Carotid endarterectomy and prevention of cerebral ischemia in symptomatic carotid stenosis. Veterans Affairs Cooperative Studies Program 309 Trialist Group

Abstract

Objective: To determine whether carotid endarterectomy provides protection against subsequent cerebral ischemia in men with ischemic symptoms in the distribution of significant (greater than 50%) ipsilateral internal carotid artery stenosis.

Design: Prospective, randomized, multicenter trial.

Setting: Sixteen university-affiliated Veterans Affairs medical centers.

Patients: Men who presented within 120 days of onset of symptoms that were consistent with transient ischemic attacks, transient monocular blindness, or recent small completed strokes between July 1988 and February 1991. Among 5000 patients screened, 189 individuals were randomized with angiographic internal carotid artery stenosis greater than 50% ipsilateral to the presenting symptoms. Forty-eight eligible patients who refused entry were followed up outside of the trial.

Outcome measures: Cerebral infarction or crescendo transient ischemic attacks in the vascular distribution of the original symptoms or death within 30 days of randomization.

Intervention: Carotid endarterectomy plus the best medical care (n = 91) vs the best medical care alone (n = 98).

Results: At a mean follow-up of 11.9 months, there was a significant reduction in stroke or crescendo transient ischemic attacks in patients who received carotid endarterectomy (7.7%) compared with nonsurgical patients (19.4%), or an absolute risk reduction of 11.7% (P = .011). The benefit of surgery was more profound in patients with internal carotid artery stenosis greater than 70% (absolute risk reduction, 17.7%; P = .004). The benefit of surgery was apparent within 2 months after randomization, and only one stroke was noted in the surgical group beyond the 30-day perioperative period.

Conclusions: For a selected cohort of men with symptoms of cerebral or retinal ischemia in the distribution of a high-grade internal carotid artery stenosis, carotid endarterectomy can effectively reduce the risk of subsequent ipsilateral cerebral ischemia. The risk of cerebral ischemia in this subgroup of patients is considerably higher than previously estimated.