38 Clinical Trials for Various Conditions
Many studies have shown that if the human body is stressed by a lack of blood flow for a short period of time, the body develops defenses to make the body more resistant to a future stress from lack of blood flow. This natural defense system is called preconditioning. Finding medications that have a preconditioning effect to protect against damage from loss of blood flow would be of great help in the treatment of diseases such as heart attacks and stroke that occur because of blockages of blood flow. Predicting future heart attacks or strokes is very difficult and makes it difficult to study medications that could have a preconditioning effect. However, it has recently been recognized that we can mimic the preconditioning effect in the human arm, by blocking blood flow using a blood pressure cuff under pressure. Here, blowing up the cuff for 5 minutes and then letting the pressure out for 5 minutes and repeating this process twice more (a way to precondition the arm), has been shown to improve blood vessel function in response to a longer period of blood pressure cuff inflation (20 minutes). As nitrite, a naturally occurring blood substance, has biological effects suggesting that it may mimic preconditioning. The main objective of this study is to assess whether nitrite is equivalent to preconditioning in its capacity to protect the forearm blood flow in response to a 20 minute blockage of blood flow by blood pressure cuff inflation of the forearm. We hypothesize that in human subjects the ischemic preconditioning program works through activation of the pool of nitrite in the blood stream. Moreover, we propose that nitrite treatment will improve (1) blood vessel recovery (2) skeletal muscle blood flow and (3) skeletal muscle mitochondrial function and (4) reduce the activation of inflammation in response to the 20 minute stress of blood pressure cuff inflation.
The purpose of this study is to evaluate the blood flow to the heart during stress and assess changes in blood flow after psychological treatment in participants with coronary artery disease. The aims of the study are to assess the effects of heart rate variability (HRV) biofeedback (versus usual care) on global and regional myocardial blood flow (MBF), peripheral vascular function, and autonomic changes during mental stress.
The purpose of this study is to look at the link between emotional stress and heart disease in men and women. Taking part in this study involves one clinic visit, one week of at home monitoring, and follow up phone calls every 6 months for 3 years.
Hyperglycemia is present in 50 percent of patients with acute ischemic stroke. Patients with hyperglycemia have higher in hospital, 30 and 90 day mortality and morbidity. Sixty percent of these patients have some form of diabetic syndrome, known or unknown. Remaining 40% of patients are not diabetic. Contrary to logic patients with non diabetic hyperglycemia (NDH) have statistically higher morbidity and mortality compared to the diabetic hyperglycemia (DH) cohort. So far multiple treatment trials (THIS, GRASP, GIST-UK, SHINE ongoing) with differing treatment goals have shown no clear benefit, however no obvious distinction was made along the diabetic and non-diabetic hyperglycemic groups. If hyperglycemia in the acute phase was the only culprit in worsening the injury, then there should be no difference in the outcomes for DH and NDH. Existing data implies that the two categories are two distinct physiological entities that are thus not amenable to same treatment. Stating it simply NDH is not an insulin deficient state where as DH is. Alternative possibility is that body and Neurons are accustomed to high sugars in diabetics and thus can tolerate higher sugars better during ischemic stroke compared to non diabetics. The overarching hypothesis is that reducing blood sugars in NDH increases stroke volume and thus consequently worsens outcome.
Coronary artery disease (CAD) remains the leading cause of death in the elderly. Silent myocardial ischemia (SI) is a manifestation of CAD in which there is a transient alteration in myocardial perfusion, function, and/or electrical activity not accompanied by chest pain. Mental and emotional stress, in particular hostility and anger are potent inducers of SI, Individuals with SI are at a 3-5 fold higher risk for the development of angina, myocardial infarction and death than subjects without SI.
Depression is commonly seen in patients with cardiovascular disorders. In recent studies it has been shown that mild to moderate depression symptoms were associated with increased likelihood of mental stress-induced myocardial ischemia (MSIMI), which is a risk factor of poor cardiac outcome. In this project, the investigators aim to assess the treatment of mental stress-induced myocardial ischemia in ischemic heart disease patients with mild to moderate depressive symptoms. This study is a six-week double-blind placebo controlled study to examine the effects of escitalopram on mental stress-induced myocardial ischemia. This study will look to show that patients with ischemic heart disease who are treated with escitalopram will exhibit a significant improvement of MSIMI at the end of week 6 compared to patients receiving placebo.
