Carotid artery stenting remains inferior to carotid endarterectomy for most patients.

Carotid endarterectomy (CEA) remains one of the most scrutinized surgical procedures, as a result of which there is thorough evidence for its efficacy in treating carotid artery disease. On the basis of extensive experience and clinical trials, the American Heart Association (AHA) established threshold stroke and mortality rates for carotid repair: for symptomatic patients with 50% angiographically proven stenosis, the stroke risk for repair should be less than 6%; for the asymptomatic patient with 60% angiographically proven stenosis, the stroke risk for repair should be less than 3%. When the Centers for Medicare & Medicaid Services (CMS) approved carotid stenting for the Medicare population, the approval was based upon these AHA guidelines and the plethora of clinical reports about the current state of carotid artery stenting (CAS) and CEA in the United States. The CMS approved CAS for the high-risk symptomatic patient with greater than 70% angiographic stenosis. The “high-risk” categorization has been somewhat controversial, but the CMS requested that risk stratification be determined by a surgeon credentialed to perform CEA at the treating institution. Considering that most patients who need carotid repair are Medicare eligible, most patients do not fit these high-risk criteria and are best treated by the proven standard of CEA. Four major randomized clinical trials, in separate countries, have added information to the clinical question: Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE). This German trial randomized 1,214 symptomatic patients between CAS and CEA and found stroke rates in the 2 groups to be similar.1 Specifically, the CAS patients had a 30-day stroke and death rate of 6.9% compared to the CEA rate of 6.5%. Endarterectomy versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S). This French trial randomized only 527 symptomatic patients between the 2 treatment options of CAS and CEA.2 The study concluded that CEA was superior to CAS, with a marked difference in the stroke rates of the 2 arms: CAS 9.6% versus CEA 3.4%. International Carotid Stenting Study (ICSS). This British study randomized 1,733 symptomatic patients to CAS or CEA, with 30-day stroke rates reported at 8.5% for CAS and 5.2% for CEA.3 The authors concluded that CEA was superior to CAS for treating symptomatic patients. Carotid Revascularization Endarterectomy vs Stenting Trial (CREST). This North American study randomized 2,502 symptomatic and asymptomatic patients to CEA versus CAS and found no difference in the aggregate endpoint of stroke, death, and myocardial infarction—but only when myocardial infarction was added into the endpoint.4 There were actually twice as many strokes in the CAS group (4.1%) as in the CEA group (2.3%). Commentary When considering these 2 therapies, the clinician should consider real differences in the outcomes for the patient. Many registries suggest equivalence, but these multiple, large, randomized, national studies should be carefully evaluated to understand differences. Two of the 4 national studies showed equivalence between the therapies, whereas the other 2 showed that CEA remains better. Even the 2 studies that showed equivalence (SPACE and CREST) suggest inferiority for CAS in some aspect (recurrence rate in SPACE and higher stroke rate in CREST). Only the CREST study included myocardial infarction as a primary endpoint, which suggests that CAS yields lower cardiac morbidity. How then can we differentiate between these therapies? Fundamentally, the two are different: CAS opens a stenosis and traps the embolic debris behind a metal scaffold across the carotid bifurcation; CEA removes the embolic source. During treatment procedures, CAS carries a higher embolic risk, which confers a higher stroke risk and a greater incidence of postprocedural cognitive decline for our patients. Longevity of repair should also be considered. The restenosis rate is probably lower for CEA because of this fundamental difference in the treatment mechanism, but only the ICSS and SPACE studies confirmed that supposition. With more time, this answer may be confirmed through further data maturation from these studies. With continued modification of CAS, its stroke risk has begun to approach the stroke risk of CEA, to the extent that CAS might present an improved risk profile for some high-risk patients, particularly for patients with hostile neck anatomy. In general, there are also high-risk anatomic features for CAS (heavy calcifications, diseased aortic arch, tortuous arteries, etc.) as there are for CEA (irradiated neck, reoperative surgery, laryngeal nerve palsy, etc.). In addition, although our patients do not currently have input regarding the cost of a therapy, we should consider the cost factor when evaluating treatment options. The additional disposable items and the stents used for CAS increase its procedural costs by 40% to 50% over those of CEA.5,6 If value-added medicine becomes more of a reality, it will be difficult to justify a more expensive therapy that offers equivalent or worse outcomes than the current therapy. Although CAS probably has an important role, it is not best suited for most patients with carotid artery stenosis. In some recent reports, there is near equivalence between CAS and CEA in a selected group of patients, and CAS might be better in a small subset of patients. However, CEA has stood the rigorous test of time, has maintained superiority in most clinical trials, and remains the best treatment for most patients who require repair of carotid artery stenosis.