Abstract 100: Extracranial Vertebral Artery Atherosclerotic Disease in Patients With Symptomatic Stenosis of the Internal Carotid Artery. The North American Symptomatic Carotid Endarterectomy Trial

Background and Purpose: The prevalence of atherosclerotic disease of extracranial vertebral artery and associated long-term outcomes in patients with stenosis of the internal carotid artery (ICA) are not well defined. Methods: We ascertained the rates of any stroke, vertebrobasilar stroke, and all-cause mortality over 5 years associated with various categories of extracranial vertebral artery disease based on angiographic severity (<30%, 30-69%, 70-99%, and occlusion) in patients with symptomatic ICA stenosis who participated in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). We also studied the relative benefit of carotid endarterectomy in reduction of ipsilateral stroke in patients with various categories of extracranial vertebral artery disease after adjusting for age, gender, and severity of ICA stenosis. Results: Among the 798 patients who underwent angiographic catheterization of extracranial vertebral artery, the severity of stenosis was categorized as <30% (n=342), 30-69% (n=...