This prospective, observational study evaluates the accuracy of stress testing with the MyoStrain SENC CMR Imaging System to detect myocardial ischemia and viability in patients with suspected coronary artery disease using low levels of stress.
The principal objective of the study is to evaluate the effectiveness of a widely used complementary medicine intervention, mindfulness-based stress reduction (MBSR), in which mindfulness meditation and yoga are the principal components in the treatment of a chronic, often fatal illness that affects tens of millions of Americans. The investigators propose to conduct a single center randomized controlled trial in which 150 patients will be assigned to either a mindfulness meditation condition, a disease education control condition, or a stress-monitoring usual care control condition. They will test the following specific hypotheses: 1. In comparison to either of the control conditions, significantly more coronary artery disease (CAD) patients in the mindfulness meditation condition will demonstrate reductions in mental stress-induced ischemia. 2. The ratio of low-to-high frequency of spectral power in heart rate variability during ambulatory monitoring will be significantly decreased following the participation in a stress reduction program compared with those in a disease education or usual care condition. 3. Patients in the mindfulness meditation condition will report greater improvement in quality of life (i.e., reductions in general psychological symptomology, anger, anxiety, depression, and daily stress, along with increases in optimism and stress coping efficacy) than patients in either of the control conditions. 4. Day-to-day variability in self-reported mental stress will be inversely related to day-to-day stress coping efficacy in the entire sample and time spent in mindfulness practice in the active treatment condition, and these relationships will be maintained over a 3-month follow-up. 5. Patients with CAD and mental stress ischemia who show an \*abnormal peripheral artery response during baseline studies will show a significant improvement after mindfulness intervention. * Abnormal responses will be defined as peripheral arterial tonometry (PAT) tracings that decrease greater than 20% in amplitude during mental stress.
This is a single center, randomized controlled trial which will include women with ischemic heart disease to receive either a self-directed stress reduction program delivered through a smart-phone application or activity tracking only for the first month ("early SR intervention" and "delayed SR intervention", respectively). Patients will be monitored for 1 month for application use and step counts via telephone or email interview and/or collection of screen-captured data. Baseline questionnaires will be repeated at the end of one month to assess for all primary and secondary measures, at which time the control group (activity tracking only) will be introduced to the intervention program. The early SR intervention group will not receive a new intervention but will be encouraged to continue using the app. Data will be collected for an additional 2 months with all participants in both groups. After the three-month study period, the study will close with the collection of final questionnaire data.
The broad objective of this study is to test the association between hyperoxia exposure after resuscitation from cardiac arrest and outcome. After obtaining written informed consent subjects enrolled in REOX II will undergo a rapid faction of inspired oxygen (FiO2) optimization protocol to prevent exposure to hyperoxia. We will compare outcomes between subjects enrolled in REOX I (observational study only) and REOX II (intervention: rapid FiO2 optimization protocol). Our overarching hypothesis is that exposure to hyperoxia after return of spontaneous circulation (ROSC) is associated with increased oxidative stress and worsened neurological and cognitive outcomes.
The broad objective of this study is to test the association between hyperoxia exposure after resuscitation from cardiac arrest and outcome. Our overarching hypothesis is that hyperoxia after ROSC is associated with increased oxidative stress and worsened neurological and cognitive outcomes.
This research aims to investigate whether symptoms of chest pain or shortness of breath among the study population are arising due to a heart problem, particularly any reduction of blood flow to the heart muscle from blockages in the coronary blood vessels or inflammation of the heart using cardiac magnetic resonance imaging that measures the amount of blood flow during a stress state meant to simulate vigorous exercise. At present, doctors use standard magnetic resonance imaging pictures of blood flow patterns to treat heart disease. The investigators want to study if detailed blood flow measurements, in addition to the standard blood flow pattern, could diagnose heart disease more accurately and allow more doctors to understand the severity of heart disease. Early research has demonstrated that detailed blood flow measurements may be more accurate in diagnosing heart disease in some patients, but doctors need more information to know how to use these measurements.
