Active clinical trials for "Carotid Stenosis"

Ischemic strokes are a leading cause of death and disability worldwide. In 20% of cases they are caused by the rupture of atherosclerotic plaques in carotid arteries. Risk estimation of plaque rupture is currently suboptimal. Although pathology studies have shown that plaque composition provides a better risk assessment (lipid-rich core with thin fibrous cap = high risk (unstable plaque); fibrous core and a thick fibrous cap = low risk (stable plaque)), plaque composition cannot be determined using imaging techniques, and can therefore not be assessed non-invasively. Ultrasound, which is already widely used in clinical practice to determine plaque geometry could be an optimal technique to determine plaque composition and monitor plaques in a large population, due to its low patient burden, relatively low cost and speed of measurement. However, using conventional ultrasound it is not possible to reliably determine plaque composition. However, this might be possible using newly developed ultrasound functionalities(shear wave and strain elastography) enabling tissue stiffness estimation. It is known that recurrence risk is greatest in the first week after a stroke or transient ischemic attack (TIA) and decreases afterwards, probably due to a stabilization of the plaque due to a change in composition. Additionally, lipid-lowering medication is known to further reduce the recurrence risk after such an event, probably due to an acceleration of the stabilization process of the plaque. In this study, the investigators want to investigate whether Ultra-COMPASS ultrasound measurements (a combination of shear wave and strain elastography and ultrafast compounding (a fast variant of standard anatomical ultrasound to determine plaque geometry)) could be used to determine changes in plaque composition after a stroke / TIA. Primary objective: Investigate whether it is possible to detect plaque stabilization, determined by plaque stiffness, after a brain infarction or transient ischemic attack with Ultra-COMPASS ultrasound measurements. Secundary objectives: Determine the association between (changes in) Ultra-COMPASS measurements and the lipid-lowering drugs used 6 and 12 weeks after ischemic stroke. Determine the association between Ultra-COMPASS measurements and recurrent cardiovascular events (TIA / cerebral infarction / myocardial infarction/death) 6 and 12 weeks after ischemic stroke. Determine the association between Ultra-COMPASS measurements and (changes in) low-density lipoprotein levels 6 and 12 weeks after ischemic stroke (if known). Study design: This is a prospective, longitudinal, observational, single-center cohort study in patients after a cerebral infarction or TIA with stenosis of one / both carotid arteries of 30-70% that receive or start withcholesterol-lowering medication. Ultra-COMPASS measurements will be taken within 7 days after brain infarction/TIA and at 6 ± 1 and after 12 ± 1 weeks in both carotid arteries to see if plaques stabilize overtime and to what extent medication stimulates a beneficial change in plaque composition.

All patients undergoing carotid endarterectomy in Shaare Zedek Medical Hospital, during about 1 year, will be offered to participate. Retinal and choroidal structural changes will be assessed using swept-source OCT technology

The study aims to investigate the relationship between neuropsychological functioning and brain perfusion in patients undergoing carotid endarterectomy and control patients undergoing other peripheral vascular procedures.

Molecular analysis of the atheroma plaque. Screening for a novel biomarker of carotid status.

The correlation between metabolic syndrome and carotid artery stenosis is well established. The purpose of this study is to evaluate the relationship between morbid obesity and carotid artery stenosis.

The aim of the work is to; elucidate how the presence of carotid stenosis influence the pattern of stroke and also how it interact with other risk factors for stroke. Also identify predictors of intracranial stenosis and outcome in patients with carotid stenosis with or without intracranial stenosis.

