Registries and Trials of Carotid Artery Stenting Versus Carotid Endarterectomy Elad I Levy, Ricardo A Hanel and L Nelson Hopkins
Stroke is the third largest cause of death after heart disease and cancer, and is the leading cause of permanent disability and disability-adjusted loss of independent life-years in Western countries. 1-3 Approximately 700 000 people in the United States experience a stroke annually, which results in an estimated $57.9 billion in direct and indirect costs. 3 By the year 2050, an estimated 1 million persons will suffer from stroke every year because of aging in the population and changes in the ethnic distribution. 4 Approximately 25% of strokes occurring annually are attributable to ischemic events related to occlusive disease of the cervical internal carotid artery (CA). 5
Randomized trials have demonstrated the benefit of carotid endarterectomy (CEA) in reducing the risk of stroke in low-risk patients with moderate to severe ( > 50%) symptomatic 6-9 or asymptomatic ( > 60%) 10-13 CA stenosis. An endovascular approach consisting of CA angioplasty with or without stent placement was initially introduced as an alternative for revascularization of carotid stenosis in patients at high risk for surgery because of concomitant medical or anatomical comorbidities. 14 Cerebral embolic protection is considered to be a major advance in the endovascular treatment of CA disease and will be discussed in depth in Chapter 18. 15,16 Currently, CA stenting with distal embolic protection is regarded as being equivalent (‘not inferior’) to CEA for high-risk patients. 17
In this chapter, the registries and trials of CA stenting versus CEA initiated before and after the availability of embolic protection devices and in patients with symptomatic and asymptomatic CA disease are reviewed, including the Asymptomatic Carotid Stenosis Stenting versus Endarterectomy Trial (ACT I), the Asymptomatic Carotid Surgery Trial-2 (ACST-2), the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the Carotid Revascularization using Endarterectomy or Stenting Systems (CaRESS) trial, the Carotid Revascularization Endarterectomy vs Stent Trial (CREST), Endarterectomy versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S), the Stenting and Angioplasty with Protec tion in Patients at High Risk for Endarterectomy (SAPPHIRE) trial, Stent-Supported Percutaneous Angioplasty of the Carotid Artery versus Endarterectomy (SPACE), the Transatlantic Asymptomatic Carotid Intervention Trial (TACIT), and the Wallstent™ trial.