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The goal of stroke prevention challenges healthcare systems and providers at multiple levels. The American Heart Association (AHA) estimates that 700,000 people experience stroke each year; 500,000 are new strokes and 200,000 are recurrent strokes. Stroke is the third leading cause of death in the United States. For stroke survivors, long-term disability may be catastrophic. The estimated direct and indirect costs of stroke in 2007 was $ 62.7 billion dollars in the United States. The incidence and prevalence of stroke in Tennessee, Kentucky, and Alabama is among the highest in our nation.

Carotid artery disease, especially atherosclerotic plaque located at or near the carotid bifurcation in the neck, accounts for up to 30% of ischemic strokes through mechanisms of atheroembolization and, less commonly, thrombosis. Risk factors include hypertension, diabetes, smoking, and hyperlipidemia. Control of all modifiable risk factors is essential in the management of patients with carotid atherosclerosis. Additionally, it must be recognized that plaque in the carotid arteries is a marker for systemic atherosclerosis and should focus the practitioner’s attention towards identification and management of disease in other vascular beds.

Carotid duplex ultrasonography (CDU) is a readily available, noninvasive examination which represents the primary diagnostic test for identification of carotid atherosclerosis and delineation of its severity. The decision to offer operative treatment for carotid artery stenosis, in selected cases, may be made solely on the basis of CDU findings and clinical history. However, confirmatory imaging studies are often required. Advances in noninvasive imaging techniques including magnetic resonance angiography (MRA) and computer tomographic angiography (CTA) have dramatically altered practice, providing information upon which treatment decisions may be based without subjecting patients to the risk of invasive angiography.

Carotid endarterectomy (CE) represents the gold standard for treatment of carotid artery disease. CE’s efficacy in stroke prevention was established through robust level-1 studies completed in the early and mid-1990s. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) clearly established the benefit of CE in preventing stroke in symptomatic patients having carotid stenoses greater than 70% in severity and even showed benefit to a lesser degree in cases of stenosis greater than 50%. Randomized, controlled trials in asymptomatic cohorts including the Asymptomatic Carotid Atherosclerosis Study (ACAS) demonstrated superiority of carotid endarterectomy over medical management in non high-risk patients having stenoses of 60% or greater. Both NASCET and ACAS were landmark studies which were stopped sooner than expected due to the superiority of surgery in relative and absolute risk reduction of stroke as compared to established medical management of their period.

It is important to note that best or optimal medical management (OMT) in NASCET and ACAS was not as well-defined as it is today. OMT includes not only anti-platelet therapy with aspirin or, in selected cases, combinations of aspirin and clopidogrel or dipyridamole but also includes aggressive use of “statins”, smoking cessation therapy, control of blood glucose in diabetics and control of hypertension. OMT is prescribed for all patients considered for invasive correction of carotid stenosis and is continued indefinitely following intervention.

Since the early 1990s, carotid artery stenting (CAS) has evolved as an alternative to CE for correction of carotid artery stenosis. The role of CAS is still being debated in high-risk surgical patients and certainly in those who are considered good surgical candidates. Clinical trials suggesting improved or equivalent outcomes produced by CAS as opposed to CE (SAPPHIRE) as well as trials suggesting inferiority of CAS as an alternative to CE (EVA-3S; SPACE) have been criticized on multiple levels.

The NINDS-sponsored Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) began enrollment in December 2000.This study compares safety and efficacy of the two treatment methods in both symptomatic and asymptomatic cohorts of standard patients and will likely guide government and third-party payment decisions affecting adoption of CAS into broad clinical practice. Until then, access to CAS will remain limited and CE will continue to be the standard of care.

At the Vanderbilt Heart and Vascular Institute, we have multiple ongoing CAS clinical registries and trials which allow patients considered to be high-risk surgical candidates access to all major platforms of stents and embolic protection devices. This provides us maximal flexibility in tailoring treatment to an individual patient’s anatomy and clinical needs.

For CAS to become a viable alternative to CE, it must be offered with equal safety. It is in this realm of practice that clinical judgement is of critical importance, for it is not infrequent that we encounter patients referred for CAS who, after careful consideration of clinical factors, plaque morphology, and anatomy, are found to be at greater risk for complications with CAS than with CE.

All other factors being equal, nonbiased selection based on comprehensive assessment of an individual patient’s risk profile represents the key to superior treatment outcomes.



Guidelines for prevention of stroke in patients with ischemic stroke or TIA. Stroke 2006; 37:577-617



Presented in Partnership by Nashville Medical News and Vanderbilt University Medical Center



June 2008

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