Correction: An earlier version of this story reported incorrect rates for the secondary end point of any stroke and any major hemorrhage for patients treated with percutaneuous transluminal angioplasty compared with medical management. This version has been corrected.
Aggressive medical management was superior to intracranial stenting for preventing recurrent stroke in patients with intracranial artery stenosis in the first randomized clinical trial to compare the two approaches.
The main drawback with percutaneous transluminal angioplasty and stenting (PTAS) was the relatively high rate of the combined primary end point of stroke or death within 30 days of enrollment or after revascularization of the target artery at any time during follow-up, or an ischemic stroke in the territory of the target artery at any time during follow-up. The trial was halted early when an interim analysis revealed that in the PTAS group, this rate was more than double what was observed in the medical therapy group (14.7% vs. 5.8%), Dr. Marc I. Chimowitz of the stroke program at the Medical University of South Carolina, Charleston, and his associates reported online Sept. 7 in the New England Journal of Medicine.
This trial, called the SAMMPRIS (Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis) study, involved the self-expanding Wingspan stent system (marketed by Stryker Neurovascular, formerly Boston Scientific Neurovascular), the only device approved by the Food and Drug Administration for use in treating atherosclerotic intracranial arterial stenosis. However, other similar devices are widely used "off label" in clinical practice. "Over the past decade, intracranial PTAS has increasingly been used in the United States and other countries," the investigators noted.
"The SAMMPRIS study results have immediate implications for clinical practice. Stroke patients with recent symptoms and intracranial arterial blockage of 70% or greater should be treated with aggressive medical therapy alone that follows the regimen used in this trial as closely as possible," Dr. Chimowitz said in a statement from the National Institute of Neurological Disorders and Stroke, which funded the trial.
The study enrolled 451 patients at 50 medical centers who had had a transient ischemic attack or a nondisabling stroke within the preceding 30 days, which was found on angiography to be due to 70%-99% stenosis of the diameter of a major intracranial artery. In all, 227 subjects were randomly assigned to receive aggressive medical management alone and 224 to receive identical medical therapy plus PTAS (N. Engl. J. Med. 2011 Sept. 7 [doi:10.1056/NEJMoa1105335]).
The medical management comprised daily aspirin (325 mg), daily clopidogrel (75 mg) for 90 days after enrollment, management of primary risk factors such as hypertension and hypercholesterolemia, and management of secondary risk factors such as diabetes, smoking, excess body weight, and insufficient exercise using a lifestyle modification program.
The probability of the combined primary end point at the end of 1 year of follow-up also differed significantly between the two groups (20% with PTAS and 12% with medical management).
There were five stroke-related deaths in the PTAS group (2.2%), compared with one death unrelated to stroke in the medical management group (0.4%).
Among the 33 strokes that occurred in the PTAS group within 1 month of enrollment, 25 happened within a day of the procedure and the remaining 8 took place within a week.
PTAS also led to a significantly higher rate of the secondary end point of any stroke and any major hemorrhage (23.2%), compared with medical management (16.3%).
"Contrary to what we hypothesized, the results of this trial showed that aggressive medical therapy was superior to PTAS with the use of the Wingspan system in high-risk patients with intracranial stenosis, because the rate of periprocedural stroke after PTAS was higher than expected and the rate of stroke in the medical management group was lower than estimated," Dr. Chimowitz and his colleagues wrote.
With regard to the success of medical therapy, "we were surprised at the extent and rapidity of the reduction" in recurrent stroke, they noted.
"One possible explanation for the higher rate of periprocedural stroke in this trial as compared with the [device] registries is that all the patients in this study had stenosis of 70% to 99% and recent symptoms, whereas the registries included patients with stenosis of 50% to 90% and symptoms that had occurred more than 30 days before enrollment. Recent symptoms may be a marker for unstable plaque, which could increase the risk of distal embolism during stenting," the researchers wrote.
The study findings warrant an immediate change in clinical practice. "Although not all the components of the aggressive medical regimen used in this trial may be easy to duplicate in clinical practice, essential elements can readily be adopted, including adding clopidogrel to aspirin for the first 90 days and following the trial’s protocol with respect to lowering blood pressure and LDL cholesterol," they wrote.