This research is being done to try to improve the experience of mothers and babies during therapeutic hypothermia. Currently, mothers are not able to hold their baby during hypothermia treatment. Mothers have reported that not being able to hold their baby during this time is stressful. Additionally, it is known that holding has many benefits for mothers' and babies' psychological and physical health. Therapeutic hypothermia is the standard of care. The experimental interventions of this study are to have mothers hold their babies during this treatment, collect saliva samples from mothers and babies, and test the saliva samples for the hormones cortisol and oxytocin. The investigators will test saliva of infants and their mothers before and after holding. The investigators hope to demonstrate decreased cortisol, a marker for stress, and increased oxytocin, a marker for bonding, in infants and mothers while they are held during therapeutic hypothermia.
We propose a single-scan two-injection myocardial perfusion imaging protocol using ammonia. Subjects will undergo single-scan two-injection imaging as well as regular stress single-scan single-injection protocol and the myocardial blood flow of both techniques will be compared.
Numerous single-center studies have indicated gadolinium-enhanced stress CMR perfusion imaging has excellent diagnostic accuracy for coronary artery disease and negative clinical event rates, with its diagnostic accuracy exceeding nuclear scintigraphy. However, current prognostic evidence supporting clinical use of stress CMR is limited by study size, single-center settings with a predominance of academic centers, and a lack of "real-world" study design. Large-scale multicenter real-world evidence from a registry will provide the much needed information to guide evidence-based clinical adaptation that benefits patient care.
Ten infants undergoing therapeutic hypothermia for hypoxic-ischemic encephalopathy will be enrolled in a new protocol that will allow mothers to hold their infants during the hypothermia treatment period. This is a safety study that will assess whether or not there is an increase in adverse event frequency in infants that are held during hypothermia. Parents and NICU nurses will be given a questionnaire after holding is complete investigating their feelings on maternal-infant bonding and safety of the holding protocol.
Regional absolute myocardial blood flow during stress (sMBF) as measured by Positron Emission Tomography (PET) improves post mechanical revascularization provided there is a baseline stress induced perfusion defect. Coronary revascularization performed on regions without a stress induced perfusion defect does not increase the sMBF.
The goal of this clinical research study is to compare regadenoson nuclear stress testing with echocardiography strain measurements (an ultrasound imaging method that measures hearts function) in detecting coronary artery disease.
Our hypothesis is that quantitative 3D analysis of cardiac CT images obtained during vasodilator stress can accurately identify patients presenting at the emergency department with acute chest pain due to underlying hemodynamically significant coronary stenosis, aid in the identification of individuals most likely to benefit from revascularization, and thus improve the ability to predict patient outcomes. Our goals are: 1. to test the above hypothesis by comparing stress MDCT perfusion data with invasive fractional flow reserve (FFR) data in patients with significant stenosis who undergo ICA; 2. to determine the added value of MDCT perfusion as an adjunct to CTCA for predicting patient outcomes.
The investigators plan to use retrospective data to assess heart function and structure abnormalities through the use of an approved vasodilating agent for stress cardiac MRI tests. The investigators are interested in how these MRI findings relate to long-term prognosis in people who are at risk for cardiac disease.
The objectives of this study are to determine the: 1. Diagnostic value of stress induced RV changes on Lexiscan stress MPI as compared to Exercise stress MPI in predicting a significant CAD. 2. Prognostic value of stress induced RV changes on Lexiscan stress MPI in predicting adverse short-term and long-term clinical outcomes after the index test.
