Why the definition of high risk has been inappropriately used in previous carotid trials.

Carotid artery revascularization by endarterectomy is an effective means of stroke prevention in selected patients with carotid stenosis. With the development of endovascular techniques, carotid artery stenting (CAS) has been proposed as a viable alternative to carotid endarterectomy (CEA), particularly in patients considered at high risk for CEA. Guidelines have established criteria that outline these patients who are considered at "high risk" for complications after CEA, to whom CAS may provide benefit. The validity of these theoretical high-risk criteria, however, is yet unproven, and, as a consequence, there is no clear evidence suggesting that the risk with CAS is lower in these high-risk patients compared with CEA. This manuscript summarizes the role of "high risk" within recent trials and discusses why the optimal treatment for these patients with deemed high risk for surgery remains a matter of debate.