Active clinical trials for "Heart Diseases"

Patients who have experienced and survived non-ST segment elevation acute coronary syndromes are often prescribed a combination of aspirin and clopidogrel to thin the blood and prevent further acute coronary episodes. Both clopidogrel and aspirin may cause stomach bleeds and so a prophylactic proton pump inhibitor is frequently co-prescribed in order to prevent such bleeds. Recent mechanistic and observational studies suggest proton pump inhibitors may reduce the effectiveness of clopidogrel and so patients may not benefit as much as expected from combined aspirin and clopidogrel. The investigators propose a cohort study of patients prescribed clopidogrel + aspirin. Amongst these patients the investigators will measure the relative rate of acute coronary syndrome and death comparing patients with and without proton pump inhibitor treatment. To provide a more complete picture of the risks and benefits of treatment the investigators will also measure the relative rate of stomach bleeds in the same groups of patients. In addition, whether the inhibitory effect of proton pump inhibitors on the protective effect of clopidogrel is due to their inhibition of drug metabolising enzymes will be explored by assessing the effects of other drugs that inhibit the same enzymes.

Background: - Heart failure is a common cardiovascular disorder whose incidence increases with age, affecting up to 10% of people older than 65 years of age. As the population ages, the prevalence and cost of heart failure will continue to rise. Researchers are interested in using noninvasive imaging methods to better understand the symptoms and effects of heart failure. Objectives: - To conduct a noninvasive comparative imaging study of individuals with heart failure. Eligibility: - Individuals at least 18 years of age who have been diagnosed with heart failure (with at least mild symptoms and slight limitations on physical activity). Design: This study will last approximately 2 years and will require four visits to the National Institutes of Health Clinical Center, with one screening visit and three study visits. Participants will be screened with a full medical history and physical examination, as well as blood and urine samples. Participants will have the following tests during each study visit: Physical examination Blood and urine samples Cardiac magnetic resonance imaging Cardiac computerized tomography to study the blood vessels in and leading to the heart Echocardiogram to evaluate heart function Electrocardiogram to measure heart electrical activity The three study visits will take place 1 year apart. Participants will also receive follow-up phone calls 6 months after the first and second visits. No treatment will be provided as part of this protocol.

The purpose of this study is to determine whether cardiopulmonary bypass affects mesenteric microcirculatory function, using sublingual evaluation, in cardiac surgery.

Identification of the pathophysiology associated with Eisenmenger's syndrome has led to the evaluation of targeted therapies. Iloprost, a prostacyclin analogue, is one such targeted therapy used in patients with Eisenmenger's syndrome. The purpose of our study is to assess the effects of inhaled iloprost on patients with Eisenmenger's syndrome.

This is a prospective, single-center study that aims to evaluate the acute and delayed effect of exercise stress testing on the peripheral gene expression (PGE) levels using a predefined gene set established in the Corus CAD (Age/Sex/Gene Expression score - ASGES) test in subject with known obstructive coronary artery disease (CAD) and in control subjects (without known CAD).

This investigation is designed to demonstrate the clinical safety of the EVIA/ ENTOVIS pacemaker system when used under specific MRI conditions.

Retrospective medical record review study of specific adverse events in children with congenital heart disease who received palivizumab for prophylaxis of serious respiratory syncytial virus infection and control subjects that did not receive palivizumab

Prematurely born infants with ductal-dependent congenital heart disease (CHD) are at increased risk to develop necrotizing enterocolitis (NEC). Abnormal left to right blood flow through a patent ductus arteriosus can cause intestinal ischemia and compromise the gastrointestinal tract as a barrier to infection. In some infants, bacterial translocation leads to NEC which may result in death, intestinal perforation, cholestasis and, at the very least, feeding problems. Predicting which infants with CHD will develop NEC will potentially decrease the severity of disease if interventions were started earlier. Near-infrared spectroscopy (NIRS) allows determination of regional oxygen saturation levels in tissues such as brain, kidney, and as recently reported, intestine. This study will test whether or not decreasing intestinal oxygen saturations can predict the development of NEC in this at risk population before the symptoms become severe. NIRS probes will be placed on the forehead, flank and abdomen of eligible infants and regional oxygen saturations will be recorded prospectively and continuously with the clinical care team blinded to the data. The development of NEC and significant feeding problems will then be correlated with the regional oxygen saturations to determine whether decreased intestinal oxygen saturations predicted early signs and symptoms of NEC. We anticipate generating pilot data in 30 infants who meet inclusion criteria. Support of this research will be provided partially by Somanetics, the manufacturer of the INVOS regional oxygen saturation monitors. They will, however, have no control over the data generated by this study.

Numerous human cardiac stem cell studies have been published, including relatively small number of patients. Meta-analysis of randomized trials have reported safety and a 3-6% increase in global left ventricular performance after intracoronary stem cell therapy in patients with acute myocardial infarction. Since most of the studies used different type of stem cells, delivery modes, and patient population, the results are heterogenous, therefore the comparison of the results is biased regarding generalizable conclusions about the effect of treatment. The present comparative meta-analysis is based on individual patient data, and gathers and pools the raw data, and analyzes the clinical outcome, safety and efficacy of the cardiac stem cell therapy.

Magnetic resonance imaging (MRI) and echocardiography are two imaging methods that are used to obtain pictures of the heart and assess heart function. This study will evaluate a new, four-dimensional echocardiography approach of obtaining heart images to determine if it is as effective at evaluating heart function as MRI.