View clinical trials related to Constriction, Pathologic.
Filter by:Aortic stenosis is the most common valve disease requiring surgery in the Western world. It is defined by progressive calcification and fibrosis of the valve leaflets and restricted valve opening. This in turn exposes the heart muscle (left ventricle) to increasing pressure leading to heart muscle thickening (left ventricular hypertrophy, LVH) to normalise wall stress and maintain heart output (stroke volume). The only treatment available is relief of pressure overload by surgical or minimally invasive valve replacement (TAVI). Transthyretin (TTR) amyloidosis is a condition characterised by deposition of insoluble transthyretin protein (a small protein tetramer produced in the liver) in various tissues, predominantly in the heart. Although there are inherited forms caused by specific TTR gene mutations, most cases occur in older individuals with non-mutated TTR (wild-type). The finding of TTR plaques in elderly individuals is relatively common; in a post-mortem study 22-25% of patients over the age of 80 had evidence of cardiac amyloid deposition. However, there is significant progressive amyloid accumulation in a small percentage of individuals leading to heart muscle thickening and heart failure. No medical treatments are currently licensed although several agents are at advanced stages of clinical trials. As both the above conditions are increasingly common in the elderly population and characterised by increased heart muscle thickening, there is the potential for them to coexist unrecognised in individual patients. The prevalence of cardiac amyloidosis in clinical populations with significant aortic stenosis is not known however small series have estimated somewhere in the region of 6-29%. Other data have suggested that patients with aortic stenosis and concurrent cardiac amyloidosis have an adverse prognosis even despite AVR. It is therefore important to identify aortic stenosis patients with coexistent amyloidosis both in terms of predicting prognosis and because it may influence decisions about whether to proceed to valve intervention. PET/MR is an emerging technique, which combines the excellent temporal and spatial resolution of MRI with the sensitive molecular imaging of PET. PET/MR has significant advantages over PET/CT (the currently more widely used approach) in that it offers superior tissue characterisation, improved correction for cardiac and respiratory motion and major reductions in radiation exposure. Whilst there are concerns about its ability to provide reliable attenuation correction of the PET data, these issues appear to have been largely overcome with recent techniques proposed by our group. MR is also more naturally suited to the imaging of certain tissues in the body compared to CT including the left ventricular myocardium. In aortic stenosis, MRI has become the gold-standard technique for examining the heart muscle (myocardium) with the unique ability to assess its tissue composition. In particular both late gadolinium enhancement (LGE) and T1 mapping based techniques are able to detect heart scarring (fibrosis) which act as biomarkers of left ventricular decompensation and are strongly associated with poor patient outcomes. CMR is also the gold-standard non-invasive technique for detecting cardiac amyloid, which is associated with both a characteristic pattern of LGE and high native T1 values. However it is not currently able to differentiate between the two different types of cardiac amyloid TTR and AL amyloidosis, which have different prognoses and treatments. Preliminary studies conducted by our group have suggested that 18F-NaF PET when added to CMR can make this distinction on the basis that this tracer binds to TTR deposits but not AL deposits, may be able to differentiate between the two. Importantly we have also used the same PET tracer as a marker of calcification activity in the aortic valve, demonstrating its ability to predict disease progression and cardiac events. In this study, we will investigate whether PET/MR could be used as "one-stop" imaging in aortic stenosis in whom valve intervention is being considered to assess in detail functional and structural properties of both the valve and myocardium and identify cases of significant cardiac TTR amyloid deposition.
Feasibility testing of a cap-assisted endoscopic bougienage for benign upper GI stenosis with direct optical control.
Although aortic valve replacement is recommended for any symptomatic severe calcific aortic stenosis, the therapeutic decision may be difficult. because of patient age and comorbidities. Transcatheter Aortic Valve Implantation (TAVI) has recently extended the therapeutic indications in patients at high risk of surgery. However, the proportion of different treatments is not known in a contemporary population that can be treated according to the different resources currently available. The scientific goal of this observational research is to evaluate intra-hospital therapeutic decision in elderly patients referred because of symptomatic severe aortic stenosis. The one-year survival will be analyzed according to the therapeutic decision and the characteristics of the patients.
Aortic stenosis is the most common heart valve disease requiring intervention in high income countries. It is characterised by progressive valvular thickening, and restriction as well is hypertrophy and fibrosis of the left ventricle in response to pressure overload. The pathological processes in the left ventricle that ultimately result in heart failure and death are incompletely understood. Further elucidation of these processes and how they correlate with novel blood biomarkers may help us design new treatments and optimise the timing of surgical intervention. In brief, recruited patients with severe aortic stenosis and scheduled to undergo valve replacement surgery will be invited for some simple tests (blood sampling, ECG, echocardiogram). A septal myocardial biopsy will be taken at the time of surgery and the disease valve retained. These will be examined histologically and pathological changes compared with results obtained from ECG, echocardiogram and blood tests.
The purpose of this study is to determine whether a home-based cycling program for patients with lumbar spinal stenosis is a feasible and acceptable
To evaluate the safety and effectiveness of the SAPIEN XT (Edwards Lifesciences, Irvine, California) transcatheter heart valve implantation (TAVI) in Chinese patients with symptomatic severe calcific aortic stenosis who are considered at high risk for surgical valve replacement.
There are two arms in our trial, DCB group, BMS group.The investigators are going to investigate the safety and efficacy of all groups at 6 months and 12 months.
This study is to compare the clinical outcome between the biportal endoscopic decompression and the unilateral approach bilateral decompression in spinal stenosis
This is a prospective, non-randomized, open label, multi-center study including 60 patients with symptomatic ischemic heart disease with 70%-100% coronary artery stenoses and occlusions enrolled and treated in this investigational device study.
Our hypothesis is that a plasma protein named osteopontin (OPN) could serve as a biological predictive marker of acute AVF dysfunction. In several scientific studies, plasma OPN was correlated with coronary stent restenosis, and with cardiovascular outcome in patients with diabetes and renal insufficiency. This protein is secreted by several cellular types, like distal tubule epithelial cells, macrophages, but also fibroblasts and cardiac and vascular endothelial cells, in response to several specific stimuli. It acts like a cytokine, inducing immunological mechanisms as well as tissue remodeling. The main objective of this study is to show that the amount of plasma OPN is higher in patients presenting with an AVF stenosis, compared with patients with a functioning AVF. OSMOSIS is a monocentric pilot study that will include patients into two groups during 12 months (no specific follow-up). The control group will include patients that have been dialyzed on an AVF, in the dialysis center of Nice University Hospital, for at least 3 months without any incident. The experimental group will include hemodialysis patients hospitalized in the department of vascular surgery for acute AVF dysfunction, needing endovascular or open surgical revision for venous stenosis. Blood will be withdrawn right before dialysis or surgical procedure. Plasma OPN will me measured by ELISA. Their clinical data would be collected from medical file at the same time. After the procedure, patients will be followed-up according to usual protocols. To show a significant difference of 100ng/mL plasma OPN between the two groups, with a power of 90% and alpha risk of 0.05, we plan to include 76 patients