Active clinical trials for "Carotid Stenosis"

The purpose of this study is to determine the accuracy of a new non-invasive device, the Carotid Stenotic Scan (CSS), to check for stenosis of the internal carotid artery (ICA) as compared to a carotid ultrasound study.

Background: In a previous study, information verbally presented as relative risk (e.g. "50% less likely") or qualitative risk (e.g. "significantly less likely") resulted in many more people (66%) choosing a surgical procedure for narrowing or artery in the neck than people presented with absolute risk (e.g. "11% versus 5% over 5 years"), annualized risk (e.g. "2% versus 1% per year for 5 years") and event-free survival (e.g. "95% versus 89% over 5 years") (33%). Objectives: The purpose of this study is to determine whether the same observations are true for information that is presented visually as a bar graph. In addition, the investigators also seek to determine whether subjects feel that they understand the information better when presented visually as compared with verbally. Methods: 450 subjects will be approached in the neurology clinic as they are waiting for their office visit. If the subject agrees to participate in this 10 minute study, they will be taken to a quiet room where they will watch a 1 minute video on a laptop. The video will feature an acting physician. The presenter will be the same for all experiment groups. The presenter will describe a hypothetical medical situation in which a narrowing of one of the carotid (neck) arteries is present. The presenter will then describe the risk of a stroke related to that condition if the subject chooses medical therapy versus medical and surgical therapy. The presentation of risk will vary and may be presented in one of 3 different ways including a qualitative description, an absolute risk reduction over a fixed time period, and a relative risk reduction. These three risk groups will be presented either verbally or visually through bar graphs. In the visual subject groups, the presenter will be holding up a graph and remain silent while the graph is shown. The amount of time allotted for the graph on the video will be equal to the amount of time it takes the presenter to say the information in the auditory subject groups. Given that there will be 2 sensory modalities (verbal of visual) and 3 different presentation formats, there will be a total of 6 different videos. After the video is complete, the subject will be asked to complete a 1 page survey which will ask about the patient's age, gender, educational level, reason for the medical visit, and final decision about choice of treatment. The subjects will also answer how well they understood the data by making a mark on a 10 cm horizontal line.

The study is aimed to investigate the possible role of lectin pathway - an alternative pathway of complement activation - in affecting stability of carotid atherosclerotic plaques and the possible correlations with clinical neurologic features.

Ischaemic stroke is attributable to thromboembolism caused by carotid atherosclerotic disease in 18-25% of patients. Guidelines for prevention of stroke (especially carotid endarterectomy) in patients with carotid atherosclerotic plaque are based on the quantification of the degree of stenosis. The hyoid bone, in proximity to the carotid artery, has been implicated in the pathophysiology of carotid artery dissection, atherosclerotic carotid disease, and compressive syndromes. In atherosclerotic carotid disease, pressure on the carotid artery induced by these bone structures has been proposed to play a possible role in plaque formation and rupture, leading to stenosis, occlusion, or artery-to-artery embolism. In a recent ultrasound study, dynamic displacement of the carotid artery with interference of the hyoid bone during swallowing, named as "flip-flop" phenomenon (FFP) has been associated with carotid artery stenosis and stenosis-related stroke. Another study based on CTA assessment observed no association between hyoid-carotid distance and plaque thickness, stenosis, or progression of thickness/stenosis. In that study, in almost two-third of the patients CTA was performed for stroke/transient ischemic attack work-up, including a vast majority of patients with absence of carotid stenosis (median degree of carotid stenosis was 7%), and plaque-related stroke was not assessed. The objective of this study is to determine the anatomic hyoid-carotid interaction (ie, hyoid-carotid distance, carotid position relative to the hyoid bone, and hyoid morphology) based on CTA and its relation to the degree of carotid stenosis and stenosis-related stroke.

The trial randomise patients with asymptomatic carotid artery narrowing in whom prompt physical intervention is thought to be needed, but there there is still substantial uncertainty shared by patient and doctor about whether surgery or stenting is the more appropriate choice. The study is looking at immediate risks (within one month)and at long term benefits

To relate distribution of adipose tissue measured by a then new imaging technique, Magnetic Resonance Imaging (MRI) to extracranial carotid atherosclerosis, cardiovascular disease risk factors, and to more conventional measures of fat distribution such as body mass index (BMI) and waist/hip ratio. The primary hypothesis was that patients with extracranial carotid atherosclerosis (cases) had more intra-abdominal fat and a higher ratio of intra-abdominal fat to total or subcutaneous fat than age-sex-race matched controls.

The aim was the comparison of the perioperative time courses of matrix metalloproteinase-9 (MMP-9) and its inhibitor (TIMP-1) during elective carotid artery stenting (CAS). The investigators used a matched, historical carotid endarteriectomy group as controls. Blood samples at four time points: T1: preoperative; T2: 60 minutes after stent insertion; T3: first postoperative morning; and T4: third postoperative morning. Plasma was isolated from heparin anticoagulated blood samples by low speed centrifugation at 4 °C, and stored at -80 °C until analyzed in a single batch at the end of the study. Plasma concentrations of MMP-9 and TIMP-1 were expressed as ng/ml.

Ischaemic stroke is a major cause of death and disability worldwide. In patients with recent stroke, the 18F-fluoride positron emission tomography-computed tomography highlights high-risk culprit carotid plaque and is more discriminatory than 18F-fluorodeoxyglucose. Using hybrid positron emission tomography-magnetic resonance imaging investigators propose to build upon these findings by prospectively assessing 18F-fluoride uptake in a broad range of patients with acute transient ischaemic attack or ischaemic stroke. Investigators will specifically examine the association of 18F-fluoride uptake with multiparametric magnetic resonance imaging assessments of atherosclerotic plaque, especially the role of thrombus and lipid. Finally, using transcranial Doppler and diffusion-weighted magnetic resonance brain imaging, an assessment of the functional consequences of 18F-fluoride-positive atherosclerotic plaque will be performed. If successful, this technique has a number of valuable translational applications including the better selection of patients for carotid intervention.

The goal of this study is to evaluate the incidence of post procedure DW-MRI lesions (relative to baseline) and debris captured in the ENROUTE Transcarotid NPS inline filter during a transcarotid stenting procedure.

Classification of carotid plaque vessel wall changes in carotid stenosis accordingly to AHA classification (American Heart Association)- comparison between histology and CT. The CT is performed with a fast kVp-switching dual energy technique. To compare the ability to detect iodine contrast enhancement in the carotid plaque compared with 3T MRI with gadolinium.