Endarterectomy for moderate symptomatic carotid stenosis : interim results from the MRC European carotid surgery trial

Background The objective of this study was to assess whether carotid endarterectomy is an appropriate treatment for patients with recent cerebrovascular events in the territory supplied by a moderately stenosed (30-69%) internal carotid artery. Results have previously been reported for severe (70-99%) and mild (0-29%) stenosis. Methods A multicentre randomised controlled trial recruited 1599 patients with moderate stenosis treated in 97 hospitals from 15 countries, 60% of patients were allocated to receive and 40% to avoid carotid endarterectomy. The analysis was by intention to treat. Findings Nine patients were omitted from the analysis because no follow-up data were received. Stroke-free life expectancy (curtailed at 8 years) was shorter in the surgery patients than in the non-surgery control groups (patients with 30-49% stenosis, life expectancy=6.16 years [controls: 6.63 years]; patients with 50-69% stenosis, life expectancy=5.93 [6.14] years). It remains possible that patients might derive some benefit from surgery in the very long term; however, our data show that no benefit would be gained over a period of <4-5 years in patients with 50-69% stenosis and