Clinical Review

Management of Carotid Artery Disease

Endarterectomy Versus Stenting

Clinician Reviews. 2010 January;20(1):21, 24, 26, 27

Author(s):

Carotid artery stenosis (CAS) may cause 20% of ischemic strokes. Which patients are at risk, which should be screened—and what treatment option is most suitable for your patient with CAS?

References

1. Goldstein LB, Adams R, Alberts MJ, et al. Primary prevention of ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council: cosponsored by the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group; Cardiovascular Nursing Council; Clinical Cardiology Council; Nutrition, Physical Activity, and Metabolism Council; and the Quality of Care and Outcomes Research Interdisciplinary Working Group: the American Academy of Neurology affirms the value of this guideline. Stroke. 2006;37(6):1583–1633.

2. American Heart Association. Heart Disease and Stroke Statistics—2004 Update. www.americanheart.org/downloadable/heart/1079736729696HDSStats2004UpdateREV3-19-04.pdf. Accessed December 28, 2009.

3. Society for Vascular Surgery. SVS position statement on vascular screenings. www.vascularweb.org/patients/screenings/SVS_Position_Statement_on_Vascular_Screenings.html. Accessed December 28, 2009.

4. Wolff T, Guirguis-Blake J, Miller T, et al. Screening for carotid artery stenosis: an update of the evidence for the US Preventive Services Task Force. Ann Intern Med. 2007;147(12):860- 870.

5. Colgan MP, Strode GR, Sommer JD, et al. Prevalence of asymptomatic carotid disease: results of duplex scanning in 348 unselected volunteers. J Vasc Surg. 1988;8(6):674-678.

6. Pujia A, Rubba P, Spencer MP. Prevalence of extracranial carotid artery disease detectable by echo-Doppler in an elderly population. Stroke. 1992;23(6):818-822.

7. Gurm HS, Yadav JS, Fayad P, et al; SAPPHIRE Investigators. Long-term results of carotid stenting versus endarterectomy in high-risk patients. N Engl J Med. 2008;358(15):1572-1579.

8. US Preventive Services Task Force. Screening for carotid artery stenosis: US Preventive Services Task Force Recommendation Statement. Ann Intern Med. 2007;147(12):854-859.

9. Qureshi AI, Alexandrov AV, Tegeler CH, et al. Guidelines for screening of extracranial carotid artery disease: a statement for healthcare professionals from the multidisciplinary practice guidelines committee of the American Society of Neuroimaging; cosponsored by the Society of Vascular and Interventional Neurology. J Neuroimaging. 2007;17(1):19-47.

10. Ferguson GG, Eliasziw M, Barr HWK, et al. The North American Symptomatic Carotid Endarterectomy Trial. Stroke. 1999;30(9):1751-1758.

11. Rothwell PM, Gutnikov SA, Warlow CP; European Carotid Surgery Trial. Reanalysis of the final results of the European Carotid Surgery Trial. Stroke. 2003;34(2):514-23.

12. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA. 1995;273(18):1421-1428.

13. Hobson RW 2nd, Mackey WC, Ascher E, et al; Society for Vascular Surgery. Management of atherosclerotic carotid artery disease: clinical practice guidelines of the Society for Vascular Surgery. J Vasc Surg. 2008;48(2):480-486.

14. Halm EA, Tuhrim S, Wang JJ, et al. Risk factors for perioperative death and stroke after carotid endarterectomy: results of the New York Carotid Artery Surgery Study. Stroke. 2009;40(1):221-229.

15. Halliday A, Mansfield A, Marro J, et al; MRC Asymptomatic Carotid Surgery Trial (ACST). Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: randomised controlled trial. Lancet. 2004;363(9420):1491-1502.

16. Yadav JS, Wholey MH, Kuntz RE, et al; Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy Investigators (SAPPHIRE). Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med. 2004;351(15):1493-1501.

17. Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): a randomised trial. Lancet. 2001;357: 1729–1737.

18. Massop D, Dave R, Metzger C, et al. Stenting and angioplasty with protection in patients at high-risk for endarterectomy: SAPPHIRE Worldwide Registry first 2,001 patients. Catheter Cardiovasc Interv. 2009;73(2):129-136.

19. Barbato JE, Dillavou E, Horowitz MB, et al. A randomized trial of carotid artery stenting with and without cerebral protection. J Vasc Surg. 2008;47(4):760-765.

20. Suliman A, Greenberg J, Chandra A, et al. Carotid endarterectomy as the criterion standard in high-risk elderly patients. Arch Surg. 2008; 143(8):736-742.

21. Hobson RW 2nd, Howard VJ, Roubin GS, et al. Carotid artery stenting is associated with increased complications in octogenarians: 30-day stroke and death rates in the CREST lead-in phase. J Vasc Surg. 2004;40(6):1106-1111.

22. Lal BK, Brott TG. The Carotid Revascularization Endarterectomy vs. Stenting Trial completes randomization: lessons learned and anticipated results. J Vasc Surg. 2009;50(5):1224-1231.

