Stent :: Safety of carotid stenting in ‘real-world’ setting

The largest-ever study of carotid stenting in high-surgical risk patients has shown that with proper education and training, community physicians are just as successful at using catheter-based techniques to unclog arteries supplying blood to the brain as are those who pioneered the procedure at major university medical centers.

The study was released online today at www.scai.org, and will be published in the January 2007 issue of Catheterization and Cardiovascular Interventions: Journal of the Society for Cardiovascular Angiography and Interventions.

The CAPTURE study (short for Carotid ACCULINK/ACCUNET Post- Approval Trial to Uncover Unanticipated or Rare Events) involved 3,500 patients at increased surgical risk for carotid endarterectomy and 353 physicians at 144 hospitals across the United States. It addressed several questions critical to the evaluation of any new technology, among them: Could carotid stenting safely make the leap to “real-world,” everyday use, or would the technique prove beneficial only in the hands of expert physicians”

“The ability to transfer the technology to the community was successful,” said Dr. William A. Gray, Director of Endovascular Services and an Associate Professor of Clinical Medicine at Columbia University in New York City. “The study involved multiple physician specialties, multiple experience levels, and multiple sites with very broad geographic representation, and demonstrated that regardless of these differences, outcomes were similar across the board.”

In carotid stenting, a physician threads a catheter through a small puncture in a leg artery and into the narrowed artery in the neck, which feeds blood to the brain. A filter is placed through this catheter and expanded above the blockage to protect the brain during the procedure. A flexible and crush-resistant stent is positioned in the blockage and then expanded with a balloon to hold the artery open. Once the procedure is complete, the filter is collapsed and removed.

The Rx Acculink carotid stent and its companion, the Rx Accunet filter, were approved by the Food and Drug Administration (FDA) in 2004 for the treatment of patients who not only have severe plaque build-up in the arteries in the neck?a condition that hikes the risk of stroke?but other medical problems that make it risky to have the plaque removed surgically. The CAPTURE registry was developed to collect FDA-mandated data to assess the ongoing safety of the Rx Acculink and Rx Accunet devices in a large group of patients, as well as the effectiveness of a training program tailored to the experience level of each physician interested in performing carotid stenting.

The study was well designed, with patients undergoing a neurological examination before the procedure, 24 hours afterward, and at 30 days. In addition, the physicians who examined patients for complications were independent of those who performed the stenting procedure. This latter aspect of the study is one of its major strengths, said Dr. Christopher J. White, editor-in-chief of Catheterization and Cardiovascular Interventions. “Because independent observers measured the outcomes of the procedure, we can have confidence that the data are robust, meaningful, and applicable in community practices,” Dr. White said.

CAPTURE data revealed no unexpected problems with the carotid stenting devices themselves. In addition, patients fared equally well whether treated by highly experienced physicians or those who were new to carotid stenting but had undergone intensive training and on-site mentoring during their first few procedures. The combined rates of death, heart attack, and stroke were 6.3 percent overall?5.3 percent among the most experienced physicians, 6.0 percent among those with a moderate level of experience, and 7.4 percent among those with little previous experience, differences that were not statistically significant.

Carotid stenting experts hope such data will persuade the Centers for Medicare and Medicaid Services (CMS) to expand coverage for carotid stenting. For now, Medicare coverage is available only for patients who are at high risk for surgery and have symptoms before the procedure, but not those who are symptom-free despite severely narrowed carotid arteries. CMS is now re-evaluating that policy in light of data from CAPTURE and other post-market surveillance studies.

“What we?re really working toward is providing patients with greater access to the technology, where we think it is appropriate,” Dr. Gray said.

“The CAPTURE trial is a giant step toward achieving the goal of proving that, in the foreseeable future, nonsurgical carotid stent placement will replace surgery as the treatment of choice for stroke prevention,” said Dr. White.


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