Active clinical trials for "Aortic Valve Stenosis"

With the introduction of the CoreValve™ Evolut R™ 34mm (Medtronic™) prosthesis, patients with severe symptomatic aortic stenosis (AS) and large aortic annulus have become eligible for transcatheter aortic valve implantation (TAVI). The aim of this study is to detect the number of TAVI candidates with large aortic annulus, and to evaluate the feasibility, efficacy, and safety of TAVI using the CoreValve™ Evolut R™ 34mm.

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.

Multicentre prospective registry including consecutive patients undergoing Percutaneous Endovascular Aneurysm Repair (PEVAR), Percutaneous Endovascular Thoracic Aneurysm Repair (PTEVAR) or Transcatheter Aortic Valve Implantation (TAVI) in which variables related to the percutaneous access closure for implanting devices at aorta level will be collected and analyzed. The follow-up period will be 30 days after the procedure. The duration of the recruitment period will be one year. All data will be collected telematically and incorporated into a database for subsequent statistical analysis. There will be 2 points for data interim analysis at 6 and 12 months after initiation of the study.

an international multicentre registry designed to answer 3 clinical questions: Describing the characteristics and outcomes of current patients undergoing aortic + mitral transcatheter heart valve procedures. Better understanding of the predictors for MR regression following isolated TAVI and consequently estimating the fraction of patients who will be suitable for TMVR/r post TAVI Examining the clinical outcomes of patients with significant MR post TAVI who subsequently underwent TMVR/r compared to those left for medical management.

When aortic valve-area is <1.0cm2 and transvalvular mean-gradient is >40mmHg, the diagnosis of severe aortic stenosis (AS) is straightforward. However, some patients present with an apparently reduced valve-area, despite transvalvular-gradient <40mmHg; Low-flow, low-gradient aortic stenosis (LFLG AS). When a patient with LFLG AS also presents with LVEF <50%, guidelines recommends performing a Low-Dose Dobutamine-echocardiography (LDDE) to confirm true-severe AS. However, nearly 30% of patients with LFLG AS do not show an adequate respond to Dobutamine. More commonly, patients present with the combination of LFLG AS, despite LVEF≥50%. In this group of patients the use of LDDE remains undisclosed. The purpose of this study is to examine the safety and diagnostic usefulness of LDDE in patients with LFLG AS with LVEF≥50%. Furthermore we will examine factors associated with inadequate response to LDDE. 150 symptomatic and/or asymptomatic patients with LFLG and LVEF≥50% and a control group with LVEF<50% will be enrolled at the Department of Cardiology, OUH. Patients will undergo clinical evaluation including LDDE, blood analyses, CT-scan and cardiac Mri. Only a limited number of studies examine the possible use of LDDE in patients with LFLG AS and LVEF≥50% and no study has been performed documenting the safety and feasibility.

Research aims The increasing prevalence of severe aortic valve defects is a corollary to increases in life expectancy. For many years, surgical valve replacement with extracorporeal circulation has been the gold standard in the treatment of severe aortic valve diseases. Every year, about 12,000 patients in Germany receive isolated aortic valve surgery. Several alternatives to established procedures have recently emerged: V-TAVI, vascular transcatheter aortic valve implantation and A-TAVI, apical transcatheter aortic valve implantation. For some time, percutaneous balloon valvuloplasty has been used as a palliative measure for specific patients. New developments have triggered assumptions that there will over the coming years be a certain reorientation to the treatment of patients with aortic valve defects. In a positioning paper published jointly by the German Cardiac Society (DGK) and the German Society for Thoracic and Cardiovascular Surgery (DGTHG), there is a consensus that these new techniques can be used on patients who have either contraindications against conventional surgery or who are at high risk of preoperative mortality, e.g. due to severe comorbidities. As there is as yet only limited experience in this field and neither randomised trials nor long-term-results are available, the use of new implantation techniques is therefore not recommended for younger patients or patients without comorbidities. There is accordingly an urgent need for any introduction of this innovative medical procedure to be stringently monitored according to scientific principles. The goal of the planned Germany Aortic Valve Register is to evaluate the new treatments from the point of view of benefits und risks with respect to the gold standard of conventional surgery, with a view to compiling evidence-based indication criteria. The register will furthermore allow for the first time a comparison of various operative procedures, such as Ross procedure, David procedure and various mechanical or biological aortic valve implants. Rationale of the study design Randomised trials in controlled environments are considered best scientific practice for verifying the efficacy of a new method. The disadvantage is that only a small part of potential patients can be included in the trial, and results therefore reflect only a small section of the real world. Furthermore, a randomised study design is for ethical reasons not an acceptable approach to all questions, especially when contraindications exist for a certain branch of treatments and the spectrum of treatments is to be expanded. Nevertheless, new procedures have to be critically and scientifically analysed if the risk-benefit ratio is to be accurately determined. National heath authorities therefore request register data in addition to controlled trials in order to verify the safety and efficacy of new procedures across larger patient populations. Objectives Description of structure, process and outcome quality for the various techniques of aortic valve therapies Definition of indication criteria (e.g. through scoring systems) Collection of information on quality and safety for special medical devices Evaluation of quality of care on the level of participating centres with a view to increasing quality Health economic evaluation of the applied treatments Study design Prospective, controlled, multicenter register study

Aortic stenosis (AS) is AS is caused by calcium deposits in the aortic valve. Calcification is progressive and eventually leads to reduced leaflet motion with obstruction of the left ventricular outflow. The only treatment is surgery. There are evidences that AS is a regulated process with similarities to atherosclerosis but determinants of AS progression are unknown. The study aims at evaluating these determinants and more specifically the role of lipids, inflammation and platelet aggregation.

