Asymptomatic Extracranial Vertebral Artery Disease in Patients with Internal Carotid Artery Stenosis.

BACKGROUND: Extracranial vertebral artery disease is seen in patients with internal carotid artery stenosis, although the clinical significance is not well understood. OBJECTIVE: To determine the prevalence and natural history of extracranial vertebral artery disease in patients with recently symptomatic internal carotid artery stenosis. METHODS: We analyzed data collected for patients with recently symptomatic internal carotid artery stenosis in the Stent-Protected Angioplasty vs Carotid Endarterectomy trial. We used Cox proportional hazards analysis to compare the relative risk of various endpoints (any stroke, ipsilateral stroke, and death) between the 3 categories of extracranial vertebral artery disease (normal/hypoplastic, moderate/severe stenosis, occlusion) adjusting for age, gender, severity of internal carotid artery stenosis at baseline (<70% and ≥70%), allocated procedure (carotid angioplasty and stent placement or carotid endarterectomy) and hypertension. RESULTS: Moderate to severe stenosis and occlusion of 1 of both extracranial vertebral arteries were diagnosed in 152 (12.9%) and 57 (4.8%) of 1181 subjects, respectively. Comparing subjects with normal or hypoplastic vertebral artery, there was nonsignificant 30%, 40%, and 50% higher risk of any stroke (hazard ratio [HR] 1.3, 95% confidence interval [CI] 0.7-2.3), ipsilateral stroke (HR 1.4, 95% CI 0.7-2.5), and death (HR 1.5, 95% CI 0.7-3.1) among subjects with moderate to severe vertebral artery stenosis after adjusting for potential confounders. CONCLUSIONS: There may be an increased risk of stroke and death in patients with symptomatic internal carotid artery stenosis with concurrent asymptomatic extracranial vertebral artery stenosis.

Ex vivo characterization of carotid plaques by intravascular ultrasonography and virtual histology: concordance with real plaque pathomorphology.

BACKGROUND: The purpose of this study was to evaluate the accuracy of carotid plaque characterisation by virtual histology using intravascular ultrasonography (VH-IVUS) by comparing the results with real morphology. METHODS: Following elective carotid endarterectomy (CEA), atherosclerotic plaques from 36 patients (19 asymptomatic, 17 symptomatic) underwent ex-vivo VH-IVUS examination. Afterwards, tissue specimens were fixed with formalin and embedded in paraffin. Atherosclerotic lesions were characterised following hematoxylin/eosin (HE) and Elastin van Gieson (EvG) staining using AHA classification (stages I to VIII). The plaque composition, cellularity, severity of inflammation, and atheroma-associated macrophages and foam cells were compared with virtual histology. RESULTS: Patients with symptomatic carotid artery stenosis showed most commonly lesion type IV-V (N.=9; 52.9%), followed by type VI (N.=3; 17.6%) and type VII (N.=3, 17.6%), type VIII (N.=1; 5.9%) and type I-III (N.=1; 5.9%). In asymptomatic patients with the main lesion was type VII (N.=8; 42.1%), followed by type I-III (N.=4; 21.1%), type IV-V (N.=3, 15.8%) and type VIII (N.=1; 5.3%). The composition of unstable lesions differed significantly in symptomatic patients compared to asymptomatic subjects (70.1% vs. 31.6%, P=0.03). The concordance between the histological results and the VH-IVUS classification was 86.1% (Cohen`s kappa of 0.72). CONCLUSIONS: In the present study, our findings demonstrated significant correlation between true plaque composition determined by histology and VH-IVUS. Thus, IVUS might be useful as an additional diagnostic method to detect patients with unstable rupture-prone plaques.