Active clinical trials for "Constriction, Pathologic"

Rationale: Approximately 15-20% of strokes originates from an atherosclerotic plaque rupture in the carotid artery. To reduce the risk of stroke, patients should be evaluated for possible carotid endarterectomy (CEA), which is based on simple geometrical and clinical measures. Multiple studies have shown that the current risk stratification may lead to both over- and under-treatment for patients with carotid artery stenosis. This implicates that the current guidelines are lacking patient-specific parameters and have limited sensitivity. There is a wealth of evidence implicating the important role of local (disturbed) blood flow throughout the onset and progression of atherosclerosis. Novel flow-related measures, that go beyond simple geometrical indications, are required to improve diagnosis and treatment in patients with carotid artery stenosis. Nowadays, ultrasound (US) is one of the main techniques to assess for the presence and extent of carotid artery stenosis. However, current clinically-used US systems are unable to acquire and visualize the complex flow phenomena that play such a crucial role in the atherosclerotic disease process. With the advent of ultrafast ultrasound imaging, acquiring thousands of images per second, continuous tracking of flow in all directions became feasible, which enables us to image two-dimensional blood flow and possible disturbances with high accuracy and precision. In this project, we aim to assess whether flow (related) parameters are associated with disease progression (and if so, which), in order to map the progression of atherosclerotic plaques using non-invasive, US-based blood flow imaging. In the future, this could improve risk stratification for individual patients for surgery, decrease patient mortality and morbidity, and therefore reduce healthcare costs. Objective: To longitudinally assess the association between spatio-temporal blood flow velocities (peak systole and end-diastole at common carotid artery, maximum stenosis and internal carotid artery) and the progression of carotid atherosclerosis defined by duplex measurements. Secondary objectives are to investigate the association between blood flow-derived parameters, including wall shear stress (WSS), vector complexity and vorticity, and the progression of atherosclerosis defined by duplex measurements. Furthermore, to assess the association between spatio-temporal blood flow velocities and blood flow-derived parameters (WSS, vector complexity and vorticity) and the progression of atherosclerosis as measured using ultrasound-based strain imaging.

The investigators are developing a new test of pedestrian hazard detection in virtual reality (VR) head-mounted display (HMD) headset, which shows virtual oncoming pedestrians in 3D while subjects are walking in real-world environment, for evaluation of visual field expansion to improve mobility in people with visual field loss.

Prospective, randomised, open-label, international multicenter trial to evaluate the safety and efficacy of drug-coated balloon (DCB) treatment compared to drug-eluting stenting (DES) in patients with large coronary artery disease.

TASS-2 (Tyrolean Aortic Stenosis Study-2) aims to characterize the clinical value of minimally elevated troponin T plasma levels both in patients with asymptomatic and symtomatic aortic stenosis.

The purpose of the research is to understand structural plaque abnormalities that make a carotid plaque unstable and brake off (embolize) which would help to predict and treat individuals who are likely to suffer not only classic episodic major strokes but also cognitive impairment.

Background: The prevalence of both senile cardiac amyloidosis (CA) and aortic stenosis (AS) markedly increases with age. Aortic stenosis increases left ventricular pressure overload. Cardiac deposits have been observed in AS and the amount of these deposits has been correlated to post-surgical outcome. As they are strong echocardiographic and cardiac MRI imaging similarities between CA and AS, the investigators hypothesized that the deposit observed in AS is transthyretin amyloid deposit. The investigators objective is to demonstrate that amyloid deposit is associated with poor outcomes following aortic stenosis surgical valve replacement. Materiel and methods: 180 patients with indication for surgical aortic valve replacement will be recruited prospectively and consecutively in 5 French centers. A replicative study will be performed in one Austrian center. Echocardiography, cardiac MRI and bone scintigraphy will be performed prior to surgery. During surgery, a basal LV septum biopsy will be collected for determination and quantification of interstitial deposits using specific staining which will be performed in a blind fashion. Clinical outcomes will be recorded during the hospitalization period following the surgery and at 1 year. Alive and re-hospitalization status will be determined. Patients will be classified according to the presence or not of amyloid deposits. Expected results and impact: This study will emphasize how pressure overload stress accelerates and magnifies amyloid deposition usually known to be related to cardiac aging process. It will develop reliable imaging tools and markers to detect cardiac amyloid deposition. Correlation between anatomopathologic analyses and the three different imaging technics will identify accurate imaging markers of CA. A risk stratification model based on amyloid deposits level for the clinical management of these patients will be created combining imaging and biological markers.

