Medical compared with surgical treatment of asymptomatic carotid artery stenosis.

The Asymptomatic Carotid Atherosclerosis Study (ACAS) results suggest that carotid endarterectomy combined with aspirin and risk factor reduction is superior to aspirin and risk factor reduction is superior to aspirin and risk factor reduction alone in preventing ipsilateral stroke in asymptomatic patients with diameter stenosis of the carotid artery of 60% or more. The absolute risk reduction over 5 years conferred by surgical therapy is modest (5.9%) compared with the risk reduction conferred by surgical therapy for symptomatic carotid disease but compares favorably with the degree of stroke prevention shown for antihypertensive therapy in the elderly. For prevention of stroke in women and for prevention of major stroke, the ACAS results favoring surgery did not reach statistical significance. The combined arteriographic and perioperative surgery-related mortality and stroke rates achieved by the carefully selected surgical teams was low (2.3%). Accordingly, carotid endarterectomy can be recommended for preventing stroke in the setting of hemodynamically significant stenosis when the arteriographic and surgical complication rates can be kept low.