Ultrasound Surveillance for Carotid Stenosis
Surveillance Recommendations
- The American College of Cardiology recommends annual ultrasound surveillance for mild carotid stenosis (<50%) 1, 2
- For patients with mild carotid stenosis (<50%), surveillance is generally not indicated during the first year after diagnosis 3
- The American Heart Association suggests that once stability has been established over an extended period, longer intervals between scans or termination of surveillance may be appropriate for patients with mild carotid stenosis (<50%) 4, 1, 5
- For moderate stenosis (50-69%), annual ultrasound studies are rated as appropriate 3
- For severe stenosis (≥70%), ultrasound studies at 6 months and then every 6 or 12 months are considered appropriate 3
- The American College of Cardiology recommends consideration of revascularization (carotid endarterectomy or stenting) for patients with severe stenosis (≥70%) 3
Factors Affecting Surveillance
- The American College of Cardiology suggests that once stability has been established over an extended period, longer intervals between scans may be appropriate 4, 1, 6
- If the patient's candidacy for intervention has changed, modification of surveillance intervals or termination of surveillance may be considered 1, 5
Important Considerations
- The American Heart Association recommends that all surveillance ultrasounds should be performed by a qualified technologist in a certified laboratory 4, 1, 6
- Routine serial imaging is not recommended for patients who have no risk factors for development of atherosclerotic carotid disease and no disease evident on initial vascular testing 4, 1, 6
- The American Heart Association suggests that medical therapy should be optimized for all patients with carotid stenosis, including antiplatelet therapy, statins, and management of cardiovascular risk factors 2
Management of Asymptomatic Patient with Carotid Bruit and <50% Stenosis
Assessment and Follow-up
- No further testing is needed for an asymptomatic patient with a carotid bruit and less than 50% stenosis bilaterally on carotid ultrasound duplex, as recommended by the American College of Cardiology and based on guidelines from neurointerventional surgery 7, 8
- Carotid bruits correlate more closely with systemic atherosclerosis than with significant carotid stenosis, according to the American Heart Association guidelines published in Circulation 9
- Annual duplex ultrasonography is reasonable to assess progression or regression of disease in patients with atherosclerosis who have had stenosis greater than 50% detected previously, as suggested by the American College of Cardiology and the Journal of Neurointerventional Surgery 7, 8
Indications for Additional Testing
- If the patient develops neurological symptoms corresponding to the territory supplied by the carotid arteries, additional testing would be warranted, as recommended by the American College of Cardiology and the Journal of Neurointerventional Surgery 7, 8
- If future ultrasound surveillance shows progression to stenosis >50%, additional testing would be indicated, according to guidelines from the American College of Cardiology and the Journal of Neurointerventional Surgery 7, 8
- Avoid unnecessary testing in asymptomatic patients with mild stenosis, as it does not improve clinical outcomes, as stated in Circulation 9