A prospective, multicentric cohort study including 166 patients with symptomatic aortic stenosis treated with transcatheter aortic valve implantation (TAVI). - The main objective is to determine whether the high residual platelet reactivity rates in patients undergoing TAVI is associated with the occurrence of clinical and / or subclinical prosthetic valve thrombosis measured by echocardiography and multi-slice computerized tomography

Introduction and aims: Transcatheter aortic valve replacement (TAVR) is the gold standard for the treatment of elderly patients with severe aortic valve stenosis (AS). AS causes left ventricular remodeling as well as left atrial enlargement, pulmonary artery and right ventricular changes, these changes, and whether they are reversible (reverse remodeling) are major determinants of outcome after TAVR. Heart Failure (HF) is the most frequent cause of cardiac re-hospitalization after TAVR. Most HF exacerbations are related to a progressive rise in cardiac filling pressures that precipitates pulmonary congestion and symptomatic decompensation. Traditionally, pulmonary congestion has been assessed by physical examination and chest radiography but clinical signs and symptoms of congestion are poor surrogates for ventricular filling pressures and are not reliable predictors of imminent hospitalization. Recently, lung ultrasonography (LUS) has been identified as a sensitive and semi-quantitative tool for the assessment of pulmonary congestion in HF. The technique is based on the detection of vertical echogenic artifacts arising from the pleural line, named "B-lines". The number of B-lines is associated with increased risk of adverse events during hospitalization and after hospital discharge. CLUSTER-HF Trial demonstrated that the routine incorporation of LUS during clinical follow-up of patients with recent acute decompensated HF without a surgically correctable cause, was associated with a risk reduction of adverse HF events, mainly urgent HF visits. Thus, LUS could represent a promising tool to detect pulmonary congestion related to AS. To date, there are no studies on the role of LUS in the context of AS and TAVR. The study hypothesis is that in patients with higher number of B-lines before-TAVR and after TAVR, the rate of adverse events during follow-up is higher. Study design: This is a single center prospective study carried out at Fondazione Policlinico Gemelli IRCCS, Roma and involving patients with severe aortic stenosis submitted to TAVR treatment. The expected recruitment period is approximately one year For patients fulfilling inclusion/exclusion criteria, all data about clinical status leading to TAVR, exams and any specific documentation during hospitalization will be collected. Number of patients: For the primary end-point, a sample-size of 91 is computed using the one-sample chi-square test and assuming a proportion of LUS-evaluated pulmonary congested patients before TAVR of 50% and a proportion of 35% of LUS-evaluated pulmonary congested patients after TAVR. To accommodate for possible missing investigations, sample size will be increased to 105 patients. The secondary end-point is the association between pre-TAVR and post-TAVR B-lines and long-term outcomes. Based on previous studies, the investigators know that the incidence of rehospitalization for heart failure during one-year after TAVR is 14% and that patients suffering from heart failure without LUS-evaluated pulmonary congestion are at very low risk of heart failure rehospitalization during follow-up. So, for sample size calculation of the secondary endpoint, the investigators estimated a cumulative incidence higher in the LUS- evaluated pulmonary congestion group with more than 16 B-lines on all scanning sites (30% of events during 1-year of follow-up) with a lower incidence of 8% in the remaining patients. With an HR of 5 favoring patients wit less than 15 B-Lines on all scanning, and aiming to a 2-sided alpha level of 0.05 and a power of 80% the investigators estimated 144 patients. To accommodate for possible missing investigations, sample size will be increased to 150 patients. In-hospital study schedule: For each patient, the investigators will obtain from our general hospital database the following clinical data: Demographic and clinical data documentation; Clinical examination: before TAVR, before discharge and when adverse events occur; Blood analysis; TAVR procedural characteristics and complications. Instrumental diagnostic exams (Echocardiography and lung ultrasound): Each patient will be evaluated before and after TAVR with a comprehensive echocardiogram and LUS for the evaluation of the pulmonary congestion. All the evaluations will be performed the day before TAVR and after TAVR. In consideration of the operator's dependence on ultrasound methods to reduce the error rate, all examinations will be performed by qualified personnel. Clinical follow up assessment: Clinical follow up information will be obtained from: visits, review of the patient's hospital record, personal communication with the patient's physician and review of the patient's chart, a telephone interview with the patient conducted by trained medical personnel The following information will be recorded: clinical status assessment, adverse event assessment, record cardiac medications.

This study investigates the effect of margarines supplemented with plant sterol esters on serum and cardiovascular tissue concentrations of plant sterols. We assume that consumption of margarine supplemented with plant sterol esters increases serum and cardiovascular tissue concentrations of plant sterols (sitosterol; campesterol).