Atherosclerosis Clinical Trials

The proposed study will investigate the clinical use of the ISCDX test that may differentiate between diverse stroke etiologies as listed below: Aim 1: Differentiate between cardioembolic and large artery atherosclerotic ischemic strokes, when hemorrhagic stroke is ruled out, as defined by TOAST classification of subtypes of acute ischemic stroke. Aim 2: In cases of ischemic strokes of unknown or "cryptogenic" etiology, determine the ability of biomarker blood tests to predict etiology between cardioembolic and large artery atherosclerotic. Read Less

South Asian (Indian, Pakistani, Bangladeshi, Nepali, and Sri Lankan) individuals have high rates of cardiovascular disease that is not explained by traditional cardiovascular risk factors. Though South Asians represent over one-quarter of the world's population, there are no longitudinal studies in this high-risk ethnic group. The investigators aim to establish a longitudinal study of South Asians at three United States centers to identify risk factors linked to subclinical atherosclerosis and incident cardiovascular disease. The purpose of this study is to understand the causes of heart disease and stroke in South Asians and compare these causes to those in other United States ethnic groups. Read Less

Emergency Medicine Cardiovascular Risk Assessment for Lipid Disorders (EMERALD) is a protocolized intervention based on American College of Cardiology/American Heart Association and US Preventive Services Task Force guidelines designed to initiate preventive cardiovascular care for emergency department patients being evaluated for acute coronary syndrome. The overarching goals of this proposal are to (1) determine the efficacy of EMERALD at lowering low-density lipoprotein cholesterol (LDL-C) and non high-density lipoprotein cholesterol (non-HDL-C) among at-risk Emergency Department (ED) patients who are not already receiving guideline-directed outpatient preventive care and (2) inform our understanding of patient adherence and determinants of implementation for ED-based cardiovascular disease prevention strategies. Read Less

Background: - Researchers are interested in studying individuals who have known or suspected metabolic or genetic diseases that put them at a high risk for heart diseases or diseases of their blood vessels. To improve the results of the study, both affected and nonaffected individuals will be asked to provide blood and other samples and will undergo tests to evaluate heart and lung function. Nonaffected individuals will include relatives of affected individuals and healthy nonrelated volunteers. Objectives: - To study individuals who have or are at risk for cardiovascular diseases, as well as their unaffected relatives and healthy volunteers. Eligibility: - Individuals between 1 and 100 years of age. Participants may be healthy volunteers, individuals with cardiovascular diseases, or unaffected relatives of individuals with cardiovascular diseases. Design: * Participants will have some or all of the following tests, as directed by the study researchers: * Photography of the face and full body * Body measurements * Radiography, including chest or limb x-rays * Metabolic stress testing to study heart and muscle function * Echocardiography to study heart function * Magnetic resonance imaging (MRI) studies, including cardiovascular MRI, angiography, and contrast MRI, to study heart function and performance * Computed tomography (CT) angiogram to obtain images of the heart and lungs * Positron emission tomography (PET) imaging to study possible fat infiltration of the heart * Six-minute walk test to study heart, lung, and muscle function and performance * Vascular ultrasound to study blood vessel walls * Blood, tissue, and other specimens will be collected for research and testing, and will be taken either as part of the clinical study or during surgical procedures. * Follow-up studies may be performed under separate research protocols. Read Less

Atherosclerosis is the underlying cause of the majority of cardiovascular diseases, including myocardial infarction and strokes, and results in tremendous morbidity and mortality. A Western-type diet is a major risk factor for atherosclerosis because of the high saturated fat, cholesterol, and refined carbohydrate contents. Dietary strategies to reduce cardiovascular disease burden therefore focus on restriction of saturated fat, cholesterol, and refined carbohydrates whereas "lean" protein intake is recommended and has become popular. However, results from studies conducted in animal models suggest high dietary protein intake is also atherogenic. The investigators' extensive preliminary data in animal models show that dietary protein increases atherosclerotic plaque formation and size and promotes necrotic core formation, a characteristic of rupture-prone plaques. The goal of the current proposal is to provide deeper insights into the relationship between protein intake and the pathogenesis of atherosclerosis by studying the mechanisms involved in protein-mediated atherogenesis and formation of necrotic plaques. The overarching hypothesis is that high protein intake drives atherosclerosis via leucine-mediated mTORC1 signaling in macrophages, which inhibits macrophage mitophagy and aggrephagy and stimulates macrophage proliferation. Furthermore, the investigators hypothesize that proteins from animal sources are more atherogenic than proteins from plant sources, because animal proteins contain more leucine than plant proteins. The investigators will test these hypotheses by using a sophisticated array of experimental strategies, including assays in primary macrophages and human monocyte-derived macrophages and genetically engineered mouse models. In addition, they will begin to translate the results obtained in vitro and in animals to people, and explore approaches to pharmacologically target the pro-atherogenic pathways as novel cardiovascular therapeutics. This proposal represents a paradigm shift in how a Western-type diet affects vascular health which has important implications since many adults in Western societies consume excess protein and dietary protein is heavily marketed for its presumed beneficial health effects. Read Less

