Natural History of > 60% Asymptomatic Carotid Stenosis in Patients With Contralateral Carotid Occlusion

Carotid endarterectomy was reported to be beneficial for patients with asymptomatic carotid stenosis of 60% or greater at the conclusion of the Asymptomatic Carotid Atherosclerosis Study, but other studies report mixed results. In a prospective study of contralateral carotid occlusion, the authors analyzed the natural history of asymptomatic carotid stenosis in patients with of 60% or greater stenosis. Over a 1 0-year period, 82 patients were examined both clinically and with duplex surveillance every 6 months and received maximum medical therapy. If lesions progressed to 70% or greater or became symptomatic then carotid endarterectomy was considered. Mean follow-up was 59.5 months (7 to 141 months). A 60% rate of combined neurologic events of transient ischemic attack and stroke was noted: in 27 patients (33%) late strokes occurred; 8 were contralateral and 19 were ipsilateral, and 22 patients had late transient ischemic attacks (15 contralateral, 7 ipsilateral). Late carotid endarterectomy was performed in 21 patients. A Kaplan-Meier analysis showed that freedom from ipsilateral stroke at 5 years was 73%, but the study results showed the rate at 5 years to be 63%. The authors concluded that the incidence of ipsilateral strokes and all strokes in patients with asymptomatic carotid stenosis of between 60% and 70% and with contralateral carotid occlusion is higher than was has been reported in other studies and that they may benefit from prophylactic carotid endarterectomy.