Severe stenosis of the carotid artery (60–90%) has been associated with an increased long-term risk of ischaemic stroke. Although carotid endarterectomy can remove the narrowing, the procedure itself is associated with a significant risk of stroke or death.
The ACST-1 (asymptomatic carotid stenosis) trial randomised 3120 patients to carotid endarterectomy (CEA) or to indefinite deferral of any carotid procedure, and were followed up until death or for a median period amongst survivors of 9 years. The primary outcomes were death and stroke within 30 days, and non-perioperative stroke.
In those undergoing surgery, the perioperative risk of stroke or death within 30 days was 3.0%. Excluding perioperative events and non-stroke mortality, the stroke risk was 4.1% in the CEA group versus 10.0% in the deferred group at 5 years. Combining perioperative events and strokes, net risks were 6.9% versus 10.9% at 5 years, and 13.4% versus 17.9% at 10 years. Net benefits were seen for both men and women up to 75 years of age at entry, although not for older patients.
10-year stroke risk is reduced by successful CEA for severe carotid stenosis in patients younger than 75 years of age.
▶ Halliday A, Harrison M, Hayter E, et al. 10-Year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): a multicentre randomised trial. Lancet2010;376:1074–84.