Background: The right amount of fats in the blood (cholesterol and triglycerides) are a key part of a healthy organism. Too much or too little of these fats may manifest as diseases (dyslipidemia). There are many causes for these abnormalities, but some are genetically determined and we would like to better understand the progression of these conditions over time. Objective: This natural history study aims to learn more about dyslipidemias; how they change over time; and how they respond to therapy. We also want to develop new diagnosis methods for these conditions. With the knowledge we will acquire we hope to provide new insights, new approaches and improve the overall health of these patients. Eligibility: Individuals aged 10 years and older, residing both within and outside the United States, who have or are suspected of having a disorder that causes changes in the levels of fats in their blood (genetic dyslipidemias). Design: Participants residing within and outside the United States will be screened. Their medical records will be reviewed. They may talk to researchers about their medical history by phone, telehealth, or in person. All study visits are optional. Participants may visit the NIH up to 15 times per year, if needed. Each visit may include a physical exam and blood tests. Participants may also have an electrocardiogram (EKG). The EKG measures the electrical activity when the heart beats. Stickers attached to wires will be placed on participants legs, arms, and chest. They will lie still for about 5 minutes. In some cases, participants may remain in the study for up to 20 years. Read Less

This study will evaluate people with dyslipidemias - disorders that affect the fat content in the blood. Fats, or lipids, such as cholesterol and triglycerides, are carried in the blood in particles called lipoproteins. These particles are involved in causing blood vessel diseases that can lead to conditions like atherosclerosis (hardening of the arteries) or heart attack. Participants will undergo accepted medical tests and procedures to evaluate their condition. Most of the test results are helpful in making a diagnosis and in guiding treatment. People with lipid disorders are eligible for this study. Representative types of patients include those with: * Plasma cholesterol levels greater than 200 mg/dl or less than 120 mg/dl * Plasma LDL-C levels greater than 130 mg/dl or less than 70 mg/dl * Plasma HDL-C levels greater than 70 mg/dl or less than 25 mg/dl * Unusual cholesterol deposits or xanthomas (nodules of lipid deposits on the skin) Children under 2 years of age are excluded from the study. Participants will undergo some or all of the following procedures: * Plasma evaluation. Apolipoproteins (plasma proteins involved in metabolism of cholesterol, triglycerides, phospholipids, and proteins in the blood) and enzymes involved in lipid metabolism are measured. * Fat biopsy. A small sample of fat tissue is collected for examination. For this test, an area on the buttock or abdominal wall is numbed. A needle is inserted into the fat, and a small amount of tissue is sucked out by a syringe. * Leukapheresis. White blood cells are collected to help diagnose the lipid disorder. For this test, blood is collected through a needle in an arm vein, similar to donating blood. The blood circulates through a machine that separates it into its components, and the white cells are removed. The rest of the blood is returned to the body, either through the same needle or through another needle in the other arm. * Skin biopsy. Skin cells are collected for study. The cells are grown in the laboratory and the amount of cholesterol that enters or leaves the cells is measured, providing information on abnormalities in cholesterol transport. For this test, an area of skin is numbed with an anesthetic and a small circular area is removed, using a skin punch instrument similar to a sharp cookie cutter. * Heparin infusion study. Heparin, a blood thinner, releases enzymes that break down fat in the blood. Lipase activity (breakdown of fats) in the blood is measured following the injection of heparin into a vein. Read Less

Background: - Imaging tests, such as magnetic resonance imaging (MRI), can provide information about heart and blood vessels. The tests let doctors can see the amount of blood vessel narrowing and vessel wall thickness. This information may help diagnose and treat heart disease and other conditions that lead to heart attacks. Better MRI methods are needed to improve heart disease diagnosis, especially by avoiding the use of radiation. Researchers are testing new techniques to improve the quality of heart MRI, compared with more complex studies like catheterization or angiography. Objectives: - To compare heart MRI techniques with other tests used to diagnose heart disease. Eligibility: - People at least 18 years of age who either have or may have heart disease, or are healthy volunteers. Design: * Participants will be screened with a physical exam, medical history, and blood tests. * They will have an angiography to study the inside of blood vessels. This test is an x-ray study of the blood vessels. It will be done either separately or as part of a set of tests to diagnose possible heart disease. * Participants will have at least one and up to five MRI scans. The scans will involve different methods of studying the heart and blood vessels. Participants may also have a computed tomography scan to confirm the findings of an MRI scan. * No treatment will be provided as part of this protocol. Read Less

The plot study aims to evaluate the effect of 8 weeks of stress reducing intervention on atherosclerotic plaque inflammation in adults, as quantified by positron emission tomography (PET) with fluorine-2-deoxy-D-glucose (FDG) in individuals with increased psychosocial stress. Read Less

Background: - Innate immunity is the process by which white blood cells and other parts of the immune system sense and respond to potential infections by causing an inflammation. Researchers are interested in studying how the body responds to certain environmental factors, and whether the body s response can contribute to chronic illnesses or diseases such as asthma and certain types of cancers. Objectives: - To examine how specific genes and proteins in blood cells respond to environmental exposures. Eligibility: - Healthy volunteers between 18 and 45 years of age. Design: * The study will involve one visit of 45 to 60 minutes. * Participants will be screened with a brief physical examination and finger stick to determine if they are eligible to donate blood for the study, and will complete a questionnaire about any medications or other drugs (e.g., cigarettes) they may be taking. * Participants will provide a blood sample for research purposes. Read Less

The use of handheld arterial 'stethoscopes' (continuous wave Doppler devices) are ubiquitous in clinical practice. However, most users have received no formal training in their use or the interpretation of the returned data. This leads to delays in diagnosis and errors in diagnosis. The investigators intend to create a novel machine-learning algorithm to assist clinicians in the use of this data. This study will allow the investigators to collect sound files from the use of the devices and compare the algorithms output to established, existing vascular testing. There will be no invasive procedures, and use of these stethoscopes is part of routine clinical care. If successful, this data and algorithm will be later deployed via smartphone app for point of case testing in a separate study Read Less

This research will help us to learn if the medicine called metformin reduces the risk of death, heart attacks, and/or strokes in Veterans who have pre-diabetes and heart or blood vessel problems. Read Less