In a Reversal, U.S. Says Medicare Wonâ€™t Cover Stents for Neck Arteries
By BARNABY J. FEDER
Responding to criticism from surgeons, the government has dropped its previously announced plans to expand Medicare coverage for the use of stents to prop open neck arteries to prevent strokes.
Instead, Medicare will stick with definitions that restrict eligibility for such stents to fewer than 10 percent of the 150,000 to 200,000 Americans who annually undergo surgery to clear blockages that restrict blood flow to the brain and raise stroke risks.
That is a far more conservative stance on stenting than has been taken by the Food and Drug Administration, which determines when a device is safe and effective enough to be sold commercially. And it is likely to slow the expansion of coverage among private insurers.
The decision, which Medicare regulators published online on Monday night, was an unexpected reversal for stent makers and many doctors who have promoted stenting as a less invasive alternative to neck surgery.
â€œWe were all blown away,â€? said Dr. L. Nicholas Hopkins, a neurosurgeon and radiologist at the State University at Buffalo School of Medicine and Biomedical Sciences who has been involved in many clinical trials of the stents.
Surgery removes plaque where it blocks blood flow in the carotid arteries, the main pathways for blood to reach the brain. In stenting, doctors thread a thin catheter through blood vessels from the thigh to the constricted carotid artery, inflate a balloon inside the blockage to push the plaque aside, and then, using the same catheter, implant the metal stent as a scaffold to keep the artery open.
Carotid plaque accumulation is a symptom of the same disease that clogs arteries in the heart and other parts of the circulatory system. It has been linked to about 25 percent of the 700,000 stroke cases reported annually in the United States.
In 2004, when Guidant became the first company to introduce an F.D.A.-approved product, Wall Street forecast that carotid stenting could eventually become a $1 billion market. That would have made the stents a blockbuster medical device, although the sales pale compared with those of coronary stents, which are implanted to reduce chest pains and, in some patients, to treat heart attacks. But without wider insurance coverage, carotid stenting might not grow much beyond the current level of $100 million or so.
The F.D.A. has approved carotid stents and related gear â€” mostly filters that catch debris loosened during stenting â€” in patients showing no symptoms of blockages if a diagnostic image shows a carotid restriction of 80 percent or more and they have any of a number of conditions that might make an operation risky.
It has also approved marketing the stents to high-surgical-risk patients with symptoms of blockage â€” like a previous stroke or other brain impairment â€” and diagnosed blockages of 50 percent or more.
By contrast, the Centers for Medicare and Medicaid Services, which oversees Medicare, generally will not pay for the device in any patient who has not yet shown symptoms of blockage. Even in symptomatic patients, it requires a diagnosis of at least a 70 percent blockage. Medicare patients who fall outside those standards but within the F.D.A. guidelines can receive coverage only if they are in a clinical trial.
In reversing its plans to align coverage more closely to the F.D.A. marketing guidelines, the Medicare agency noted strong opposition from several medical groups representing specialists who perform the neck surgery, called endarterectomy, and cited various clinical trials that raised doubts about the safety of carotid stenting. It noted but did not accept the charges by leading stenting advocates that such trials had many design flaws and that their results were unreliable.
The Medicare agency â€œis taking a very activist approach in the absence of consensus among the various disciplines,â€? said Dr. Barry T. Katzen, medical director of the Baptist Cardiac and Vascular Institute in Miami. â€œBy making payment in the context of clinical trials, they are trying to advance the science.â€?
Dr. Katzen and others said that Medicareâ€™s conservative stance would help doctors recruit patients for current and future clinical trials.
Abbott Laboratories, which had its first carotid stent approved in 2005 and then acquired Guidantâ€™s last year, had initiated the coverage review with a request for expanded reimbursement last year. It called the agencyâ€™s change of heart disappointing for the patients it had asked Medicare to cover.