23. Derdeyn CP. Carotid stenting for asymptomatic carotid stenosis: trial it. Stroke. 2007;38(2 suppl):715-720.

24. Guyatt GH, Oxman AD, Vist GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008;336(7650):924-926.

25. Sacco RL, Adams R, Albers G, et al. Guidelines for prevention of stroke in patients with ischemic stroke or transient ischemic attack: a statement for healthcare professionals from the American Heart Association/American Stroke Association Council on Stroke: co-sponsored by the Council on Cardiovascular Radiology and Intervention: the American Academy of Neurology affirms the value of this guideline. Stroke. 2006;37(2):577-617.

Carotid artery disease is a treatable cause of ischemic stroke, a potentially devastating event that affects approximately 700,000 Americans each year and results in more than 160,000 deaths.^1,2 Stroke-related medical costs, including associated disability, now approach $60 billion per year. Despite advances in treatment, stroke remains the third leading cause of death in the United States.³

As the population ages, stroke prevention has become an increasing challenge for primary care providers. Guiding patients at risk toward the appropriate testing and treatment can offer lifelong benefits. This article will summarize current practice recommendations for screening asymptomatic individuals and for treatment of carotid artery disease using carotid endarterectomy or carotid angioplasty with stenting.

Scope and Screening
Carotid artery stenosis (CAS) is defined as atherosclerotic narrowing of the extracranial carotid arteries. Possibly 20% of ischemic strokes (which represent more than 85% of all strokes) result from CAS, a condition that may or may not be symptomatic.⁴Symptomatic CAS may be represented by a cerebrovascular accident, a transient ischemic attack, or one of an array of more subtle but enduring neurologic deficits.

The prime risk factor for CAS is prior history of cerebrovascular disease.⁴ Cardiovascular disease or cigarette smoking doubles a patient’s risk for developing CAS. Other risk factors include age greater than 65, male gender, hypertension, atrial fibrillation, and clotting disorders.

Population studies based on carotid ultrasonography estimate the prevalence of CAS at 0.5% to 8.0% in the general population.^4-6 Clinically significant CAS (60% or higher) has been estimated at 1% in those older than 65.⁴

The degree of carotid occlusion correlates directly with the risk of ipsilateral stroke. The rate of stroke among asymptomatic patients with CAS of at least 80% is 3.5% to 5.0% per year.⁷ To date, there is no clinically useful risk model to identify those who have CAS or will develop it.

Screening the general population for asymptomatic CAS is not currently recommended.^4,8 Guidelines published in 2007 by the Society for Vascular Surgery (SVS)³ advise ultrasound screening only for persons 55 and older who have cardiovascular risk factors, including diabetes, hypertension, hypercholesterolemia, a history of smoking, or known cerebrovascular disease. That same year, the American Society of Neuroimaging⁹ recommended screening of adults 65 or older who have three or more cardiovascular risk factors.

Ultrasound screening is approximately 94% sensitive and 92% specific for moderate to severe CAS (ie, 60% to 90% occlusion).⁴ Patients with positive ultrasound findings may next undergo computerized axial angiography, magnetic resonance angiography, or digital subtraction angiography.

Angiography can detect with good precision the degree and location of carotid occlusion, which in turn helps to select treatment options, in consideration of their inherent risks and benefits. These options are medical therapy alone, or medical therapy combined with carotid endarterectomy (CEA), or carotid angioplasty with stenting.

The Research
Stroke prevention, long since a medical priority, is most commonly sought by way of pharmacotherapy combined with lifestyle modification. Surgery, in the form of CEA, also plays an enduring and proven role. Randomized trials, including three landmark studies,^10-12 have established CEA as standard treatment for symptomatic and high-grade occlusive carotid disease. The North American Symptomatic Carotid Endarterectomy Trial (NASCET)¹⁰ and the European Carotid Surgery Trial (ECST)¹¹ provided the basis for stratifying symptomatic patients and determining whether surgery will produce a reasonable benefit. The Asymptomatic Carotid Atherosclerosis Study (ACAS)¹² extended the research to asymptomatic patients with high-grade stenosis.^8,13 The benefits of CEA for elderly patients (75 and older) with significant comorbidities were supported in the 2009 New York Carotid Artery Surgery Study (NYCAS).¹⁴

Researchers for ACAS,¹² which compared medical therapy alone with CEA plus medical therapy in asymptomatic patients with CAS, reported a relative risk (RR) reduction of 0.53 in patients undergoing CEA, with a 5.1% five-year rate of stroke or death in the CEA group versus 11.0% among patients receiving medical therapy alone. The Asymptomatic Carotid Surgery Trial¹⁵ (ACST) yielded similar event rates (CEA, 6.4%; medical therapy alone, 11.8%). In both trials, the perioperative (30-day) risk of stroke or death associated with CEA ranged from 2.7% to 3.1%. In the long term (five to 10 years and beyond), RR reduction remains uncertain.

However, CEA remains the gold standard for the treatment of severe carotid artery disease. Currently, about 75% of patients who undergo CEA for significant CAS are asymptomatic.¹³

Complications associated with CEA occur at an ascending rate, commensurate with the patient’s preoperative stroke history. Researchers for the NYCAS¹⁴ reported a 30-day post-CEA rate of stroke or death of nearly 3% among asymptomatic patients with no history of stroke or TIA; nearly 8% among patients with previous stroke; and more than 13% in patients with crescendo TIA or evolving stroke. A significant increase in complications (including stroke or death) was reported among patients with coronary artery disease or with diabetes requiring insulin therapy.