Coronary artery disease (CAD, coronary heart disease) is the leading cause of death in the U.S., causing 1 in 5 deaths in 2005. The current method for diagnosing coronary artery disease that is considered most accurate is coronary angiography however it involves risk and radiation. Alternatively nuclear imaging test and MRI stress test only permits the semi qualitative analysis of the myocardial perfusion images. In this proposal the investigators will develop a means to calculate Coronary Flow Reserve (CFR) using the MRI. the investigators approach has the potential to reduce mortality from myocardial infarction by effecting a change in the patient management paradigm. Absolute quantification of myocardial perfusion will detect coronary stenosis and CAD in patients with more accuracy than the semi-quantitative or qualitative analysis of perfusion images. Measurement of Coronary Flow Reserve is important for the following reasons: decrease of coronary flow reserve has been identified as a first effect of CAD; it provides an objective measure of treatment efficacy. The purpose of this study is to compare images from nuclear stress test and/or coronary angiography with Magnetic Resonance Imaging (MRI) that will evaluate subjects with coronary artery disease calculating myocardial blood flow using a novel MRI technique combined to an extracellular Gadolinium-based contrast agent and stressor agent
The current study is designed to have broad generalizability and inform a potential shift toward greater utilization of stress echocardiography with UCA. This will be accomplished by comparing UCA stress echocardiography with myocardial SPECT among hospitalized patients presenting with atraumatic chest pain. This study seeks to demonstrate: clinical comparability of the 2 modalities (based on non-diagnostic test rates), improved care efficiency (based on length of stay), lower costs, improved provider satisfaction, and a presumed improved safety profile through the elimination of radiation exposure. Primary Hypothesis: A strategy of routine UCA (Optison™) enhanced stress echocardiography will result in a clinically non-diagnostic test rate comparable to myocardial SPECT among patients hospitalized (inpatient or hospital observation status) with atraumatic chest pain.
Objective: The objective of this pilot study is to characterize the cardiac uptake patterns of I-123 mIBG in stress-induced (Takotsubo's) cardiomyopathy. Hypothesis: Perturbations in sympathetic innervation are the underlying pathogenesis of stress induced cardiomyopathy and will result in abnormalities in I-123 mIBG cardiac imaging. Thus, planar and SPECT I-123 MIBG imaging will provide insight into the pathogenesis of stress-induced cardiomyopathy, and may lead to the development of more specific diagnostic criteria. Study design: This proposal is for a prospective pilot study to characterize perturbations in cardiac sympathetic innervation in patients with stress induced cardiomyopathy by performing planar and SPECT I-123 MIBG imaging during the acute presentation and after recovery of LV function.
The purpose of this study is to compare Multidetector Computed Tomography (MDCT) and Single Photon Emission Computed Tomography (SPECT) stress myocardial perfusion imaging (MPI) with regadenoson in order to detect the presence or absence of reversible defects.
Many stress tests being done today have two parts, the stress test and the pictures of your heart. The investigators are comparing a newer technique to obtain the pictures (PET imaging) to the standard method (SPECT imaging). However, it is not known if the new test is better than the old test. It is important to have a standard to compare these tests to, and that is why people who will be getting a cardiac catheterization are being asked to participate. The information about your arteries from the cardiac catheterization will be used to judge which stress test is better. The investigators hypothesize that the newer method (PET imaging) will be more accurate than the old method (SPECT) in detecting heart disease.
Cardiac stress testing with functional nuclear imaging is an invaluable technique in the diagnostic and prognostic evaluation of patients with known or suspected ischemic heart disease. Selection of the appropriate type of nuclear stress test: exercise stress Myocardial Perfusion Imaging (MPI) versus pharmacologic stress MPI is crucial for not only diagnostic accuracy and prognostic evaluation, but also for sound clinical decisions and resource utilization. The Duke Activity Status Index (DASI) is a 12-item questionnaire that utilized self-reported physical work capacity to estimate peak metabolic equivalents (METs) and has been shown to be a valid measurement of functional capacity. The investigators hypothesized that the DASI may be the screening tool that evaluates functional capacity and guides selection of the optimal stress MPI study.
The main purpose of this study is to get more information on using BMS747158 (the study drug),a drug with small amounts of radioactivity to allow for heart imaging, during a PET scan which can then be compared to other images such as SPECT. The safety and quality of images will be studied.
Oxidative stress has been linked to many diseases associated with aging, including coronary heart disease and Alzheimer's disease. Antioxidants and special proteins in the body work together to help prevent damage by free radicals. Some studies have indicated that as people age, they are less able to fight off oxidative stress and have increased levels of inflammation. Tart cherries are known to be rich in antioxidants and plant-nutrients. The product we are using in this study is an all-natural tart cherry juice, mixed with apple juice concentrate and containing no additives and no preservatives. We hope to learn whether antioxidant supplementation, such as tart cherry juice, can measurably decrease oxidative damage and inflammation associated with aging.
This study will compare the physiologic responses between exercise stress echocardiography and pharmacologic stress echocardiography on left ventricular volume and wall stress.