In recent years increasing number of mitral bioprosthesis implantation, especially in elderly population, is observed. Bioprosthetic valves are associated with a lower risk of thrombotic and bleeding adverse events compared with mechanical prostheses, but their use is limited due to their durability. After years numerous patients may develop bioprosthesis failure, requiring valve reintervention. Significantly burdened ones are oftentimes disqualified or not referred to surgery redo. An emerging treatment method for these patients is transcatheter mitral valve-in-valve implantation as an alternative to re-operation. This technique is applied with the use of devices previously dedicated to transcatheter aortic valve implantation (TAVI). Recent papers prove that transcatheter mitral valve replacement (TMVR) is a safe and effective procedure when performed in a selected group of high-surgical-risk patients. However, data regarding the Polish population are limited. Therefore, the aim of the study is to create a nationwide registry, collecting data from all Polish centers performing TMVR in order to describe the population of patients developing mitral bioprosthesis failure, evaluate their follow-up after TMVR as well as results of the transcatheter valvular intervention and identify potential limitations of the procedure.

The goal of this trial is to determine whether the use of a novel SGLT2 inhibitor(Sodium-glucose Cotransporter-2), Enavogliflozin is safe and effective for the improvement of adverse clinical outcomes and the reversal of adverse cardiac remodelling among patients who had undergone TAVR as compared with the standard-of-care therapy.

A Clinical Trial of the Transcatheter Aortic Valve Implantation System with a Prospective, Multi-Center, One-Arm Approach to Evaluate the Efficacy and Safety in the Treatment of Patients with Severe Aortic Stenosis

Rationale: Cardiovascular disease and cognitive diseases are closely related. Cognitive impairment is common (21-39%) among patients with severe aortic valve stenosis. The proof-of-concept CP-TAVI study showed that increased cardiac output following transcatheter aortic valve implantation (TAVI) was associated with increased cerebral blood flow. It is hypothesized that increased cerebral blood flow (CBF) subsequently leads to improved cognitive functioning. Additionally, silent micro emboli caused by crushing of the calcified native valve during TAVI may cause cognitive deterioration. If it could be predicted which patients are at risk for TAVI induced cerebral micro emboli, these patients could benefit from cerebral protection devices, preventing cognitive decline. Objective: The objectives of the CAPITA study are 1A) to identify whether an increase in cardiac output after TAVI is associated with an increase of global CBF; 1B) explore regional differences in CBF after TAVI; 1C) determine whether (global or regional) increased CBF is associated with improved cognitive functioning; 1D) identify patient and procedural characteristics associated with increased cardiac output, CBF and cognitive functioning; 2A) identify the incidence and volume of new white matter hyperintensities after TAVI; 2B) evaluate patient and procedural predictors for the increase in white matter hyperintensities volume, including baseline aortic valve calcification volume, measured with computed tomography; 2C) if aortic valve calcification volume predicts new white matter hyperintensities, define a cut-off value for high-risk patients; 2D) assess whether the increase in white matter hyperintensity volume is associated with deterioration of cognitive scores. Study design: Prospective observational study, measuring cardiac output (echocardiography), cerebral blood flow (arterial spin labelling magnetic resonance imaging) and cognitive functioning (neuropsychological test battery) prior to TAVI (<24 hours to <one week) and at 3 months follow-up. At one year follow-up, cardiac output and cognitive function will be assessed. Study population: Patients with severe aortic valve stenosis eligible for transfemoral TAVI (n=142). Main study parameters/endpoints: Cardiac output (L/min), cerebral blood flow (mL/100g/min, change in %, relative to baseline) and cognitive functioning (extensive neuropsychological testing 60-90 minutes).