Mar 20 2006
Results from the largest-ever multi-center U.S. registry on the efficacy of carotid stenting shows that the procedure is safe in patients who are at high risk for standard surgical therapy.
The registry, an FDA-required post-approval study, known as CAPTURE (Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Rare Events) was presented at the American College of Cardiology's 55th Annual Session in Atlanta. The multi-center study was led by Columbia University Medical Center researchers at NewYork-Presbyterian Hospital/Columbia.
Patients with carotid artery blockage have an increased risk of stroke, even if they experience none of the disease's symptoms, which can include weakness, paralysis, visual problems or speech difficulties. The risk of stroke over five years in asymptomatic patients is about one in eight if carotid artery disease is treated only with medical therapy. The Center for Medicare and Medicaid Services currently does not cover carotid stenting for these asymptomatic patients, so many turn to surgery to clear blocked arteries. However, some patients are ineligible for surgery because of other medical conditions.
In CAPTURE, the researchers collected data on 2,500 patients at increased risk for surgery. They were treated by 240 interventionalists at 188 medical centers across the country. All patients received Guidant's FDA-approved RX ACCULINK Carotid Stent System with RX ACCUNET Embolic Protection System. Neurologists otherwise unaffiliated with the study also evaluated patients immediately before and after stenting, and again 30 days later to judge the outcomes of the procedure.
Among asymptomatic patients, the trial found that the rate of major complications (death, stroke or heart attack) within 30 days of the stenting procedure was 5.7 percent, which is lower than the rate found in other studies of similar patients who undergo surgery.
"The scope of this landmark trial provides us with a clear picture of the patients who benefit the most from carotid artery stenting. We hope these results will expand coverage to asymptomatic patients who are risky candidates for surgery," said William Gray, M.D., principal investigator on the study and associate professor of clinical medicine at Columbia University Medical Center and director of endovascular services at the Center for Interventional Vascular Therapy at NewYork-Presbyterian Hospital/Columbia and the Cardiovascular Research Foundation.
Preliminary results on 1,600 patients in the CAPTURE trial were presented at the Cardiovascular Research Foundation's Transcatheter Cardiovascular Therapeutics (TCT) meeting in October 2005. The results from the 2500 patients confirm the earlier suggestion that carotid artery stenting is highly beneficial for asymptomatic high-risk patients.
The FDA approved carotid artery stenting for symptomatic patients following the pivotal ARCHeR trial, which enrolled a significantly smaller number of patients at centers with expert experience in carotid artery stenting. The larger CAPTURE trial was designed to determine the safety and efficacy of carotid stenting among a broader group of interventionalists with more variable levels of experience. At 5.7 percent, the CAPTURE trial had an even lower combined rate of death, stroke and heart attack than the ARCHeR trial, which had an 8.3 percent rate. The current study also looked for complications that might have gone undetected in the ARCHeR trial, but did not find any.
The CAPTURE trial found that carotid artery stenting had better outcomes in younger patients. Stroke, death or heart attack occurred in 8.9 percent of patients over the age of 80, compared to 4.8 percent of patients under 80. The lowest percentage of adverse effects - 4.2 percent - were in asymptomatic patients under the age of 80.
It is anticipated that the positive results of this trial will support the re-examination, and eventual expansion, of current CMS reimbursement for this procedure and allow access to this promising technology for a greater number of beneficiaries.
In patients with carotid artery disease, the arteries that supply blood to the brain can develop atherosclerosis, a buildup of fat and cholesterol deposits, decreasing blood flow to the brain and increasing the risk of stroke. Approximately 25 percent of strokes are caused by carotid artery disease. Carotid artery stenting is a minimally invasive procedure that combines balloon angioplasty and a stent implant to unblock and reopen the carotid artery.