Table 3. Guideline based recommendations for carotid endarterectomy.

	ACC/AHA guidelines (2011)79)	SVS guidelines (2011)82)	ESVS guidelines (2009)81)	ESC guidelines (2011)80)
Symptomatic	Patients at average or low surgical risk who experience nondisabling ischemic stroke or transient cerebral ischemic symptoms, including hemispheric events or amaurosis fugax, within 6 months (symptomatic patients) should undergo CEA if the diameter of the lumen of the ipsilateral internal carotid artery is reduced more than 70% as documented by noninvasive imaging [class I; level of evidence A] or more than 50% as documented by catheter angiography [class I; level of evidence B] and the anticipated rate of perioperative stroke or mortality is less than 6%.	In the majority of patients with carotid stenosis who are candidates for intervention, CEA is preferred to CAS for reduction of all cause stroke and periprocedural mortality. [grade I; level of evidence B] Data from CREST suggest that patients < 70 years of age may be better treated by CAS. These data need further confirmation.	The operative treatment of carotid disease is absolutely indicated in symptomatic patients with > 70% (NASCET) stenosis and probably with > 50% (NASCET) stenosis. The perioperative stroke/death rate should be < 6%. [level of evidence A]	In patients with symptomatic 70–99% stenosis of the internal carotid artery, CEA is recommended for the prevention of recurrent stroke. [class I; level of evidence A] In patients with symptomatic 50–69% stenosis of the internal carotid artery, CEA should be considered for recurrent stroke prevention, depending on patient-specific factors. [class IIa; level of evidence A]
Asymptomatic	Selection of asymptomatic patients for carotid revascularization should be guided by an assessment of comorbid conditions, life expectancy, and other individual factors and should include a thorough discussion of the risks and benefits of the procedure with an understanding of patient preferences. [class I; level of evidence C] It is reasonable to perform CEA in asymptomatic patients who have more than 70% stenosis of the internal carotid artery if the risk of perioperative stroke, MI, and death is low. [class IIa; level of evidence A]	Neurologically asymptomatic patients with equal or > 60% diameter stenosis, should be considered for CEA for reduction of long-term risk of stroke provided the patient has a 3- to 5-year life expectancy and perioperative stroke/death rates can be equal to or < 3%. [grade I; level of evidence A].	CEA can be recommended for asymptomatic men below 75 years with 70–99% stenosis if the risk associated with surgery is less than 3%. [level of evidence A] The benefit from CEA in asymptomatic women with carotid stenosis is significantly less than in men. CEA should therefore be considered only in younger, fit women. [level of evidence A]	In asymptomatic patients with carotid artery stenosis ≥ 60%, CEA should be considered as long as the perioperative stroke and death rate for procedures performed by the surgical team is < 3% and the patient's life expectancy exceeds 5 years. [class IIa; level of evidence A]

ACC, American College of Cardiology; AHA, American Heart Association; SVS, Society for Vascular Surgery; ESVS, European Society for Vascular Surgery; ESC, European Society for Cardiology; CEA, carotid endarterectomy; CAS, carotid artery stenting; MI, myocardial infarction; CREST, Carotid Revascularization Endarterectomy versus Stenting Trial; NASCET, North American Symptomatic Carotid Endarterectomy Trial. Class and grade indicate the strength of the recommendation.