Task Force confirms recommendation against screening for asymptomatic carotid artery stenosis

The U.S. Preventive Services Task Force reconfirmed its recommendation against screening for carotid artery stenosis in the general adult population in adults without a history of transient ischemic attack, stroke, or other neurologic signs or symptoms. The decision is a D recommendation, meaning there is strong or moderate evidence that there is no benefit, or that the harms outweigh the benefits.

The recommendation statement and evidence review were published in the July 8 Annals of Internal Medicine.

Researchers conducted a systematic review of 56 published studies and found no evidence of a benefit for screening for carotid artery stenosis in the general population but did find a small to moderate risk for harms, such as stroke, myocardial infarction, and mortality, resulting from the interventions that may follow positive screening results.

The most feasible screening test for carotid artery stenosis (defined as 60% to 99% stenosis) is ultrasonography, the report stated. Although the test has high sensitivity and specificity, in practice ultrasonography yields many false-positive results in the general population, which has a prevalence of carotid artery stenosis of between 0.5% to 1%. The Task Force authors wrote that there are no externally validated, reliable tools that can determine who is at higher risk for carotid artery stenosis, or at higher risk for stroke when carotid artery stenosis is present.

In selected trial participants with asymptomatic carotid artery stenosis, carotid endarterectomy (CEA) performed by selected surgeons reduced the absolute incidence of all strokes or perioperative death by approximately 3.5% compared with medical management. However, these studies are now decades old, so the difference is probably smaller with current optimal medical management. The recommendation also noted that the magnitude of these benefits would be less in asymptomatic people in the general population. For the general primary care population, the magnitude of benefit is small to none. “There is no evidence that identification of asymptomatic carotid artery stenosis leads to any benefit from adding or increasing medication doses beyond current standard medical therapy for cardiovascular disease prevention,” the authors wrote.

An accompanying editorial noted that although the data clearly support the Task Force's recommendation against population screening, these types of screenings are still offered to the public at health fairs and other settings. He noted that the American Academy of Neurology, as part of the ABIM Foundation's Choosing Wisely campaign, states that physicians should not recommend endarterectomy for asymptomatic carotid stenosis unless the complication rate is low (<3%). “Although this may need to be revised in the future,” the editorialist wrote, “an appropriate additional recommendation could be, ‘Don't perform population screening for asymptomatic carotid artery stenosis.’”