Diabetes Mellitus (DM) is frequently appearing in patients with cardiovascular disease and these patients, as a consequence herby, has a lesser prognosis. DM is often related to increased arterial stiffness and hypertension. The investigators thesis is that DM and pre-diabetes is prevalent in patients undergoing cardiovascular surgery and to some extend is under-diagnosed. At the same time the investigators imagine that DM is closely related to the degree of arterial stiffness, and that these parameters are closely related to a new biochemical marker, fibulin-1. The investigators aim to describe the prevalence of type 2 DM and dysmetabolism in patients admitted to the hospital to undergo cardiovascular surgery and besides that to investigate if there is a connection between the degree of the dysmetabolism and arterial disease, by studying arterial stiffness and by measuring a new biochemical marker, fibulin-1, which the investigators newly have identified. The results of this project will give us a measure for the quantity of unknown DM in patients undergoing cardiovascular surgery and furthermore tell us more in terms of the connections between a newly identified plasma arterial marker, arterial stiffness and diabetes.

Atherosclerosis is the major contributor for the morbidity and mortality for the variety of cardiovascular diseases. Aortic calcification on x-ray is a marker for arterial atherosclerosis and an independent prognostic factor for the morbidity and mortality from a cardiovascular event. Carotid artery stenoses is the current accepted indication for interventional treatment of carotid artery, for the prevention of embolic event, while other arterial atherosclerosis indication, is for hemodynamic disturbance and ischemic outcome. This research will try to find whether incidental aortic calcification can predict carotid artery stenosis. Two groups will be chosen: group A - patients who had CT scan in the hospital (for different indications); Group B - patients (not from the first group) who have a significant carotid artery stenosis who are indicated for interventional treatment. The data to analyze: Group A - Patients with aortic calcification, carotid artery stenosis, and patients with both Group B - Patients who have aortic calcification Comparison of the populations within the group and among the two will show if a significant correlation between aortic calcification and carotid artery stenosis exist.

Background: Cerebral hyperperfusion syndrome (CHS) is a life threatening complication of carotid endarterectomy (CEA) and the changes of middle cerebral artery velocity are used to predict the occurrence of CHS but the accuracy is limited. In addition, changes of BP post-operatively comparing with baseline BP should be a predictive factor of CHS. Objective: The investigators aimed to create a predictive index, velocity systolic blood pressure index (VSI), for improving the predictive power of Transcranial Doppler monitoring regarding CHS. Methods: The study design is a diagnostic test, which is an observational analytic clinical study. From March 2013 to September 2014, 200 patients will be recruited. Patients will be classified according to the CHS occurrence. VSI combined the changes of middle cerebral artery velocity and blood pressure crossing CEA and the intra- and post-operative increase ratios of middle cerebral artery velocity were calculated. Their prediction power of CHS will be compared. Sensitivity, specificity, positive predictive value, negative predictive value of them will be calculated. Receiver operating characteristic analysis will be performed. Expected Outcomes: Comparing with the commonly used intra-operative and post-operative TCD monitoring, VSI may be more useful to select CHS in patients who underwent CEA. As far as the investigators know, analysis or studies combining the BP and velocity changes in the prediction of CHS have never been performed.

Microembolisation identified on diffusion-weighted magnetic resonance imaging (DW-MRI) is recognized as an important outcome measure for carotid revascularization procedures such as carotid stenting (CAS) or carotid endarterectomy (CEA). In fact, cerebral microembolisation occurring during revascularization procedures is associated with an increased risk of peri- and post-procedural stroke, transient ischemic attack as well as neurocognitive decline. Carotid artery stenting is a less invasive alternative to endarterectomy to treat symptomatic or asymptomatic carotid stenosis. Large randomized clinical trials showed a higher periprocedural risk of non-disabling stroke with CAS and a higher periprocedural risk of myocardial infarction, cranial nerve palsy, and access site hematoma with CEA. However little is known regarding the correlation between the morphological characteristics of the carotid plaque and the occurrence of microembolisation during the procedure and between microembolisation and midterm cognitive impairment. A few studies suggest that plaque morphology may be an important determinant for the increased risk of microembolisation. These studies however have mainly investigated microembolisation occurring during CAS and exploratory studies comparing the two procedures are still lacking. The purpose of the present study is to determine the correlation between the morphological characteristics of the carotid plaque and cerebral microembolisation either after carotid stenting or after carotid endarterectomy in patients with symptomatic or asymptomatic carotid disease.