Originally Published MDDI June 2005

NEWSTRENDS

Erik Swain

Procedures such as carotid artery stenting could become more common in the near future. One reason is the emergence of genomic-based medicine, which will give clinicians a better idea of who is at high risk for what. And, a new national coverage policy from the Centers for Medicare and Medicaid Services (CMS; Baltimore) is also playing a role.

In April, CMS issued a draft guidance outlining the policy of “coverage with evidence development.” Significantly, one way a procedure could be covered under this system is “when a particular medical intervention has yet to conclusively demonstrate an improvement in health outcomes, but existing information clearly suggests the intervention may provide an important benefit.”

Abbott Vascular Devices (Redwood City, CA) has begun enrolling patients in a clinical trial to see whether asymptomatic patients at high risk for stroke would benefit from carotid artery stenting. Many such people are not treated at all. Some undergo a surgical procedure called carotid endarectomy. The trial will compare patients who had stents with patients who had the surgery.

In March, CMS said it would cover carotid artery stenting for patients who are at very high risk for stroke but who could not withstand surgery. But CMS wants to see more data before expanding the coverage more broadly. That is one of the goals of Abbott's trial. “We met with CMS. They want peer-reviewed, published data, and we intend to provide that,” says Don Schwarten, MD, Abbott Vascular's vice president for endovascular affairs and chief medical officer.

“After five years, [asymptomatic] patients who had surgery had half the risk of stroke of those who had [nonsurgical] therapy; usually statins,” says Schwarten. “Therefore, we felt that this statistic was additional evidence that some sort of revascularization could benefit [asymptomatic] patients if they had significant stenosis—70% or greater. The degree of stenosis corresponds to future risk of stroke.”

Schwarten says the company made the decision to conduct the trial in 2002, and neither of the CMS pronouncements were a factor. But, he says, the climate is such that Abbott is comfortable doing trials for preventive procedures if the cost-benefit factors are favorable.

“For example, take lower-extremity occlusion. Only a small percentage of patients advance to the worst-case scenario, which is to lose a leg. Most will be exactly the same five years after they are diagnosed,” he says. “There is little incentive to put those [asymptomatic] patients at risk.” By contrast, he notes, asymptomatic patients with carotid artery stenosis are at high risk of having a stroke that causes debilitation or death. So in these cases, device-related intervention could be justified.

The stenting portion of the trial features Abbott's Xact carotid stent and its Emboshield embolic protection system. Both are approved in the European Union, and Abbott expects FDA approval by the end of 2005. The trial is not part of the FDA application process.

Reimbursement expert Ted Mannen, managing director of ContentHealth (Washington, DC), says there is some precedent for the Abbott procedure, chiefly implanting defibrillators in asymptomatic-but-high-risk patients with heart problems. But, he says, it is still uncommon. Yet, “as we learn more about genomics, we will have greater ability to do these kinds of things.”

Will CMS adapt along with industry? “My sense is that CMS will support it if the evidence is there,” Mannen says. “The new guidance shows that they are seeking to make evidence-gathering a bigger part of a national coverage decision.” Mannen notes that there must be a lot of companies thinking about this. “The question is how many, like Abbott, are willing to do a trial?”

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