, but aspirin was associated with a lower risk of hemorrhage and related complications.
The WASID study also found that a patient who recently had a stroke or TIA and suffered a cranial artery blockage of 70 percent or higher had a 22 percent chance of having another stroke within the first year, regardless of which medication was used. While the objective of the WASID trial was to compare the two drugs, results of the medication study provide a baseline against which other therapies can be compared.
"We know that patients with 70 percent to 99 percent stenosis and TIA or stroke within the previous 30 days are at highest risk of having another stroke," Alexander said. "These are the patients who have the most to gain from stenting and are the ones we will target for enrollment in the randomized trial of stenting versus medical therapy."
Alexander is one of about a dozen specialists in the country trained in both neurovascular surgery and neurointerventional radiology. A member of the steering committee for the upcoming prospective randomized trial - Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) - he expects Cedars-Sinai to be one of several large centers in the state participating.
Citation: Neurology, "The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis," published online January 30, 2008.
Disclosure statement: Dr. Alexander was involved in the Wingspan NIH Registry and is on the steering committee for the prospective randomized NIH-funded trial referenced in this news release (SAMMPRIS). He is a paid device proctor and research consultant for Boston Scientific.