Active clinical trials for "Tetralogy of Fallot"

This study is being conducted to determine what dexmedetomidine does to the body and in turn, what how the body handles the medication. This medication, for the purpose of this trial, is used as a short-term sedative for infants who are immediately post-operative from cardiac surgery and have a breathing tube and are breathing with the assistance of a mechanical ventilator or breathing machine.

The purpose of this study is to evaluate the correlation between fluid volume status and right ventricular volume and function, in those with free pulmonary valve insufficiency after Tetralogy of Fallot (TOF) repair.

The ACHDi Registry study will create a foundational database for adult congenital heart disease interventions. This Pan-Canadian Registry will collect clinical and patient-reported information that will enable the evaluation of care processes and outcomes in five most common ACHDi interventions by enabling prospective and retrospective registry-based studies to answer important clinical practice and policy-relevant questions.

To predict vulnerable patients for aortic root dilatation in TOF patients using CT as a reliable imaging modality, thus aiding early intervention, and identifying those who will require strict follow-up. To assess the prevalence of TOF patients who developed aortic root dilatation, and those who were complicated with dissection, AR, and aneurysm, through collecting data from a large center (Aswan Heart Centre). To investigate the relationship between age at repair and the diameter of aortic root.

The purpose of this early feasibility study is to determine how a new transcatheter pulmonary valve will move and perform once implanted in the right ventricular outflow tract.

Rationale: The prevalence of adult patients with congenital heart disease (CHD) has steadily increased over the last decades, due to the advances in cardiac surgery. A large number of these patients cope with right ventricular (RV) volume or pressure overload, largely caused by residual lesions after cardiac surgery in childhood. Previous RV overload due to pulmonary regurgitation in Tetralogy of Fallot (TOF) can lead to RV dysfunction. These findings warrant close surveillance of RV function, and adequate and evidence-based pharmacological therapy to reduce both morbidity and mortality in this young patient group. The renin-angiotensin-aldosterone system (RAAS) is activated in patients with ventricular failure, irrespective of the effected (left or right) ventricle. Angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARB's) are drugs which act as inhibitors of RAAS. Previously, large trials have demonstrated the beneficial effect of angiotensin converting enzyme (ACE) inhibitors on morbidity and mortality in patients with acquired left ventricular (LV) dysfunction. ARB's have a similar effect as ACE inhibitors in patients with acquired LV dysfunction but discontinuation because of side effects such as cough is less frequent. In TOF patients with RV overload due to pulmonary regurgitation, pulmonary valve replacement leads to a decrease in RV size and pulmonary regurgitation. Current guidelines advise empiric use of RAAS inhibitors for right ventricular dysfunction in adult patients with congenital heart disease. However, the actual effect of RAAS inhibition on right ventricular dysfunction in adult TOF patients without severe valvular lesions has not been sufficiently investigated. Therefore, we set-up the proposed study, and hypothesize that ARB's have a beneficial effect on RV ejection fraction in adult TOF patients with RV dysfunction without severe valvular lesions. Objective: to improve RV ejection fraction in adult TOF patients with RV dysfunction without severe valvular lesions. Study design: a prospective, multicenter, double-blind, randomized, placebo-controlled trial. Follow up two years Study population: adult patients with Tetralogy of Fallot with right ventricular dysfunction, defined as right ventricular ejection fraction < 50% and without severe valvular lesions Intervention: patients are randomized to receive either losartan 150 mg once daily, or placebo in the same regimen. Main study parameters/endpoints: the primary endpoint is difference in change in RV ejection fraction, determined by cardiovascular magnetic resonance imaging (CMR), between the treatment and the control group at two years follow-up. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: All investigations, except blood analysis, are non-invasive and free of risk. The burden for the patients mainly consists of the time that is consumed by the visits to the clinic. At these visits time will be consumed by: history taking and physical investigation (15 minutes); quality of life score (15 minutes); laboratory tests (6 times venopuncture, total amount of blood withdrawn approximately 90ml). Cardiopulmonary exercise testing (1hour), echocardiography (15 minutes) and CMR (45 minutes) are part of regular medical care. Adverse effects from losartan are usually limited and consist of dizziness due to hypotension, renal impairment, hyperkalemia and liver impairment. We expect no change or an increase in RV function in the intervention group compared to the control group over the two-year follow up period, which would be a great benefit for this young study population.

Venus-P Valve (Venus Medtech, Shanghai, China) is the first self-expandable interventional Pulmonary Valve, which is composed of a Nitinol multilevel support frame with a tri-leaflet porcine pericardial tissue valve, and a 14-22 Fr delivery catheter. The purpose of the multi-center trial is to evaluate the safety and efficacy of the Venus-P Valve for percutaneous pulmonary valve implantation (PPVI) in patients pulmonary regurgitation and native right ventricular outflow tract (RVOT) after surgical repair of RVOT.

Background: Residual pulmonary regurgitation following repair of tetralogy of Fallot, in particular the use of a transannular patch, has been shown to correlate with the development of right ventricular dysfunction. Optimal timing of pulmonary valve replacement, therefore, is important to preserve right ventricular function. Several recent studies suggested that a threshold of right ventricular end-diastolic volume for intervention, in order to preserve the likelihood of adequate reverse remodeling, is in the region of 150 to 200 ml/m2 body surface area. However, there is evidence that right ventricular function does not always recover following pulmonary valve replacement even if the end-diastolic volume is below this cut-off. In addition, previous studies suggested that early dysfunction may be present before symptoms occur. However, early dysfunction is difficult to assess. Methods: Analysis of right ventricular function by pressure-volume loops has been extensively evaluated in experimental studies and is generally considered the optimal way to quantify right ventricular function. By recording a family of pressure-volume loops during reduction of preload, achieved by temporary balloon occlusion of the inferior caval vein, the contractility can be calculated by the slope of the endsystolic pressure-volume relation (elastance). Changes of contractility following dobutamine infusion could be noted by changes of elastance. The increase of the slope during dobutamine demonstrates the contractility reserve of the right ventricle. Purpose: To evaluate the right ventricular contractility reserve to determine early ventricular dysfunction after repair of tetralogy of Fallot.

Long term survival of patients with repaired tetralogy of Fallot is excellent (about 85% at 35 year-old). However these patients are exposed to residual pulmonary stenosis (PS) and/or pulmonary regurgitation (PR). It is well established that these lesions can lead to irreversible sequelae such as right ventricle dilatation and dysfunction. Pulmonary valve replacement technique was developed to avoid long term right ventricular dysfunction. Pulmonary valve replacement indications are based upon the presence of symptoms at exercise and/or morphological or functional parameters such as severe pulmonary regurgitation with right ventricle dilatation/dysfunction. The best timing of such intervention is still underdebate with the main aim of having the right balance between avoiding long term sequelae of PR or PS and being the latter possible to push ahead the need for new intervention. Recent publication showed that myocardial diffuse fibrosis can contribute to irreversible alteration of myocardial contractility. Quantification of diffuse fibrosis by magnetic resonance imaging is feasible and could help the physician to best determine the right timing for PVR in this population of patients. Cardiac function assessment at rest and during exercise is possible using MR and our centre has developed a program for cardiac exercise during MRI. This could help to detect infra clinic abnormality and to analyse myocardial adaptation during exercise.

Myocardial protection and clinical outcome in patients Undergoing tetralogy of fallot repair: a randomized study of Two cardioplegic techniques.