麻豆传媒

A vascular surgeon and a primary care doctor disagreed on the value of routine screening for carotid artery stenosis (CAS) in asymptomatic patients, but they agreed in published viewpoints that an older patient with moderate CAS would be not a good candidate for carotid endarterectomy (CEA).

Based primarily on the results of three randomized trials in which patients had at least 50-60% stenosis, the U.S. Preventive Services Task Force in 2014 published a guideline recommending against screening for asymptomatic CAS.

"Screening 100 adults for CAS would identify 4 to 5 patients with at least moderate stenosis, defined as 50% or more, but only one would actually have CAS,"according to Kenneth Mukamal, MD, a primary care physician, participating in a from Boston's Beth Israel Deaconess Medical Center, recorded and published this week in Annals of Internal Medicine.

"Further, confirmatory tests -- typically MR angiography -- rapidly increase the cost of identifying a single case. Medicare reimbursement is approximately $200 for bilateral carotid ultrasound and about $450 for magnetic resonance angiography, requiring nearly $25 000 per case identified, even assuming perfect sensitivity and specificity for magnetic resonance angiography," he continued.

Discussion moderator Gerald W. Smetana, MD, observed that correction of CAS via surgery is associated with potential harms such as death, stroke, cranial nerve injury, pulmonary embolism, pneumonia, MI, and local hematoma.

Yet the detection of CAS doesn't always have to be followed with an expensive intervention, argued discussant Marc Schermerhorn, MD, a vascular surgeon.

"The natural history of CAS is modifiable through risk factor reduction, thus providing a potential rationale for early detection in asymptomatic persons," he said, adding that "screening for carotid stenosis provides an opportunity to reduce risk through optimal medical management, even for patients who opt against CEA or carotid stenting."

In any case, he suggested that improvements in medical management may one day neutralize any perceived benefit of an intervention.

Schermerhorn and Mukamal were presented with the case of "Mr. O": a 74-year-old man with 50% stenosis on carotid ultrasonography and high cholesterol; however, he takes a statin and aspirin for primary prevention and doesn't smoke cigarettes. He had been screened several times at health fairs.

"I do not recommend that any asymptomatic patient undergo routine CAS screening," Mukamal declared. "Time is better spent discussing intensive management of lipids, blood pressure, and blood glucose; a Mediterranean or DASH diet; tobacco cessation; and regular physical activity."

And even with the moderate stenosis detected in this case, there is no need for carotid endarterectomy or stenting at this time, said Schermerhorn. Instead, he recommended that the patient optimize lipid management and enter the if stenosis ever crosses the 70% threshold.

Mukamal also advocated the trial for Mr. O if he is willing. "If not, or for patients who cannot enroll or who are not eligible, I recommend repeating his ultrasound at a high-volume center that performs internal validation and overreading, followed by referral if confirmed."

Two ongoing parallel trials make up : one randomizing patients with known CAS to endarterectomy versus intensive medical management; and the other randomizing participants to carotid stenting versus intensive medical management.

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