Footnotes

• Competing interests None.

• Provenance and Peer review Not commissioned; not externally peer reviewed.

• Addendum The ICSS trial reported its 30-day findings on 28 May 2009, concluding that CEA was statistically superior to CAS. The trial recruited 1700 recently symptomatic patients from 50 centres in 15 countries and on an “intention-to-treat” analysis, the 30-day risk of death/stroke was 5.1% after CEA compared with 8.5% after CAS (p = 0.004). On a “per protocol” analysis, the respective figures were 4.0% after CEA versus 7.4% after CAS (p = 0.003). These results do not mean that CAS should be abandoned, but there is clearly uncertainty about its optimal role. It is expected that the data from ICSS, EVA-3S and SPACE will be combined in order to identify subgroups (possibly younger patients) in whom CAS is preferable.