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NCT03068442
The invesigators propose a clinical study on patients undergoing carotid surgery (endarterectomy). The invesigators will determine carotid artery imaging features associated with (1) vessel wall inflammation, (2) downstream brain inflammation, and (3) cognitive benefit from surgery. This project will uncover links between inflamed carotid plaque and downstream brain inflammation. The invesigators will also determine carotid plaque imaging features predicting cognitive benefit from carotid surgery.
NCT07004673
Carotid atherosclerotic plaque rupture is the main cause of ischemic stroke attacks, and early and precise assessment of plaque vulnerability can prevent ischemic stroke. High-resolution MRI can reflect vulnerable plaque features such as thin fibrous caps and large lipid cores, but cannot assess their metabolic information; Fibro-activated proteins (FAPs) of PET are specifically expressed in atherosclerosis and suggest vulnerable plaques by reflecting inflammation-induced fibrosis. The aim of this study was to apply 18F FDG\&68Ga-FAPI PET/MR imaging to investigate the vulnerability of carotid atherosclerotic plaques, to obtain quantitative evaluation indexes of active fibrosis within carotid plaques, and to clarify the PET/MR characteristics of unstable plaques in carotid arteries
NCT05975554
The goal of this clinical trail is to compare the differences in carotid plaque Treg cells' gene signature for activation, proliferation, and suppressive function using scRNA-seq in patients treated with IL-2 compared to control.
NCT05724836
Researchers are collecting information and blood from subjects undergoing carotid artery interventions.
NCT06933745
The P-SONAR study is a large, observational, prospective cohort study. The overall aim of the study is to investigate whether plaque burden estimation by 2D ultrasound of the carotid and femoral arteries may enhance cardiovascular risk prediction beyond NORRISK-2
NCT04063709
Stroke is a leading cause of death and disability in the United States and around the world. The goal of this work is to develop and test a noninvasive ultrasound-based imaging technology to better identify patients at high risk of stroke so that appropriate and timely intervention may be administered to prevent it.
NCT04470687
Stroke is the second leading cause of death in the Western world and the leading cause of major lifelong disability. About 15% of strokes are secondary to thrombosis or embolization of an unstable atheromatous carotid plaque. In these symptomatic patients, the degree of carotid stenosis is correlated with the risk of early recurrence. Patients with stenosis over 70% are therefore offered an endarterectomy, an operation to remove carotid plaque, to prevent future strokes\[1\]. In asymptomatic patients, the degree of stenosis is a limited predictor, and better risk stratification is required to assess the degree of plaque vulnerability and stroke risk of the patient. The therapeutic decision towards endarterectomy in addition to drug therapy is debated because of a variable and dependent benefit/risk balance for each patient. A number of imaging parameters have been studied: ulceration, heterogeneity, vascularization of the plaque for example, but their place is not well defined \[2\]. The usual evaluation of carotid stenosis is by conventional Doppler ultrasound with calculation of the degree of stenosis according to the NASCET criteria. For symptomatic stenoses the intervention is recommended when above 70% and is discussed from 50% to 70% of NASCET stenosis degree. For asymptomatic stenoses, the procedure is discussed when above 60% taking into account the patient's life expectancy, the risk of the surgery and the unstable nature of the plaque \[2\]. Destabilization of the carotid plaque is partially induced by inflammation associated with neo-vascularization. The detection of these new vessels by conventional contrast ultrasound has already shown a distinction between stable and unstable plaques, by the presence or absence of microbubbles in the plaque. However, this assessment is not very precise and only the most vascularized plaques can be detected. Ultrafast ultrasound Imaging is a new ultrasonic Imaging modality that allows detecting low speed flows, a tiny vascular structure within the vessel wall. RESEARCH HYPOTHESIS Plaques neo-vascularization would be more precisely detected and characterized by ultrafast imaging coupled with microbubble injection than conventional ultrasound imaging. A better assessment of plaque instability could improve the selection of patients for carotid endarterectomy and increase the benefit/risk ratio of this preventive surgery.
