A national clinical trial conducted by University of Florida investigators and colleagues have discovered that intensive medical therapy might be better by itself in order to prevent a common type of stroke, rather than in conjunction with surgery that props open affected arteries. Although whether this apparent advantage will prove true in the long term, remains to be seen.
The results of this human study will be published online in The New England Journal of Medicine on Wednesday September 7th.
The scientists explained:
“Against expectations, the short-term risk of stroke and related death was twice as high in some cases for patients whose diseased arteries were widened via balloon angioplasty and stent insertion, compared with patients who received medical therapy alone. Although the 30-day risk of stroke for the stenting patients is concerning, long-term results could be more favorable.”
Co-author Michael F. Waters, M.D., Ph.D., director of the Shands at UF Stroke Program, who together with Brian L. Hoh, M.D., the William Merz associate professor of neurological surgery in the College of Medicine, who led the UF portion of the trial, said: “Five years from now, who will be doing better – the patients who are being medically managed, or those who received a stent?”
The researchers also said:
“The study will have a substantial impact on clinical practice and research, because it is the first randomized stroke trial to pit stenting against nonsurgical treatment for symptomatic intracranial atherosclerosis, a type of stroke caused by artery blockage in the brain. Early results clearly show that intensive medical management is key to improving health.”
Walter Koroshetz, M.D., deputy director of the NIH National Institute of Neurological Disorders and Stroke, which funded the clinical trial, stated:
“This study provides an answer to a longstanding question by physicians – what to do to prevent a devastating second stroke in a high-risk population. Although technological advances have brought intracranial stenting into practice, we have now learned that when tested in a large group this particular device did not lead to a better health outcome.”
In the U.S. stroke is the fourth leading cause of death in addition to being a leading cause of disability. In the U.S. someone has a stroke every 40 seconds, and according to the American Heart Association approximately 800,000 individuals per year have a new or recurring stroke. Some parts of the southeastern U.S. are together termed the Stroke Belt, due to higher that average rates of stroke and stroke related deaths.
Existing treatments do not respond well for patients with symptomatic intracranial atherosclerosis (a type of stroke). Of those who suffered this type of stroke, one-fourth with have another within 12 months and the risk of more strokes continues in following years. Doctors are not sure what the best treatment course is.
In order to find this out, the UF investigators and colleagues conducted a clinical trial, nicknamed SAMMPRIS, at 50 locations across the nation, including the lead site at the Medical University of South Carolina. 451 participants were enrolled in the human study, aged between 30 to 80 years of age. They all had at least 70% narrowing in the arteries in the brain, and in the previous 30 days had experienced symptoms. the University Florida enrolled the second-highest number of patients among all sites, through its stroke program, which has been designated a Comprehensive Stroke Center by the Agency for Health Care Administration.
Patients were divided into two groups, in the first group participants were randomly assigned to receive intensive management involving smoking cessation and medications for blood pressure, cholesterol, diabetes and blood-clot prevention. In the other group the participants had the same medical treatment as well as having balloon angioplasty and stent implantation into the affected brain artery in order to improve blood flow.
Within 30 days of being recruited for the investigation, nearly 15% of participants who received stents had a stroke or died, in comparison to just under 6% of participants in the medical therapy group. For almost a whole year, the stark differences between the groups continued, with 21% of participants who received stents experiencing negative effects, compared with 12% in the medical group.
The investigators primarily believed that participants who received stents would have fared better, because of the successful use of similar procedures in clinical practice at the Shands at UF Stroke Program and other medical centers.
However, due to the massive differences between the two groups, the study’s independent safety monitoring body called off new recruitment. Those conducting the trial will continue to monitor those previously enrolled for the next two years.
They explained:
“It’s not unusual for surgical patients to have more complications at first. That’s because the invasiveness of surgery poses an inherent risk regardless of the illness being treated.”
Study co-author and co-principal investigator Hoh, who is an associate professor of radiology and neuroscience in the UF College of Medicine, said:
“The real question is, is there a benefit to patients over the long term. If you think about it, when people are concerned about stroke, it’s not just their first month that matters, so we’re waiting to see what the longer-term results will be.”
With time, improvement of stent design and honing of surgical techniques could help improve outcomes for patients.
Waters said:
“This is certainly not the final say on managing this disease. This is another piece of the puzzle that helps to guide our hand.”
Written by Grace Rattue