New guidelines for managing extracranial carotid and vertebral artery disease recommend against routine screening for obstruction, and advocate ultrasound examination only in patients who are symptomatic or have at least risk two factors for stroke.
The guidelines also state that based on current evidence, carotid endarterectomy and carotid stenting appear to be equally "reasonable and safe" for patients found to have more than 50% blockage, with the choice between the two approaches dictated by individual factors such as patient anatomy, comorbidities, and stroke risk, wrote cochairs Dr. Jonathan L. Halperin, professor of medicine at Mount Sinai School of Medicine, New York, and Dr. Thomas G. Brott, professor of neurology and director of research at the Mayo Clinic, Jacksonville, Fla., and their colleagues on the writing committee.
The new guidelines, issued jointly by the American Heart Association, American Stroke Association, American College of Cardiology, and other expert groups, "are intended to assist the diverse array of clinicians who provide care for patients with ECVD [extracranial carotid and vertebral artery disease]" and include a comprehensive review of the most recent literature. They detail dozens of recommendations for diagnostic testing, treatment of contributing factors such as hypertension and hyperlipidemia, selecting patients for carotid revascularization, managing restenosis, and handling anatomic abnormalities and special patient populations (J. Am. Coll. Cardiol. 2011 [doi.10.1016/j.jacc.2010.11005]).
Among these recommendations:
• Duplex ultrasonography is the initial diagnostic test of choice for detecting hemodynamically significant carotid stenosis. It is "reasonable" to use this technique in asymptomatic patients if they have a carotid bruit; symptomatic coronary artery disease, peripheral artery disease, or atherosclerotic aortic aneurysm; or at least two of the following risk factors: hypertension, hyperlipidemia, smoking, family history of atherosclerosis manifested before age 60, and family history of ischemic stroke.
• Carotid stenting and carotid endarterectomy are similarly safe for treating obstructions of 50% or more. Physicians and patients should decide between the two procedures on an individual basis, taking into account surgical risk, comorbidities, life expectancy, patient preferences, neck anatomy, and other factors.
• "The value of specific therapies to prevent stroke, even in symptomatic patients with severe carotid artery stenosis, largely lacks validation." Antiplatelet therapy reduces stroke risk in patients with transient ischemic attack or previous stroke, but "no adequately powered studies have demonstrated their efficacy for stroke prevention in asymptomatic patients with ECVD." Similarly, the use of anticoagulants in ECVD patients who develop stroke has not been explored.
• It remains unclear whether women benefit as much as men do from carotid endarterectomy. Information also is lacking for other important subsets of patients, including the elderly and various racial/ethnic groups.
• "The most pressing question is how either technique of revascularization compares with intensive contemporary medical therapy, particularly among asymptomatic patients." A clinical trial that directly compares the three approaches "should include a sufficiently broad range of patients to permit meaningful analysis of subgroups based on age, sex, ethnicity, and risk status."
Regarding vertebral artery disease, the guidelines state that its infrequency relative to carotid artery disease has made for "huge gaps in knowledge." Registries to capture data on the prevalence, pathophysiology, prognosis, and natural history of vertebral artery disease would be an important first step in addressing these gaps, the authors noted.
The executive summary and the full guidelines are available at www.cardiosource.org and my.americanheart.org and are being co-published in Circulation, Catheterization and Cardiovascular Interventions, the Journal of Cardiovascular Computed Tomography, the Journal of NeuroInterventional Surgery, the Journal of Vascular Surgery, and Vascular Medicine.
Most of the members of the writing committee disclosed ties to pharmaceutical and/or device companies. A complete list of those relations, and those of the peer reviewers, is in the executive summary.