Stroke study puts 2 procedures on equal footing
For patients with a hardening of the neck arteries that can lead to a stroke, balloon angioplasty and stenting are virtually as effective and safe as the long-used gold standard of surgical removal of the plaque, according to the largest comparison of the two procedures ever conducted.
Results from the CREST trial on more than 2,500 patients in the United States and Canada, reported Friday at the International Stroke Conference in San Antonio, suggest that either procedure is a good way to limit the risks of having a stroke and that the choice between the two could be more a matter of patient preference than scientific certainty.
Stroke was “a bit more common” in patients who underwent stenting, and heart attacks were a bit more common in those who had surgery, said lead investigator Dr. Thomas G. Brott of the Mayo Clinic in Jacksonville, Fla. “Unfortunately, there is not a lot of scientifically valid information that tells us which is more important to the patient.”
Overall, “this was the lowest rate of adverse events ever reported in a stroke trial,” said Dr. Steven Schiff, medical director of Invasive Cardiovascular Services at Orange Coast Memorial Medical Center in Fountain Valley, who was not involved in the study. “That’s very powerful.”
The results come out the same day that European researchers are reporting findings from their comparison of the two procedures in the journal Lancet. That study, called ICSS(10)60239-5/fulltext, compared only strokes and deaths, but the complication rates for both procedures were higher than in the U.S. trial.
“It doesn’t surprise me that we got better results with stenting in the U.S., where we have had much broader experience,” said Dr. Gary Roubin of Lenox Hill Hospital in New York, one of the co-authors of the CREST study. “North American surgeons do the job better.”
Added Dr. Nerses Sanossian, a stroke neurologist at USC’s Keck School of Medicine, who was not involved in either study: “CREST is a landmark study because it shows that the two approaches are equivalent. Before CREST, stenting had no role whatsoever in managing routine . . . stenosis patients. Now we have to reevaluate it.”
Strokes are the No. 3 cause of death in the United States and the leading cause of adult disability, affecting about 800,000 people each year. At least 10% of strokes are caused by atherosclerosis, or stenosis, in the carotid artery that feeds the brain -- occurring when plaque breaks off and causes a blockage in the organ’s smaller blood vessels.
Patients who have had symptoms from the stenosis, primarily minor strokes called transient ischemic attacks, have a 25% risk of having a more severe stroke in the following year. Patients who have a 70% or greater blockage of the artery but no symptoms have a 2% per year risk of severe strokes. In the absence of symptoms, carotid blockage can be determined by listening for abnormal sounds in the artery and by ultrasound.
Surgery to remove plaque, called an endarterectomy, has been around since the 1960s and is the second most common type of surgery in the United States, with about 150,000 people undergoing it each year. Carotid angioplasty and stenting, in which a mesh-like spring is inserted to prop the artery open, was introduced about 15 years ago and is now performed on about 20,000 people a year. As with coronary angioplasty, a balloon is first inflated inside the artery to crush the plaque.
Medicare and most insurance companies do not cover carotid stenting unless the patient has symptoms and is at elevated risk from a surgical procedure because of obesity, heart disease or other factors.
Intervention, surgical or otherwise, is clearly called for in those with symptoms, according to Dr. Walter Koroshetz, deputy director of the National Institute of Neurological Disorders and Stroke, which funded CREST. About seven patients must be treated to prevent one bad stroke, he said.
But treating asymptomatic patients has been more controversial because their absolute risk is so much lower. CREST is the first study to include asymptomatic patients, and it showed that they can also be safely treated, Koroshetz said.
CREST physicians enrolled 2,502 patients who were treated at 117 centers. Surgeons who performed endarterectomies and those who did angioplasties had to show proficiency in the techniques before they entered the trial, an approach that was not used in the European study.
Overall, 4.1% of those in the stenting group had strokes in the weeks following the procedure, compared with 2.3% of those who had surgeries. But 2.3% of those in the surgical group had heart attacks, compared with 1.1% of those in the stenting group.
Patients over the age of 70 did better with stents, and those who were younger did better with surgery.
The ICSS study enrolled 1,713 patients at centers throughout Europe. The team reported in Lancet that 8.5% of stented patients suffered a heart attack during the procedure or had a stroke or died with 120 days, compared with 5.2% of those undergoing surgery.
Among the differences between the two studies, beyond surgical proficiency: All the North American surgeons used a stent produced by Abbott Laboratories, and the European groups used different stents; all of the American groups used a filtering device to catch any small clumps of plaque that might be released during the angioplasty, and only three-quarters of the European groups did so; and physicians in the European trial who assessed the patients after the procedures knew which procedure they had received.
“Neither of the studies shows a home run for either procedure,” said Dr. Karl Illig, a cardiologist at the University of Rochester Medical Center. “I betcha . . . that people who are at low risk for surgery will continue to undergo surgery and people at high risk will undergo stenting.”
