CAROTID ARTERY STENOSIS

Mark Tuttle 2014

EPIDEMIOLOGY ● 0.2% prevalence in men < 50, 7.5% prevalence in men > 80​8 ● 0-5% in women​8 PATHOPHYSIOLOGY ● Plaque usually arises at the carotid bifurcation due to turbulent flow from the carotid bulb​8 CLINICAL TRIALS Asymptomatic Carotid Stenosis  ● VA​5​: ​Veterans Affairs Cooperative Study Group (1993) ○ Inclusion criteria​: Asymptomatic carotid stenosis > 50% by arteriogram ○ Exclusion criteria​: History of stroke, life expectancy < 5 years ○ Randomization​: 444 men randomized to CEA vs. medical therapy ○ Outcomes​ ⇒ Reduced risk of first stroke with endarterectomy when stenosis > 50% ■ TIA, transient blindness, or any stroke at ~4 years: 24.5% (medical) vs. 12.8% (CEA) p<0.002 ■ No difference in overall mortality ● ACAS​3​: Asymptomatic Carotid Atherosclerosis Study (1995) ○ Inclusion criteria​: Asymptomatic carotid stenosis > 60% by any method, 40-79 years old ○ Exclusion criteria​: History of stroke ○ Randomization​: 1,662 randomized to CEA vs. medical therapy ○ Outcomes​ ⇒ Reduced risk of first stroke with endarterectomy when stenosis > 60% ■ Ipsilateral stroke at 5 years: 11% (medical) vs. 5.1% (CEA) p=0.04 ■ No difference in major stroke (resulting in moderate or severe disability, persistent vegetative state, or death) or death (p=0.16) ■ No difference in overall mortality ● ACST​4​: Asymptomatic Carotid Surgery Trial (2004) ○ Inclusion criteria​: Asymptomatic carotid stenosis > 60% by any method, <75 years old ○ Exclusion criteria​: History of stroke, high surgical risk ○ Randomization​: 3,120 randomized to CEA vs. medical therapy ○ Outcomes​ ⇒ Reduced risk of first stroke with endarterectomy when stenosis > 70% ■ Any stroke at 5 years: 6.4% (CEA) vs. 11.8 (medical), p<0.0001 ■ Fatal or disabling stroke at 5 years: 3.5% (CEA) vs. 6.1% (medical), p,0.004 ■ Fatal stroke at 5 years: 2.1% (CEA) vs. 4.2% (medical), p=0.006 Symptomatic carotid stenosis  ● NASCET​2​: North American Symptomatic Carotid Endarterectomy Trial Collaborators (1998) ○ Inclusion criteria​: Symptomatic (TIA or CVA on ipsilateral side) stenosis <70%, Rankin score < 3 ○ Exclusion criteria​: Age > 80, life expectancy < 5 years ○ Randomization​: 2,226 randomized to CEA vs. medical therapy ○ Outcomes​ ⇒ Reduced risk of recurrent stroke with endarterectomy when stenosis > 50% ■ Ipsilateral stroke at 5 years ● With 70-99% stenosis: 9% vs. 26% (stopped early due to clear benefit) ● With 50-69% stenosis: 15.7% vs. 22.2% (RR 0.71; 95% CI 0.48-0.93; P=0.045), NNT=15 ● With <50% stenosis: 14.9% vs. 18.7% (P=0.16) Carotid endarterectomy versus stenting  ● CREST​1​: Carotid Revascularization Endarterectomy vs. Stenting Trial (2010) ○ Inclusion criteria​: Symptomatic OR asymptomatic carotid stenosis > 60%-70% ○ Exclusion criteria​: Prior stroke, atrial fibrillation, ACS in prior 30 days ○ Randomization​: 2,502 randomized to stenting vs. CEA ○ Outcomes​ ⇒ No difference between endarterectomy or stenting in the composite endpoint ■ Composite (any stroke, MI, or death periprocedurally or ipsilateral stroke within 4 years) ● Periprocedurally: 5.2% vs. 4.5% (HR 1.18; 95% CI 0.82-1.68; P=0.38) ● Four year follow up: 7.2% vs. 6.8% (HR 1.11; 95% CI 0.81-1.51; P=0.51) MarkTuttleMD.com

CAROTID ARTERY STENOSIS

Mark Tuttle 2014

MAJOR SOCIETY GUIDELINES  AHA Guidelines  ● Management of Asymptomatic Carotid Artery Stenosis​6 ○ All patients should initiate lifestyle changes, medical therapy, and reduction of risk factors (Class I; Level of Evidence C) ○ A thorough discussion of life expectancy, individual factors, risks/benefits should take place (Class I; Level of Evidence C) ○ If CEA is selected, aspirin should be used concurrently (Class I; Level of Evidence C) ○ Prophylactic CEA performed with <3% morbidity & mortality can be useful in highly selected patients with asymptomatic carotid stenosis (>60% by angiography or >70% by doppler ultrasound) (Class IIa; Level of Evidence A). The benefit of surgery may now be lower due to advances in medical therapy. ○ Propohylactic carotid artery stenting might be considered in highly selected patients with carotid stenosis (>60% by angiography, >70% on doppler ultrasound, or >80% by CT or MRA). However, the advantage of stenting over current medical therapy alone is not well established. (Class IIb; Level of Evidence B) ○ The usefulness of CAS as an alternative to CEA in asymptomatic patients at high risk for the surgical procedure is uncertain (Class IIb; Level of Evidence C). ○ Population screening for asymptomatic carotid artery stenosis is not recommended (Class III; Level of Evidence B). ○ Revascularization is not recommended for chronic total occlusion (Class III; Level of Evidence C)​7 ● Management of symptomatic carotid stenosis​7 ○ Patients at low-average surgical risk who have TIA or nondisabling stroke (≤ 2 Modified Rankin Scale) within 6 months should undergo CEA if stenosis >70%. (Class I; Level of Evidence A) or> 50% by angiography (Class I; Level of Evidence b) and the anticipated rate of perioperative stroke or mortality is less than 6%. SOURCES:  1. Brott TG, Hobson RW, Howard G, et al. Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med. 2010;363(1):11-23. 2. Barnett HJ, Taylor DW, Eliasziw M, et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators. N Engl J Med. 1998;339(20):1415-25. 3. Endarterectomy for asymptomatic carotid artery stenosis. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. JAMA. 1995;273(18):1421-8. 4. Halliday A, Mansfield A, Marro J, et al. Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: randomised controlled trial. Lancet. 2004;363(9420):1491-502. 5. 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(4):221-7. 6. Goldstein LB, Bushnell CD, Adams RJ, et al. Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2011;42(2):517-84. 7. Brott TG, Halperin JL, Abbara S, et al. 2011 ASA/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: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, and 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. J Am Coll Cardiol. 2011;57(8):1002-44. 8. Daly C, Rodriguez HE. Carotid artery occlusive disease. Surg Clin North Am. 2013;93(4):813-32, viii.

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