[Prevention of cerebral ictus, of carotid origin]

The current incidence of stroke in Europe and the USA is about 200 per 100,000 population per annum. Eighty percent of strokes are ischaemic and 20% are due to hemorrhage. Approximately half the patients with ischaemic strike have carotid artery stenosis and about one third (10% all stroke victims) have had no warning symptoms such as transient ischaemi attacks. The European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) have effectively shown that carotid endarterectomy (CEA) can prevent strokes in symptomatic patients. The benefit of operation is, at present, confined to those with at least 70% stenosis; for 30-69%, the trials have not yet reported a result. In asymptomatic patients the Veterans Administration Study and the Asymptomatic Carotid Atherosclerosis Study (ACAS) have yielded promising results that surgery may reduce the risk of TIA and minor stroke. There is as yet no convincing evidence in asymptomatic patients that moderate or severe stroke (or death) can be prevented by CEA. The aim of this trial is to determine whether CEA and appropriate best medical treatment (BMT) can improve stroke free survival time when compared with BMT alone.