New Guidelines on Carotid and Vertebral Artery Disease

News Author: Susan Jeffrey
CME Author: Charles P. Vega, MD

CME Released: 02/11/2011; Valid for credit through 02/11/2012

February 11, 2011 — New guidelines on the management of patients with extracranial carotid and vertebral artery disease (ECVD) were released on January 31 by the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines.

The document was developed in collaboration with a gamut of other organizations, including the 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, and Society for Vascular Surgery, as well as the American Academy of Neurology and Society of Cardiovascular Computed Tomography.

Of note are new recommendations for management of carotid disease, where carotid stenting is now seen as an alternative to carotid endarterectomy for symptomatic patients at average or low risk for complications, with stenosis greater than 70% on duplex ultrasonography.

Thomas G. Brott, MD, professor of neurology and director of research at the Mayo Clinic in Jacksonville, Florida, was cochair of the writing committee for the new guidelines and also principal investigator of the Carotid Revascularization Endarterectomy versus Stent Trial (CREST).

The results of CREST suggest that in addition to carotid surgery and medical therapy, "we now have a third option, carotid stenting, he said. "Both surgery and stenting have been shown to be safe, and so far, in CREST, both have been shown to be durable."

The new guidelines are concordant with recently released guidelines on primary and secondary stroke prevention, as well as a recommendation last week by the US Food and Drug Administration Circulatory System Devices Panel, Dr. Brott said. At a meeting January 26, the panel voted 7 to 3 in favor of an expanded indication for the RX Acculink Carotid Stenting System, stating the benefits of carotid stenting in patients at standard risk for adverse events from endarterectomy outweigh the risks. Currently, the system is approved only for those at high surgical risk.

The role of stenting vs surgery has been controversial, given results of previous randomized comparisons, such as the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) trial and the International Carotid Stenting Study (ICSS), that had suggested surgery to be the safer option.

"I would say in other situations where we have 3 choices for treatment of a particular condition, physician groups and patients don't always agree on the options for a particular patient, and that's likely to occur with carotid disease as well," Dr. Brott said in an interview.

The guidelines suggest it may be "reasonable" to choose surgery over stenting in older patients, particularly those with anatomy unfavorable for stenting, and likewise reasonable to choose stenting over surgery when neck anatomy is not suitable for surgery.

The document is published online January 31 in Circulation: Journal of the American Heart Association, Stroke: Journal of the American Heart Association, and Journal of the American College of Cardiology.

Routine Screening Not Recommended

The new recommendations deal with diagnostic testing and medical and surgical therapies, as well as risk factor modification, in patients with ECVD.

Some of their other recommendations include the following:

• The guidelines advocate duplex ultrasonography, performed by a qualified technologist in a certified laboratory, as the initial diagnostic test for suspected carotid stenosis. However, the writing group recommends against routine screening of asymptomatic patients without clinical symptoms or risk factors for atherosclerosis.
• In patients with extracranial carotid disease not undergoing revascularization, the guidelines recommend antiplatelet therapy with aspirin, 75 to 325 mg daily, for patients with obstructive or nonobstructive atherosclerosis in extracranial carotid and/or vertebral arteries for prevention of myocardial infarction and other cardiovascular events. The benefit of treatment to prevent stroke in asymptomatic patients hasn't been established, they note.
• For those with extracranial carotid or vertebral atherosclerosis with a history of ischemic stroke or transient ischemic attack, antiplatelet therapy with aspirin alone (75 to 325 mg daily), clopidogrel alone (75 mg daily), or the combination of aspirin plus extended-release dipyridamole (25 and 200 mg twice daily, respectively) is recommended and preferred over the combination of aspirin with clopidogrel.
• Carotid duplex ultrasound screening before coronary artery bypass grafting is reasonable in patients older than 65 years, those with left main coronary stenosis, and a history of stroke or transient ischemic attack or carotid bruit. Revascularization with surgery or stenting with embolic protection is reasonable for those who have experienced ipsilateral ischemic symptoms, but for asymptomatic patients, the safety and efficacy of carotid revascularization before or during CABG are "not well established."

'Vast Opportunities' for Research

Although the study authors note that their recommendations are "whenever possible, evidence based," review of the literature has shown that great gaps in knowledge remain.

"As evident from the number of recommendations in this document that are based on consensus in a void of definitive evidence, there are vast opportunities for research," they write.

Among these is the lack of evidence to support the benefit of carotid surgery in women, a clear need for more information on the "imperfect correlation" between the severity of carotid stenosis and ischemic events, and better methods to improve diagnostic accuracy of stenosis.

"CREST answered some questions about the relative value of [carotid artery stenting and carotid endarterectomy] but raised others," they write. "The reported event rates were generally low with either method of revascularization among symptomatic patients, but there was an important difference related to patient age that requires explanation.

"The most pressing question is how either technique of revascularization compares with intensive contemporary medical therapy, particularly among asymptomatic patients, and a direct comparative trial should include a sufficiently broad range of patients to permit meaningful analysis of subgroups based on age, sex, ethnicity, and risk status," the study authors write.

"Huge gaps" in knowledge about vertebral arterial disease will be more difficult to solve because of its relative infrequency compared with carotid stenosis, they add. "This requires well-designed registries that capture data about prevalence, pathophysiology, natural history, and prognosis."

Dr. Brott reports having received research funding from Abbott and the National Institutes of Health as principal investigator of CREST. Dr. Halperin reports serving as a consultant to Astellas Pharma, Bayer Health Care, Biotronik, Boehringer Ingelheim, Daiichi Sankyo, the US Food and Drug Administration Cardiovascular and Renal Drugs Advisory Committee, GlaxoSmithKline, Johnson & Johnson, Portola, and Sanofi-aventis. He has also received research funding from the National Heart, Lung, and Blood Institute. Disclosures for other members of the writing committee appear in the document.

J Am Coll Cardiol. Published online January 31, 2011. Full text

Stroke. Published online January 31, 2011. Full text

Circulation. Published online January 31, 2011. Full text

http://www.medscape.org/viewarticle/737243?src=cmemp

regards, taniafdi ^_^