Background:
Extracranial vertebral artery disease is seen in patients with internal carotid artery stenosis although the clinical significance not well understood.
Methods:
We analyzed data that was collected as part of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) trial which recruited patients with recently symptomatic internal carotid artery stenosis. We used Cox proportional hazards analysis to compare the relative risk of various endpoints between the three categories of extracranial vertebral artery disease (normal/hypoplastic, moderate/severe stenosis, and occlusion). The multivariate analyses were adjusted for age, gender, basic demographics and severity of carotid stenosis.
Results:
Of the 1181 subjects who had extracranial vertebral artery ultrasound evaluation, moderate to severe stenosis and occlusion of one of both extracranial vertebral arteries was diagnosed in 152(12.9%) and 57(4.8%) subjects, respectively. During the mean follow up period (±SD) of 22.1±7.1 months 102(8.6%) and 60(5.1%) experienced a stroke or died, respectively. Compared with subjects with normal or hypoplastic vertebral artery, there was a non-significant 30% higher risk of any stroke among subjects with moderate to severe vertebral artery stenosis (relative risk [RR]1.3, 95% confidence interval [CI]0.7-2.3) after adjusting for potential confounders. There was a 40% and 50% higher risk of ipsilateral stroke (RR 1.4, 95% CI0.7-2.5) and death (RR 1.5, 95% CI 0.7-3.1) among subjects with moderate to severe vertebral artery stenosis after adjusting for potential confounders. In Kaplan Meir analysis, the estimated 1 and 2 year stroke free survival for subjects with moderate to severe vertebral artery stenosis was 88% (standard error [SE]2.6%). In comparison, the estimated 1 and 2 year stroke free survival for subjects with normal or hypoplastic vertebral artery was 92.5%(SE0.8%)and 91.6%(SE0.9), respectively.
Conclusions:
There appears to be an increased risk of stroke and death in patients with symptomatic internal carotid artery stenosis with concurrent asymptomatic extracranial vertebral artery stenosis.
Endovascular treatment of extracranial vertebral artery stenosis