2007 Carotid Screening Guidelines – Overvalued

Medscape PUBLISHED: March 2007

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Medscape's article on “New Guidelines for Carotid Screening” is misleading and widely off target.[1] Adnan Qureshi, the lead author of the guidelines, said, “we have evidence that if you detect this [asymptomatic carotid] stenosis early and treat it by either surgery or endovascular treatment, you can actually prevent a stroke from happening.” This statement is outdated for surgery and completely unfounded for endovascular treatment.

All level I evidence that carotid endarterectomy (CEA) diminishes stroke risk is based on randomized comparisons with outdated best medical therapy, which does not include systematic use of newer antiplatelet agents and statins,[24] and we know that statins decrease stroke risk in atherosclerotic patients.[5,6] Moreover, there is no level I evidence comparing carotid stenting (CAS) with current medical treatment. Asymptomatic carotid disease is far more benign than symptomatic carotid stenoses. Although both CEA and CAS have low procedural risks in asymptomatic patients, older studies show that the long-term stroke risk for even outdated medical treatment is also low (2% to 3% per year).[3,4] With modern medical treatment it may be lower, even lower than that of CEA and CAS, which carry late stroke risks around 1% per year in addition to their procedural risks.[3,4]

Although there may be justification for carotid screening in some high-risk patient groups, the presumption cannot be made that CEA or CAS for asymptomatic carotid stenoses will prevent more strokes than best current medical treatment. That presumption must be validated by level I evidence in which vintage 2007 medical therapy is compared with CEA and CAS for asymptomatic stenoses. Such a study, the TACIT trial, has been designed but remains unfunded. Until the results of such a trial become known, it is more important to stress the value of good medical therapy rather than widespread carotid screening in asymptomatic patients at risk for arteriosclerosis.

That's my opinion, and I'm Dr. Frank Veith, Professor of Surgery at The Cleveland Clinic and New York University School of Medicine.

Footnotes

Readers are encouraged to respond to the author at moc.nsm@dmvjf or to Paul Blumenthal, MD, Deputy Editor of MedGenMed, for the editor's eyes only or for possible publication via email: ude.drofnats@nemulbp

References

1. Jeffrey S, Vega C. New guidelines issued for carotid screening. Medscape Medical News. Copyright 2007. Available at: http://www.medscape.com/viewarticle/551335 Accessed March 12, 2007.
2. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high grade carotid stenosis. N Engl J Med. 1991;325:445–453. [PubMed]
3. Hobson RW, Weiss DG, Fields WS, et al. Efficacy of carotid endarterectomy for asymptomatic carotid stenosis. The Veterans Affairs Cooperative Study Group. N Engl J Med. 1993;328:221–217. [PubMed]
4. Halliday A, Mansfield A, Marro J, et al. Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without neurological symptoms: randomized controlled trial. Lancet. 2004;363:1491–1502. [PubMed]
5. Amarenco P, Labreuche J, Lavallee P, Touboul P-J. Statins in stroke prevention and carotid atherosclerosis: systematic review and meta-analysis. Stroke. 2004;35:2902–2909. [PubMed]
6. The Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Investigators. High-dose atorvastatin after stroke or transient ischemic attack. N Engl J Med. 2006;355:549–559. [PubMed]