The benefits of carotid artery screening for asymptomatic patients don’t outweigh the risks, the U.S. Preventive Services Task Force (USPSTF) has concluded after an extensive review of research findings.
The Task Force found evidence that carotid endarterectomy can reduce the five-year incidence of all strokes or perioperative death by approximately 5% in selected, high-risk patients with asymptomatic severe carotid artery stenosis. However, this benefit would not be as strong among asymptomatic people in the general population, and would be “small” at best in the general primary-care population, the group concluded. Even duplex ultrasonography, the most feasible screening test for severe carotid artery stenosis, yields many false-positive results that can lead to unnecessary endarterectomy.
In addition, both testing for carotid artery stenosis and treatment with endarterectomy present risks. For example, when angiography is part of the testing process, it may cause stroke. Without angiography, the patient may undergo carotid endarterectomy even if the stenosis is not severe. This surgery, too, can lead to stroke.
In a separate action, the USPSTF reaffirmed its 2003 recommendation for screening all adults aged 18 or older for high BP. The group found “good evidence” that detection and the subsequent treatment of hypertension substantially decreases the incidence of cardiovascular events while causing few major harms. “Certainty is high that the net benefit of screening for high blood pressure in adults is substantial,” the USPSTF concludes. The group also recommends that hypertension be diagnosed only after obtaining two or more elevated readings on at least two visits over a period of one week to several weeks.