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Physicians interested in expanding Medicare coverage for carotid stenting were taken by surprise when the Centers for Medicare and Medicaid Services issued a decision to maintain its current policies just 1 day before new data supporting the procedure were published.

Medicare's current national policy covers patients considered at high risk for surgery with symptomatic carotid artery blockage of 70% or greater. Other patients that fit within the Food and Drug Administration-approved population--which includes symptomatic patients with stenosis levels as low as 50% and asymptomatic patients with 80% or greater blockage--are covered only in the confines of an investigational device exemption clinical trial.

The agency issued its final decision memo declining to extend coverage for carotid artery angioplasty and stenting to additional patients on Oct. 14 (www.cms.hhs.gov/mcd/viewdecisionmemo.asp?id=216). Under statutory requirements, the decision was not due until Oct. 29.

The next day, registry data from 2,000 patients were published on the Web site of the journal Catheterization and Cardiovascular Intervention. The SAPPHIRE Worldwide registry, supported by Johnson \& Johnson/Cordis as an FDA post-market approval requirement for its Precise carotid stent system, measured the 30-day major adverse event rates in patients at high risk for open-neck surgery. According to the researchers, the 4.4% event rate identified in the study is comparable with outcomes in typically lower-risk patients who get carotid endarterectomy surgery, and supports stenting in patients who are being targeted for coverage because they have certain risk factors for surgery.

An attempt by Abbott/Guidant to get general coverage extended to more FDA-approved patients was rejected by the CMS last year. But in February, the agency reopened a coverage determination process at the request of the Society for Cardiovascular Angiography and Interventions (SCAI), the American College of Cardiology, the Society of Vascular and Interventional Neurology, and the Society for Vascular Medicine.

The societies focused the CMS' attention on a subset of patients within the FDA-approved carotid artery stenosis ranges that is at high risk for surgery because of certain anatomic factors, rather than other comorbidities that also might qualify a patient as high risk in the symptomatic, 70%-or-greater population. The groups identified 10 specific anatomic factors, including a surgically inaccessible lesion located "above cervical vertebra C2," an immobile neck, and severe tandem lesions, that they said were particularly troublesome for performing open surgery and were associated with good stenting results.

Yet the CMS was unconvinced. In its decision memo, the agency characterized published data comparing stenting with carotid endarterectomy surgery as being of "limited quality." None of the evidence has the statistical power to support conclusions about the benefits of stenting and the dangers of surgery in the specific anatomic risk groups targeted, the CMS wrote. The agency also remains concerned that there is not clear clinical consensus between interventionalists and surgeons on treatment guidelines for carotid artery disease. "We found limited literature comparing outcomes of [surgery or stenting] in patients with the anatomic risk factors on the requestor's list and were unable to find a list generally accepted by all specialty societies," the CMS stated.

Surgeons who perform carotid endarterectomies, represented by the Society for Vascular Surgery, are not opposed to expansion of carotid stenting in all cases, but they are more conservative about which patients should get stents and skeptical that some of the risk factors identified by SCAI do actually contraindicate a patient from surgery.

The SVS, represented by society president, Dr. K. Wayne Johnston, submitted a letter March 2008 calling for restraint (www.cms.hhs.gov/mcd/publiccomment_popup.asp?comment_id=18434). The SVS recommended expansion of Medicare coverage for carotid artery stenting (CAS)with embolic protection to include patients with transient ischemic attack or minor stroke who are found to have a 50%-69% ipsilateral carotid stenosis, and who also have one of the six anatomic markers that establish high surgical risk for carotid endarterectomy (CEA). The specific anatomic markers comprise and should be limited to:

• Previous CEA with recurrent stenosis.
• Prior ipsilateral radiation therapy to neck with permanent skin changes.
• Previous ablative neck surgery (e.g., radical neck dissection, laryngectomy).
• Common carotid artery stenosis below the clavicle.
• Contralateral vocal cord paralysis.
• Presence of a tracheostomy stoma.

The SVS also recommended expansion of Medicare coverage for CAS with embolic protection to include asymptomatic patients who are found to have an 80%-99% carotid stenosis, and who also have one of six anatomic markers, noted above, that establish high surgical risk for CEA. The specific anatomic markers should be limited to those listed above.

In addition, the letter from the SVS called for rescinding the previous decisions regarding octogenarians. "In the CREST lead-in data, stroke/death rates for octogenarians undergoing CAS was 12.1%. In CAPTURE, the stroke rate alone was 7.2% for patients 80 years or older. The finding of marked increase in very procedural stroke risk for octogenarians is ubiquitous. SVS recommends that CMS rescind coverage for CAS in any and all subgroups of octogenarians until further research allows for identification of safe elderly subsets. CMS should encourage research within the very elderly to help determine which of these patients can be stented safely," Dr. Johnston wrote.

The current CMS decision acknowledges that unpublished data suggest a trend toward sufficient outcomes from carotid stenting in the anatomic high-risk groups. The CMS does not give much weight to results not appearing in peer-reviewed journals, but it says it is prepared to react when the publication threshold is met.

We "strongly urge ... publication at the soonest possible time," the memo states. "We will work with any requestor as soon as [those data are] published to determine the need for an expedited review and reconsideration."

The SAPPHIRE registry, as well as Abbott's CAPTURE 2 and EXACT registries, include patients at high risk for surgery because of a range of factors not limited to the anatomic issues targeted for coverage. But Bonnie Weiner, the immediate past president of the SCAI, said in an interview that a significant component of the registry patients do have anatomic-based risk; the data "absolutely" provide the statistical power that the CMS is asking for, she said.

In SAPPHIRE, 716 patients out of 2,001 had anatomic rather than physiologic risk factors, and an additional 327 had both risk types. The anatomic group had a lower adverse event rate than did the physiologic group (2.8% vs. 4.9%). Despite the data, Ms. Weiner said she is not sure if and when a new national coverage request will be pursued.

"We are going to need to regroup at this point and decide what the best approach is," she said.

Also, a clinical guidelines document being drafted by various societies on carotid artery disease treatments could be helpful if it demonstrates a clearer consensus within the medical community. But the earliest that document will be available is in the spring, and it is unpredictable what positions the guidelines will take