The Characteristics Of Carotid Artery Disease And Relationship Between It And Outcome Of Ischemic Stroke

Background and objective: Carotid artery disease in ischemic stroke was common, but the relationship between carotid artery disease and outcome of ischemic stroke remained uncertain. The present study was designed to observe the incidence of stenosis of extracranial arteries, the property of carotid plaque and the common carotid intima-media thickness (CCA-IMT),analysis the characteristics of carotid artery disease among various ischemic stroke subtype, and explore the relationship between carotid artery disease and outcome of ischemic stroke, which provide clinical evidence for individualized treatment of stroke in order to more directionally secondary prevention.Materials and methods: From Jan.1, 2005 to Dec.31, 2006, the consecutive cases of stroke in the neurological wards of the West China Hospital, Sichuan University were prospectively registered. The self-care patients who was the first onset of stroke or used to have a stroke within 7 days were checked by Color-coded duplex ultrosongraphy, which is all included in the study. The common carotid intima-media thickness (CCA-IMT), the degree of stenosis and carotid atherosclerotic plaque were rec orded. All included patients were classified in ischemic stroke subtypes based on OCSP criteria. We collected the other clinical data associated with the prognosis of stroke and then followed up the outcome at the end of 3rd, 6th and 12th month after the onset of ischemic stroke. The outcome was death, disability and stroke recurrence. We investigated therelationship between carotid artery disease and outcome by multivariatelogistic regression.Results: 854 patients of ischemic stroke were registered in two years. 675 patients were checked by color-coded duplex ultrosonography. The proportion of ischemic stroke subtype according to OCSP criteria was as follows: partial anterior circulation infarcts (32.7%), total anterior circulation infarcts (22.0%), posterior circulation infarcts (18.2%), lacunar infarcts(26.1%). 215 patients with extracranial arteries stenosis included 93 patients (13.8%) with carotid artery stenosis(≥50%) included occlusion, and there was 33 patients (4.9%) with carotid artery stenosis(70%～99%) and 11 patients with occlusion. 515 carotid plaques were found in 386 patients(57.2%), composed of 263 unstable plaque(51.0%). Carotid plaque was commonly seen most in the bifurcatus area of carotid artery (317/515, 61.5%). The range of CCA-IMT was 0.5-3.8mm, and the mean level of CCA-IMT is 1.00±0.36mm, 1.02±0.34mm at male and 0.95±0.33mm at female. Among OCSP stroke subtypes the (50%-69%) carotid stenosis is most common in PACI (14.5%), the≥70% carotid stenosis is most common in TACI (22.6%). Unstable plaque and high level of IMT were common in TACI. Carotid artery stenosis (P<0.05). carotid plaque and CCA-IMT were the independent influencing factors of recurrence of ischemic stroke at 3 months. The OR of recurrence associated with influencing factors was 3.566(95%CI, 2.015-6.439) with carotid artery stenosis (≥50%), 3.140 (95%CI, 1.588-7.621) with unstable carotid plaque and 2.802 (95%CI, 1.192-6.590) with CCA-MT. The independent predictors of death/dependency at 3 months were carotid artery stenosis and carotid plaque. The odds ratio (OR) of death/dependency at 3 months associated with independent predictors was 3.365 (95%CI, 1.800-6.29.) with carotid artery stenosis (≥50%) and 1.847 (95%CI, 1.112-6.293) with unstable carotid plaque.Conclusion: 1. There are 215 patients (31.9%) with extracranial arteries stenosis included 93 patients (13.8%) with carotid artery stenosis (≥50%), 386 patients (57.2%) with carotid plaques who more half with unstable plaque, and 274 patients (40.5%) whose CCA-IMT is > 1.0mm in 675 patients with ischemic stroke.2. The≥70% carotid stenosis is most common in PACI (22.6%); the (50%-69%) carotid stenosis, unstable plaque and high level of MT were common in TACI. 3. Carotid stenosis (≥50%), unstable plaque and IMT are the independence influencing factors of outcome of stroke. 4. The further study will be warranted to assess the necessity of therapy for carotid artery stenosis artery, unstable plaque and IMT.