When Will We Have What We Need to Advise Patients How to Manage Their Carotid Stenosis?: Lessons From SPACE-2

Abstract

The recently published SPACE-2 trial (Stent-Supported Percutaneous Angioplasty of the Carotid Artery Versus Endarterectomy-2) compared 3 treatments to prevent stroke in patients with asymptomatic carotid stenosis ≥70%: (1) carotid endarterectomy plus best medical treatment (BMT), (2) transfemoral carotid artery stenting plus BMT, or (3) BMT alone. Because of low enrollment, the findings of similar safety and efficacy for carotid endarterectomy, carotid artery stenting, or BMT alone were inconclusive. Publication of the CREST (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial)-2 results should provide level A evidence that has been lacking for 2 to 3 decades, to guide treatment of asymptomatic patients with severe carotid stenosis. For symptomatic patients with ≥70% stenosis, no trials are underway to update the degree of benefit reported for carotid endarterectomy by NASCET (North American Carotid Endarterectomy Trial) and ECST (European Carotid Surgery Trial), published in 1991. Subsequently, the use of cigarettes has plummeted, and major improvements in medical treatments and in carotid revascularization have emerged. These advances have coincided with abrupt decline in the clinical end points necessary for treatment comparisons in procedural trials. One of the advances in the invasive management of carotid disease has been transcarotid artery revascularization, already with limited approval by the US Food and Drug Administration. Establishing safety and efficacy of transcarotid artery revascularization compared with carotid endarterectomy, carotid artery stenting, or BMT alone may be challenging because of enrollment, regulatory, and funding barriers to design and complete an adequately powered randomized trial.

Keywords: carotid stenosis; constriction; endarterectomy; medical treatment; stents.

Figure 1:

The graphs are in a graph-within-a-graph format, with the larger graph showing a horizontal axis extending to 100% and the smaller graph showing the horizontal axis extending to 15%. The horizontal extent of the bars represents periprocedural stroke and death plus postprocedural ipsilateral stroke at 5 years, except for CREST which was at 4 years. The numerical percentages shown in the light blue bars represent periprocedural stroke and death, and the percentages in the dark blue bars represent postprocedural ipsilateral stroke and death, except for ACST and ACST-2 which show the percentage of any stroke.