Blog | Wednesday, February 19, 2014

QD: News Every Day--Don't screen for asymptomatic carotid artery stenosis, Task Force draft guidance recommends


The U.S. Preventive Services Task Force recommends against screening for asymptomatic carotid artery stenosis (CAS) in the general adult population, according to a draft guidance posted to the agency’s website. This is a D recommendation (moderate or high certainty that the service has no net benefit or that the harms outweigh the benefits.)

Although CAS (defined as 60% to 99% stenosis) is a risk factor for stroke, only a relatively small proportion of strokes result from it. The most feasible screening test for CAS is ultrasonography, which yields many false-positive results in the general population, where CAS is present in approximately 0.5% to 1%.

The Task Force wrote that carotid endarterectomy (CEA) by selected surgeons reduces the absolute incidence of all strokes or perioperative death by approximately 3.5% compared with medical management, the magnitude of these benefits would be less among asymptomatic persons in the general population. “For the general primary care population, the magnitude of benefit is small to none,” the draft guidance reads.

“Although screening with ultrasonography has few direct harms, all screening strategies, including those with or without confirmatory tests (i.e., digital subtraction or magnetic resonance angiography), have imperfect sensitivity and specificity and could lead to unnecessary interventions and result in serious harms. In selected centers similar to those in the trials, CEA is associated with a 30-day stroke or mortality rate of about 2.4%; reported rates range up to about 5% for low-volume centers and up to 6% in certain states. Myocardial infarctions are reported in 0.8% to 2.2% of patients after CEA. The 30-day stroke or mortality rate after carotid angioplasty and stenting (CAAS) is approximately 3.1% to 3.8%.”