NCT06211725
Stroke is the second leading cause of death and the third leading cause of disability worldwide. The cause is usually either a blockage or a severe narrowing of a cerebral artery. An important part of stroke prevention is the diagnosis and clarification of stenosis in the arteries supplying the brain, both inside and outside the skull, in order to diagnose a high-grade stenosis at an early stage and offer the patient revascularization. In particular, asymptomatic carotid artery stenosis confronts the diagnosing physician with the question of whether revascularisation is necessary. Risk factors for stroke in asymptomatic carotid artery stenosis include contralateral TIA or cerebral infarction, male gender, rapid progression of the degree of stenosis, plaque morphology, clinically silent cerebral infarctions, Doppler sonographic evidence of microemboli or reduced vasomotor reserve. An established biomarker does not exist at this time. A candidate for such a biomarker in the blood is the protein \"neurofilament light chain\" (NFL), which is already established in the diagnosis of dementia. As a component of the cytoskeleton of neurons, it is released into the patient\'s blood when the cells are damaged and can be measured there. Another candidate is glial fibrillary acid protein (GFAP), a part of the cytoskeleton of glial cells that is also released into the blood when glial cells are damaged. A systematic investigation of the value of neurofilament light chain and the glial fibrillary acidic protein in the blood of patients with asymptomatic carotid stenosis is still lacking. VANGAS determines the value of NFL and GFAP from the blood of patients with asymptomatic carotid stenosis to determine associations with the degree of stenosis, the natural course of the stenosis (increase or decrease) and possible symptoms of the stenosis as well as the functional outcome after symptomatic stenosis.
NCT02360137
Atherosclerosis is the most common cause of stroke. The aims of the project are to compare the visual and digital analysis of sonographic images of atherosclerotic plaque in carotids in vivo, in vitro and with a histological composition of the plaque obtained from patients indicated to carotid endarterectomy, to compare the characteristics of symptomatic and asymptomatic atherosclerotic plaques and, subsequently to verify a hypothesis that ultrasound can identify the sonographic plaque characteristics associated with an increased risk of plaque progression and of ischemic stroke (unstable plaque) in patients with carotid atherosclerosis. Identifying of the sonographic characteristics of unstable plaque will allow to improve indication criteria for carotid endarterectomy or stenting and also potential changing of a drug therapy in patients with unstable plaque in the future. Cost efficiency and availability of duplex ultrasound equipment may enable to improve diagnosis of unstable plaque using this new plaque characteristics evaluation in the majority of patients with carotid plaques.
NCT04835571
In the entire world most people die from cardiovascular disease. Death is primarily from myocardial infarction (MI) and stroke which are most often caused by rupture of atherosclerotic plaques. Patients with high-grade, i.e. ≥ 70% carotid artery stenosis are at especially high risk. Magnetic Resonance Imaging (MRI) studies show that two features inside plaques that are associated with the risk of plaque rupture and subsequent cardiovascular events are: lipid rich necrotic core (LRNC) and intraplaque hemorrhage (IPH). MRI studies on carotid artery plaques typically relies on proton-density-weighted fast-spin echo, blood-suppressed T1- and T2-weighted gradient-echo sequences. The end-result is nonquantitative measures, where plaque features are identified due to their relative signal intensity. To address these problems of non-specificity, we developed a quantitative MRI (qMRI) technique based on Dixon sequences. The study intention is to enable in-depth analysis of plaque features and their relation to clinical data. For example there is an insufficient understanding of associations between lipid biomarkers and plaque contents. Our hypothesis is that we can identify quantitative changes in both plaque and lipid biomarkers after one year of optimized cardiovascular risk management (including treatment with lipid lowering drugs), and establish if there is any associations between these features. Because there is a well-established link between systemic inflammation and the presence of atherosclerotic plaques we will also study the relationship between LRNC and IPH as measured by qMRI versus circulating markers of inflammation. Method: Patients with known carotid stenosis are invited for a baseline visit and a 1-year follow up visit. The study visits include clinical assessment, blood tests, patient interview and magnetic resonance imaging of the carotid arteries. All participants are offered optimized cardiovascular risk management through the individual assessment by the study physicians.
