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Ischemic Stroke—Stenting versus Surgery for Carotid Disease


between CAS and CEA (7.2 versus 6.8 %, HR 1.11, 95 % CI 0.81–1.51, p<0.51) during long-term follow-up (median 2.5 years). An interaction with age and treatment was detected (p<0.02). Outcomes were slightly better after CAS for patients aged <70 years and better after CEA for patients aged >70 years. The proportion of patients developing stroke within 30 days of the procedure was significantly higher in the CAS than the CEA group (4.1 versus 2.3 %, HR 1.8, 95 % CI 1.1–2.8); on the other hand, the frequency of MI within 30 days of the procedure was significantly lower in the CAS group (1.1 versus 2.3 %, HR 0.5, 95 % CI 0.3–0.9). However, at one-year follow-up the quality of life was significantly diminished for patients who developed stroke compared with those with MI.31


For the subgroup of patients with symptomatic carotid disease, the peri-procedural rate of stroke and death was significantly higher for those assigned to stenting compared with endarterectomy (6.0 versus 3.2 %, HR 1.89, 95 % CI 1.1–3.2).32


In addition, CREST found that the


difference in peri-procedural complications between CEA and CAS was accentuated in women. Peri-procedural events occurred in 35 (4.3 %) of 807 men assigned to carotid artery stenting compared with 40 (4.9 %) of 823 assigned to CEA (HR 0.90, 95 % CI 0.57–1.41) and 31 (6.8 %) of 455 women assigned to carotid artery stenting compared with 16 (3.8 %) of 417 assigned to CEA (HR 1.84, 95 % CI 1.01–3.37, interaction p=0.064).33


Asymptomatic Carotid Stenosis


Whether to recommend revascularization for an asymptomatic carotid stenosis is a question that has persistently troubled neurologists, due to the fact that prior studies have found variable benefit from revascularization, based upon a number of different patient characteristics. In addition, advances in medical therapies have raised doubts on whether the original CEA studies would show similar results if they were performed now.


Carotid Endarterectomy in Asymptomatic Carotid Stenosis


The Asymptomatic carotid atherosclerosis study (ACAS) was a prospective randomized multicenter trial that randomized 1,662 patients with asymptomatic carotid stenosis of >60 % to CEA and medical management.8


After a median follow-up of 2.7 years, the


aggregate five-year risk of ipsilateral stroke, any peri-operative stroke, or death was estimated to be 5 versus 11 % for an RR reduction of 0.53 (95 % CI 0.22–0.72) favoring CEA. However, for surgery to be beneficial, the rate of peri-operative death and other serious complications had to be less than 3 %, and the expected patient survival had to be at least five years. The study showed higher incidence of peri-operative complications in women compared with men (3.6 versus 1.7 %), and men had an ARR of 8 % compared with 1.4 % in women, with women receiving no statistically significant benefit from revascularization.


The Asymptomatic carotid surgery trial (ACST) was a subsequent randomized multicenter trial that enrolled 3,120 patients with ≥60 % asymptomatic carotid stenosis but no recent neurological symptoms (stroke or TIA) between immediate intervention (CEA) or indefinitely deferred CEA (until there was an associated stroke or TIA). Of 1,560 patients allocated to immediate treatment, half had CEA by one month and 88 % by one year, and of the deferred group only 4 % per year underwent CEA.9


The CEA group had a peri-operative risk of stroke or US NEUROLOGY


Table 2: Asymptomatic Carotid Disease—What Do the Guidelines Recommend?


Asymptomatic Carotid Artery Stenosis 1. Patients with asymptomatic carotid artery stenosis


Level of Evidence (Class I; level of


should be screened for other treatable risk factors for evidence C) stroke with institution of appropriate lifestyle changes and medical therapy


2. Selection of asymptomatic patients for carotid revascularization should be guided by an assessment of


comorbid conditions and life expectancy, as well as other individual factors, and should include a thorough discussion of the risks and benefits of the procedure with an understanding of patient preferences


3. The use of aspirin in conjunction with CEA is (Class I; level of


recommended, unless contraindicated, because aspirin evidence C) was used in all of the cited trials of CEA as an antiplatelet drug


4. Prophylactic CEA performed with <3 % morbidity and (Class IIa; level of mortality can be useful in highly selected patients with evidence A) an asymptomatic carotid stenosis (minimum 60 % by angiography, 70 % by validated Doppler ultrasound). It should be noted that the benefit of surgery may now be lower than anticipated based on randomized trial results, and the cited 3 % threshold for complication rates may be high because of interim advances in medical therapy


5. Prophylactic carotid artery stenting might be considered in highly selected patients with an asymptomatic carotid


stenosis (>60 % on angiography, >70 % on validated Doppler ultrasonography, or >80 % on computed tomographic angiography or MRA if the stenosis on ultrasonography was 50–69 %). The advantage of revascularization over current medical therapy alone is not well established 6. The usefulness of CAS as an alternative to CEA in asymptomatic patients at high risk for the surgical procedure is uncertain


7. Population screening for asymptomatic carotid artery stenosis is not recommended


(Class IIb; level of evidence B)


(Class I; level of evidence C)


(Class IIb; level of evidence C)


(Class III; level of evidence B)


The revised American Heart Association/American Stroke Association (AHA/ASA) guidelines published in 2011 for the primary prevention of stroke make the above recommendations for the management of asymptomatic carotid disease. CAS = carotid angioplasty and stenting; CEA = carotid endarterectomy; MRA = magnetic resonance angiography. Source: Goldstein et al., 2011.42


death of 3.1 % within 30 days of surgery; however, the net five-year risk for all strokes or peri-operative death in the immediate CEA group was reduced by nearly half compared with the CEA deferral group (6.4 versus 11.8 %, 95 % CI 2.96–7.75), results that are similar to the ACAS study.


The ARR for preventing non-peri-operative stroke over five years was greater for men than for women (8.2 %, 95 % CI 5.64–10.78, versus 4.08 %, 95 % CI 0.74-7.41), although the benefit was statistically significant for both. CEA was shown to benefit patients <75 years of age, but there was no statistical benefit in patients who were older. ACST re-emphasized that, when selecting asymptomatic patients for carotid revascularization, age, sex, life expectancy and the cited 3 % complication rate must all be taken into account. Finally, it is important to note that patients randomized to medical therapy in both ACAS and ACST were undertreated in terms of modern interventions such as statins and aggressive blood pressure goals.


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