New Guideline - Doença arterial carotídea e vertebral

From http://www.theheart.org/

The American College of Cardiology, American Heart Association, and Society for Cardiovascular Angiography and Interventions, in conjunction with a range of other medical societies, released new guidelines on the use of stenting and surgery in the management of patients with extracranial carotid and vertebral artery disease [1].

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 of complications, with stenosis greater than 70% on duplex ultrasonography.

Dr Thomas G Brott (Mayo Clinic Jacksonville, FL) was cochair of the writing committee for the new guidelines and also principal investigator of the Carotid Revascularization Endarterectomy Versus Stenting 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 Food and Drug Administration Circulatory System Devices Panel, Brott said, which voted 7 to 3 in favor of an expanded indication for the RX Acculink Carotid Stent System (Abbott, Abbott Park, IL), 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 three 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," Brott said in an interview.

The guidelines suggest it maybe "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, 2011 in Circulation, Stroke, and the Journal of the American College of Cardiology.

Routine screening not recommended

The new recommendations deal with diagnostic testing, medical and surgical therapies, and risk-factor modification in patients with extracranial carotid and vertebral artery disease.

Some of their other recommendations include:

•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 MI 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 (TIA), 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 CABG is reasonable in patients over 65 and those with left main coronary stenosis, a history of stroke or TIA, 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 is "not well established."

"Vast opportunities" for research

Although the 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 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."

1.Brott TG, Halperin JL, Abbara S, et al. JASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease: Executive summary. Circulation 2011: DOI:10.1161/CIR.0b013e31820d8d78. Available at: http://circ.ahajournals.org. Stroke 2011;DOI:10.1161/STR.0b013e3182112d08. Available at: http://stroke.ahajournals.org. J Am Coll Cardiol 2011; DOI:10.1016/j.jacc.2010.11.006. http://content.onlinejacc.org.