Carotid artery surgery and stenting have similar long-term effects on stroke: Lancet

A total of 3,625 patients were enrolled from 130 centres in 33 countries. Participants were randomly allocated 1:1 to CAS or CEA and followed up for an average of five years. The main outcomes were: 1) procedural risks (morbidity and mortality within one month after the procedure); and, most importantly, 2) non-procedural stroke, subdivided by severity.

Regarding procedural risks, 1% of patients in both groups had a disabling stroke or died within 30 days (15 allocated to CAS and 18 to CEA) and 2% had a non-disabling procedural stroke (48 allocated to CAS and 29 to CEA).

The main outcome was five-year non-procedural stroke; fatal or disabling stroke occurred in 2.5% of patients in each group, for a rate ratio (RR) of CAS versus CEA of 0.98 (95% confidence interval [CI] 0.64–1.48; p=0.91), and any non-procedural stroke occurred in 5.3% of the CAS group versus 4.5% of the CEA group (RR 1.16; 95% CI 0.86–1.57; p=0.33). A meta-analysis of this and all other major trials of CAS versus CEA yielded a similarly non-significant result for any stroke (RR 1.11; 95% CI 0.91–1.32; p=0.21).

Principal investigator Professor Alison Halliday of the University of Oxford, UK said: "We have shown that, for patients with a severely narrowed carotid artery, stenting and surgery have similar effects on the chances of having a disabling or fatal stroke. The risk from each procedure is about 1%. After that, however, the annual risk over the next five or more years is halved, from 1% down to 0.5% per year."