NCT03335033
The researchers are trying to determine if the characterization of "vulnerable" carotid artery plaques can be accomplished with ultrasound-based methods that look for vessels in the plaque and measure the plaque stiffness.
NCT04679727
Carotid artery disease is a main cause of ischemic stroke and vascular dementia, and a highly prevalent disease. There is uncertainty about the optimal management of patients with serendipitously or systematically detected asymptomatic carotid artery disease, due to the paucity of information on the predictive features of serious vascular events. While percent diameter stenosis is currently the accepted standard to decide about local interventions (carotid artery stenting or endarterectomy), international guidelines also recommend the evaluation of qualitative features of carotid artery disease as a guide to treatment. There is, however, no agreement on which qualitative features are best predictors of events. Furthermore, a role for metabolic plaque profile, local mechanical and hemorheologic factors in triggering microembolization and silent ischemic events has been proposed from experimental studies. This inadequate knowledge leads to a poor ability to identify patients at higher risk and to an unwarranted dispersion of medical resources, lack of standardization in diagnostic methods, and the use of expensive and resource-consuming techniques. Against this background, the investigators aim at: 1. Prospectively identifying the best predictors of (silent and overt) ischemic stroke and vascular dementia in patients with asymptomatic subcritical carotid artery disease, by identifying the non-invasive diagnostic features of the "vulnerable carotid plaque" as a possible guide for optimal - local and systemic - treatment. 2. Transferring new ultrasound techniques possibly improving risk prediction to the clinical field 3. Assess whether "smart", low-cost diagnostic methods, such as ultrasound-based evaluations integrating established and advanced techniques, may yield at least the same level of prospective information as more expensive and less cost-effective techniques.
NCT05029661
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.
NCT05218421
Objective: To explore the association between spatio-temporal blood flow velocities (peak systole and end-diastole at prior-stenosis, at maximum stenosis, and post-stenosis) and carotid plaque vulnerability defined by histology staining. Secondary, to assess the association between ultrasound elastography and carotid plaque vulnerability defined by histology staining. Furthermore, to assess the association between blood flow-derived parameters, including wall shear stress (WSS), vector complexity and vorticity, and plaque vulnerability. To evaluate the hemodynamic consequences of a CEA. Last, to explore whether the presence of circulating biomarkers is related to the degree of plaque vulnerability (as reflected by histology and/or ultrasound). Study design: A multicentre, prospective, observational, cohort study in a total of 70 patients. Study population: Patients with a carotid artery stenosis ≥50% according to clinically performed imaging (i.e. duplex, computed tomography angiography (CTA), or magnetic resonance angiography (MRA)) that are scheduled for a CEA. Intervention (observational): A carotid ultrasound with flow and elastography (strain and shear wave) measurements will be performed maximally 2 weeks prior to the CEA. In the first 20 included patients in the Radboudumc, a 10 mL blood sample will be collected during surgery via the arterial line that is applied for regular care. The plaque excised during CEA will be histologically examined to assess the plaque composition, and therefore plaque vulnerability. Ultrasound-based flow imaging will be repeated six weeks after the CEA to assess the hemodynamic consequences of the CEA procedure. Besides, clinical parameters will be subtracted from electronic health record or, if missing, anamnestically collected from the patient. Main study parameters/endpoints: Association between 2D spatio-temporal blood flow velocities (peak systole and end-diastole at prior-stenosis, maximum stenosis and post-stenosis), measured by ultrafast ultrasound measurements, and plaque vulnerability (stable versus unstable), defined by histology staining.
NCT03985774
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.
