View clinical trials related to Carotid Atherosclerotic Disease.
Filter by:Stroke is the first and the fourth leading cause of death in the United States and China, respectively. Disruption of cerebrovascular vulnerable atherosclerotic plaque is the major etiology of ischemic stroke. Therefore, early detection and treatment of vulnerable plaques occurring at the feeding arteries to brain (cerebral arteries) will be helpful for prevention of stroke. Atherosclerosis is a systemic disease that usually affects multiple vascular beds. Previous studies have shown that these high risk lesions in different segments of cerebral arteries (intracranial and extracranial arteries) might be racially specific. It is reported that, in stroke patients, intracranial vulnerable plaques are prevalent in Asian populations whereas atherosclerosis more frequently involves extracranial carotid arteries in American subjects. However, these findings are based on angiographic imaging approaches via measuring arterial luminal stenosis. Because the atherosclerotic plaque often appears as outward expansion, namely positive remodeling during progression, measuring luminal stenosis will underestimate the disease severity. Hence, directly viewing the plaque in the vessel wall is strongly suggested in order to objectively evaluate the cerebrovascular vulnerable plaque. High resolution, black-blood magnetic resonance (MR) imaging has been widely used to accurately characterize carotid vulnerable plaque in the last two decades. The aim of using MR black-blood techniques is to suppress the blood signal (black) to enhance the signal contrast between the vessel wall and blood in the arterial lumen. Excellent agreement has been achieved between MR imaging and histology in identification of plaque components, such as intraplaque hemorrhage and lipid core. For assessing carotid plaque, MR imaging is superior to computed tomography and ultrasound imaging techniques due to its advantages including noninvasive imaging, lack of ionizing radiation, excellent soft tissue resolution, and multi-parametric image acquisition. The Investigators hypothesize that there are specific characteristics in carotid vulnerable plaques in Chinese patients with ischemic cerebrovascular events such as ischemic stroke and transient ischemic attack (TIA). This study seeks to investigate the characteristics of vulnerable plaque in carotid arteries using high resolution, black-blood MR imaging in patients with recent TIA or ischemic stroke. This is a cross-sectional, multicenter study. A total of 1000 patients will be recruited from more than 10 different hospitals across China within 3 years. All patients will undergo MR imaging for brain and carotid arteries within two weeks after symptom onset. The prevalence of carotid vulnerable plaque and its correlations with brain ischemic lesions, traditional risk factors, and regional distribution of China will be determined.
Stroke is the second leading cause of death worldwide. One of the causes of stroke which can be treated is narrowing of the carotid artery. Currently the only definite treatment option is surgery or endovascular treatment. All patients not qualified for or awaiting surgery are, therefore, left with best medical therapy and with a yearly risk of stroke anywhere between 1% - 35% depending on the severity of the disease. The study will use the properties of a tomato extract containing lycopene. Previously studies have demonstrated beneficial properties of tomato extracts: 1. It decreases lipid oxidation 2. It decreases DNA damage 3. It has properties that reduce the speed and amount of cell divisions that inflammatory and smooth muscle cells undergo (both of these cell types contribute to atheroma formation). The investigators wish to assess whether long-term food supplementation with a tomato extract containing lycopene could influence atherosclerotic plaque characteristics. The investigators will assess this using Magnetic Resonance Imaging of the plaque and transcranial Doppler ultrasonography for counting the number of blood clots that go to the brain's arteries. Furthermore the investigators wish to examine the effect of long-term food supplementation with a tomato extract containing lycopene on blood cholesterol levels and lipid oxidation and blood markers of inflammation and injury of the inner lining of the arteries. This will be a single center, double blind, randomised, placebo controlled study.