Experts address the appropriate use of contemporary imaging and revascularization techniques and identify important gaps in the evidence base to guide future research.
Sponsoring Organizations: American College of Cardiology, American Heart Association, American Stroke Association, American Association of Neuroscience Nurses, American Association of Neurological Surgeons, American College of Radiology, American Society of Neuroradiology, Congress of Neurological Surgeons, Society of Atherosclerosis Imaging and Prevention, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, Society for Vascular Medicine, Society for Vascular Surgery, American Academy of Neurology, Society of Cardiovascular Computed Tomography
Background and Purpose: These new guidelines on caring for patients with extracranial carotid and vertebral artery disease (ECVD) provide recommendations for diagnostic testing, modification of risk factors, and medical and surgical therapies, focusing on the use of stenting and surgery for carotid revascularization.
Key Points:
1. Population screening for asymptomatic carotid artery stenosis is not recommended (Class III, level C).
2. Duplex ultrasonography is the recommended initial diagnostic test in asymptomatic patients with known or suspected carotid artery stenosis (Class I, level C).
3. Duplex ultrasonography is also the recommended initial diagnostic test in patients with focal neurological symptoms corresponding to the territory supplied by the left or right internal carotid artery (Class I, level C).
4. Magnetic resonance angiography or computed tomography angiography is recommended in symptomatic patients when sonography either is unavailable or yields uncertain results (Class I, level C).
5. Recommendations for the medical management of ECVD include:
- Blood pressure control to <140/90 mm Hg (Class I, level A)
- Smoking cessation (Class I, level B)
- Statin therapy to reduce LDL level to <100 mg/dL (Class I, level B) or to
70 mg/dL in patients with diabetes (Class IIa, level B) - In patients with diabetes, diet, exercise, and glucose-lowering treatment; however, stroke prevention benefit has not been demonstrated at glycosylated hemoglobin A1c levels <7% (Class IIa, level A).
6. Regarding antithrombotic therapy for ECVD:
- Aspirin, 75 to 325 mg daily, is recommended for prevention of myocardial infarction and other cardiovascular events; however, no benefit has been demonstrated for primary prevention of stroke (Class I, level A).
- After stroke or transient ischemic attack (TIA), aspirin (75 to 325 mg daily), clopidogrel (75 mg daily), or the combination of aspirin and extended-release dipyridamole (25 mg and 200 mg twice daily, respectively) is recommended and preferable to the combination of aspirin and clopidogrel, which increases hemorrhagic risk (Class I, level B).
7. In patients with symptomatic carotid stenosis, the choice between stenting and surgery has been controversial. Upon reviewing the evidence, the authors conclude that choosing surgery over stenting is reasonable in older patients, particularly when arterial anatomy is unfavorable for stenting; similarly, choosing stenting over surgery is reasonable when neck anatomy is unsuitable for surgery (Class IIa, level B).
8. Carotid duplex ultrasound screening before coronary artery bypass grafting is reasonable in patients aged >65 and in those with left main coronary stenosis, a history of stroke or TIA, or carotid bruit (Class IIa, level C); however, the safety and efficacy of carotid revascularization before or during myocardial revascularization remain unproven in asymptomatic patients (Class IIb, level C).
Comment: These recommendations concur with recently released guidelines on primary and secondary stroke prevention. The main message about revascularization for symptomatic carotid stenosis is that stenting should be avoided in older patients (e.g., aged 
70) but might be as safe as endarterectomy in younger patients. However, a more important question is how either revascularization technique compares with intensive contemporary medical therapy, particularly in asymptomatic patients. As evidenced by the number of recommendations that are based on consensus in the absence of definitive evidence, opportunities for further research abound (e.g., the “imperfect correlation” between severity of carotid stenosis and ischemic events, methods to improve diagnostic accuracy, the effectiveness of carotid surgery in women). Large gaps in knowledge about vertebral arterial disease will be difficult to fill because of its relative infrequency compared with carotid artery disease.
Published in Journal Watch Cardiology March 16, 2011
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