NCT02820207
OBJECTIVE/BACKGROUND: Intraplaque neovascularization is one of the most important risk factors for unstable carotid plaque. This study was designed to evaluate whether carotid intraplaque neovascularization (IPN) can be accurately assessed by contrast enhanced ultrasound (CEUS). METHODS: Preoperative CEUS analysis of 50 carotid artery stenosis patients would be compared to histopathology performed on their plaques excised by carotid endarterectomy (CEA) with CD34 and MMP9 staining.
NCT03822195
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.
NCT03840265
As of today, no suitable multiparametric predictive method is available to properly estimate stroke risk in patients with carotid artery stenosis. Carotid artery stenosis is one of the proven risk factors of stroke incidence, but the indication of its intervention is merely the grade of stenosis itself. The current international guidelines suggest intervention for asymptomatic patients only with potentially high risk plaques but pharmacological treatment is advised to low risk patients. Unfortunately there is no proven and widely accepted system to distinguish these two categories of patients with carotid artery stenosis. In this project the following parameters will be assessed both in asymptomatic and symptomatic patients: 1, preoperative stroke risk prediction based on comparative analysis of CT angiography (CTA) results of plaque morphology and ultrasound (US) based plaque elastography analysis, 2) intracranial bloodflow will be measured by transcranial Doppler sonography(TCD), 3) presence recent of silent brain ischemia on diffusion weighted imaging (DWI) MR (magnetic resonance), 4) retinal perfusion measurement by optical coherence tomography angiography (OCT). The investigators aim to establish a clinically meaningful and more accurate (than stenosis grade) stroke risk prediction algorithm for asymptomatic carotid stenosis patients based on these parameters.
NCT02947360
Broad Goal: To demonstrate that focused vascular ultrasound (FOVUS) can accurately risk stratify patients with chest pain in the emergency department (ED). Background and Rationale: Traditional risk assessment focuses on characteristics of the pain, known Coronary Artery Disease (CAD), risk factors, electrocardiogram (ECG), and blood tests to identify active ischemia. Identifying clinically significant CAD remains one of the most challenging tasks in the ED. Current clinical decision rules err on the side of over investigation and admission. To address this limitation, the Investigators have developed a point-of-care carotid ultrasound test predictive of CAD. The Investigators have shown that carotid plaque is strongly associated with significant angiographic CAD in a population referred for angiogram. Research Aims: Primary - To determine the association between carotid plaque measured by a dedicated sonographer and 30-day major adverse cardiac events (MACE), including MI, reperfusion, or death in patients presenting to the ED with suspected cardiac ischemia. Secondary - To determine the agreement sonographer and emergency physician FOVUS results. Methodology: The Investigators propose a prospective cohort study to assess the prognostic value of a novel point-of-care carotid ultrasound plaque quantification protocol in the ED of Kingston General Hospital. We will enroll 500 consecutive patients presenting with a chief complaint of chest pain prompting at least one 12-lead ECG and troponin measurement. Patients will undergo carotid scan by a dedicated sonographer and emergency physician. Patients will be followed for MACE for 30 days. Those performing scans will be blinded to clinician's impression and care plans while clinicians will be blinded to FOVUS findings. The primary analysis will involve determination of the sensitivity, sensitivity, positive predictive value, negative predictive value and likelihood ratios associated with FOVUS for 30-day MACE. Expected Outcomes: The study will provide evidence to determine whether FOVUS may be a useful prognostic tool for emergency physicians assessing patients with suspected ischemic chest pain. The secondary analysis will provide evidence to determine whether emergency physicians can be trained to measure carotid plaque height accurately when compared to the gold standard ultrasonographer measurement. Significance: If FOVUS can reliably identify very low risk patients, implementation of this novel tool could reduce ED length of stay, monitoring, and overcrowding.
NCT03416257
In the present study, the investigators sought to prospectively examine the associations of plasma levels of TMAO (trimethylamine oxide), choline, betaine, dimethylglycine, and sarcosine with risk of incident carotid artery plaque, assessed by repeated B-mode carotid artery ultrasound imaging over a 7-year period, in women and men with and without HIV infection from the WIHS (Women Interagency HIV Study) and MACS (Multicenter Aids Cohort Study).