First phase report of cooperative Veterans Administration asymptomatic carotid stenosis study--operative morbidity...

Ten Veterans Administration medical centers representing all regions of the country participated in a cooperative study to evaluate the etiologic importance of asymptomatic carotid disease in the development of transient ischemic attack and stroke. The study prospectively randomized patients between carotid endarterectomy and nonoperative treatment with both groups receiving 1300 mg aspirin daily. All patients considered for the study had carotid angiography. Inclusion in the study required at least a 50% diameter reduction of the internal carotid artery. Four hundred forty-four patients were randomized between nonoperative (233 patients) and operative groups (211 patients). In the operative group 195 had unilateral carotid endarterectomies, and eight patients had staged bilateral procedures, for a total of 211 carotid operations. Thirty-day mortality was 1.9% (4/211); all resulting from cardiac causes. One patient who died also had a neurologic deficit. The incidence of stroke was 2.4% (5/211), and the combined stroke and mortality rate was 4.3%. Transient ischemic events occurred in two patients (0.9%). Coronary artery disease is the prime determinant of operative mortality and justifies rigorous preoperative cardiac evaluation to identify those patients at risk. This multicenter prospective clinical trial demonstrates that carotid endarterectomy can be safely performed and provides a valid standard with which to compare the nonoperative cohort.