Clinical advisory: carotid endarterectomy for patients with asymptomatic internal carotid artery stenosis.

The investigators of the Asymptomatic Carotid Atherosclerosis Study (ACAS) are reporting the interim results of a randomized controlled clinical trial of carotid endarterectomy in patients who have asymptomatic carotid stenosis of greater than 60% reduction in diameter. In addition to aspirin and aggressive management of modifiable risk factors, one half of the patients were randomly assigned to receive surgery after angiographic confirmation of the lesion. Carotid endarterectomy is beneficial with a statistically significant absolute reduction of 5.8% in the risk of the primary end point of stroke within 5 years and a relative risk reduction of 55%. As a consequence of the trial reaching statistical significance in favor of endarterectomy, and on the recommendation of the study's data monitoring committee, physicians participating in the study were immediately notified and advised to reevaluate patients who did not receive surgery. It is important to note that the success of the operation is dependent on medical centers and surgeons who have a documented perioperative morbidity and mortality of less than 3%, careful selection of patients, and postoperative management of modifiable risk factors.