Carotid Stent Market: Stalled on Several Fronts

When FDA approved the first carotid stent, in August 2004, many industry analysts suggested that the market for such devices could reach $1 billion by 2010. Since that time, however, forecasts have been adjusted downward as U.S. carotid stent manufacturers continue to face a number of hurdles on the approval, reimbursement, and professional practice fronts.

Carotid stents are used to prevent strokes by unclogging arteries in the neck that can become partially blocked with a buildup of fatty plaque and debris. Known as atherosclerosis, the condition results in an estimated 700,000 strokes and 280,000 deaths in the United States annually. The stenting procedure uses balloon angioplasty and employs a device that typically includes two components: the carotid stent and a mesh filter system designed to capture any emboli or debris material that might become dislodged during the procedure.

Among the medtech manufacturers involved in developing carotid stents, leading the pack hasn't proven to be a sign of imminent market success. As early as 2002, Boston Scientific reported the first human use of a carotid stent in U.S. clinical trials. While the company's Wallstent carotid stent is the market leader outside the United States, it has never been submitted to FDA for approval.

Cordis Corp. (Miami Lakes, FL), a Johnson & Johnson company, was the first medtech firm to seek FDA approval of a carotid stent, but the company is still awaiting final word from the agency. The company's Precise carotid stent received a positive recommendation from FDA's circulatory systems advisory panel and was subsequently deemed “approvable” by the agency. The holdup in final approval is believed to be related to some lingering issues connected to Cordis's noncompliance with FDA good manufacturing practices for its Cypher drug-eluting coronary stent.

To date, FDA has approved only two carotid stents: the Aculink from Guidant Corp., now a unit of Boston Scientific Corp. (Natick, MA), and the Xact carotid stent from Abbott Laboratories Inc. (Abbott Park, IL). Meanwhile, Medtronic Corp. (Minneapolis) received European Union approval for its Exponent carotid stent in April 2006, and is anticipating U.S. market entry sometime in 2007.

The Centers for Medicare and Medicaid Services (CMS; Baltimore) last reviewed carotid stenting in March 2005. But the expanded Medicare coverage offered by the agency at that time fell far short of what many interventional cardiologists and industry analysts had expected. CMS currently covers the procedure only for patients having symptoms of atherosclerosis and arterial blockages between 50 and 70%, or asymptomatic patients with arterial blockages of 80% or more. Symptoms of atherosclerosis include weakness, paralysis, visual problems, and speech difficulties. All such patients must also be considered at high risk for the traditional surgical procedure, called endartarectomy. About 150,000 carotid surgeries were performed in 2004.

CMS also limits reimbursement to procedures performed by specially trained physicians in facilities designed to support a dedicated carotid stenting program, including the necessary imaging equipment, device inventory, staffing, and infrastructure resources.

Several clinical studies have documented the safety and efficacy of carotid stenting, including a report presented this March at the annual meeting of the American College of Cardiology (Bethesda, MD). That study looked at patients who had undergone carotid stenting with Guidant's AccuLink device, and included 2500 patients in 188 medical centers across the United States.

The U.S. carotid stenting market is currently valued at around $60 million, leaving a long road ahead to achieve early projections of $1 billion by 2010. But Mark Landy, president of MIV Therapeutics Inc. (Vancouver, BC, Canada), a developer of biocompatible coatings for cardiovascular stents and other implantable medical devices , believes that the market will eventually catch up with earlier forecasts. “Although carotid stenting has been around for a number of years, it's still considered a pioneering technology when compared to traditional endartarectomy, and it's going to take time to gain acceptance,” says Landy. “If you look at coronary stents, implantable cardioverter defibrillators (ICDs), insulin pumps, and numerous other devices, they, too, often failed to meet the early projections of Wall Street.”

Prior to assuming his new corporate role with MIV Therapeutics this past April, Landy was a highly regarded medtech industry analyst for many years. According to Landy, “Most initial predictions and market assessments of innovative medical devices were wrong.”

There remains a great deal of resistance to carotid stenting from vascular surgeons, who cite the established history and success rate of traditional endartarectomy. Nevertheless, Landy believes, more-robust clinical data and comparative studies will in time provide a significant stimulus for clinical acceptance—and market growth—over the next several years.

© 2006 Canon Communications LLC

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