Who is the target population?

In European men aged 60–79 years, moderate to severe carotid atherosclerosis (50–99% using North American Symptomatic Carotid Endarterectomy Trial (NASCET) measurements) is found in 2.3–6.0%,1 a similar prevalence to aortic aneurysmal disease (4.9%)2 for which a UK National Screening Programme has recently been introduced for men aged 65.

In high-risk populations seen in a vascular clinic, the prevalence of asymptomatic 50–99% carotid atherosclerosis is much higher: 15–25% in peripheral arterial disease,3 12% in patients with an abdominal aortic aneurysm4 and 6% in those with contralateral carotid territory cerebral or retinal ischemic events.5 Opinion is divided as to whether these individuals should be tested for asymptomatic carotid atherosclerosis. The American Society for Neuroimaging6 and the US Society for Vascular Surgery7 strongly recommend testing in high prevalence populations such as those with symptomatic peripheral arterial disease and persons aged 65 or over with multiple cardiovascular risk factors (table 1). Conversely, the UK Royal College of Physicians draft 4th National Clinical Guideline for Stroke8 does not recommend testing at all. For cardiac patients in the UK, further observational data are awaited regarding prevalence and outcomes of synchronous carotid and coronary revascularization before evidence-based recommendations can be made.9