Active clinical trials for "Arteriosclerosis"

The study will examine the effects of estrogen and progesterone on the development of atherosclerosis in menopausal women when hormone treatment is initiated within 3 years of the menopausal transition.

This study will measure and compare the levels of endothelial progenitor cells (EPCs) in the blood of people with and without risk factors for atherosclerosis (hardening of the arteries) to see if there is a relationship between these cells and cardiovascular risk factors such as smoking, high cholesterol level and high blood pressure. Healthy male volunteers between the ages of 21 and 55 years with and without heart disease risk factors may be eligible for this study. Candidates must have no evidence of coronary or peripheral vascular disease, proliferative retinopathy, or other chronic disease and no history of cancer, migraine-type headache, cluster headache, raised intraocular pressure, raised intracranial pressure, hyperthyroidism. Participants will undergo the following procedures at the NIH Clinical Center: Medical history and physical examination Blood tests to measure EPC level and various risk and growth factors Brachial reactivity study - This ultrasound study tests how well the subject's arteries widen. The subject rests on a bed for 30 minutes. An ultrasound measuring device is placed over the artery just above the elbow. The size of the artery and blood flow through it are measured before and after inflating a pressure cuff around the forearm. The pressure cuff stops the flow of blood to the arm for a few minutes. After a 15-minute rest, the drug nitroglycerin is sprayed under the subject's tongue. Before the nitroglycerin spray and 3 minutes after it, the size of the artery and blood flow through it are measured again.

To determine familial and non-familial causes for susceptibility to atherosclerosis and the inflammatory response.

To investigate the relationship between endogenous estrogen and androgen levels and risk of coronary heart disease among postmenopausal women in the Women's Health Initiative-Observational Study (WHI-OS).

To determine if risk factors measured in childhood can predict the development of atherosclerotic coronary and carotid artery disease in adulthood.

To determine the effects of long-term exposure to passive smoking on the cardiovascular and oxygen transport systems in pre-adolescent twins.

To localize, identify, and evaluate common polymorphic variation in genes involved in determining interindividual differences in blood pressure (BP) levels and essential hypertension status in three racial groups: African-Americans, Mexican-Americans, and Non-Hispanic Whites. The study consists of a six grant network, which in turn is part of an NHLBI initiative, the Family Blood Pressure Program (FBPP) consisting of four networks.

This study will look at the effect of a cardiac rehabilitation exercise program on release of stem cells from the bone marrow and on heart function. Stem cells are primitive cells produced and released by the bone marrow, circulate in the bloodstream and develop into white blood cells, red blood cells and platelets. Some stem cells may also develop into other kinds of cells, including those that make up heart muscle, especially if the heart has been damaged or is not getting sufficient blood. Stem cells called endothelial progenitor cells (EPCs) are thought to form new blood vessels that can carry blood to areas of the heart muscle that are oxygen-deprived because of clogged arteries. Previous experiments have shown that some EPCs can be forced out of the bone marrow by exercise. This study will examine whether repeated exercise and lifestyle changes increase the number of EPCs released into the bloodstream and if these cells improve heart and blood vessel function. Patients 21 years of age and older with coronary artery disease may be eligible for this study. Candidates will be screened with a medical history and physical examination, including a cardiovascular evaluation, and blood tests. The participants will be enrolled in a 2- to 3-month cardiac rehabilitation program that includes 24 to 36 60-minute sessions of exercise, plus instruction on lifestyle changes related to diet, stress management, and relaxation techniques. In addition, participants will undergo the following tests and procedures: Brachial reactivity study: This test measures how well the arteries widen. The patients rest for 30 minutes, and then an ultrasound device is placed over the artery just above the elbow. The device measures the size of the artery and blood flow through it before and after the patient is given a spray of nitroglycerin under the tongue. Blood tests for EPC levels and genetic testing: These measure EPCs and determine whether certain genes that may regulate EPC function are turned on or off. Genes are made up of DNA, the molecules that lead to the production of proteins by cells. Some of these proteins may be important in releasing EPCs from the bone marrow to travel in the bloodstream to the heart and repair blood vessels and muscle cells. Treadmill exercise testing: Patients exercise on a treadmill with continuous monitoring of the heartbeat and frequent measurements of oxygen saturation, using a finger clip device. The patient continues to exercise until moderate chest pain, shortness of breath, or fatigue develops. Questionnaire: Patients fill out a 15-minute questionnaire about their general physical and mental health status at the first and last visits to the clinic. Magnetic resonance imaging (MRI) of the heart: Patients who are eligible to undergo MRI have this test twice during the study, once before beginning the rehabilitation program and again after completing the program. The MRI shows heart function and blood flow in the heart. For this test, the patient lies on a stretcher inside a long narrow cylinder (the scanner). During the scan, the drug dipyridamole, which increases blood flow to the heart, is infused into a vein of the hand or arm. Another drug, gadolinium, is also infused to brighten the images produced.

This study is a randomized open label study that implies the administration of asprin according to three different regimens. The aims of the study are: to establish whether coronary artery bypass surgery and / or aortic valve replacement surgery with bioprostheses is associated with changes in the rate of platelet regeneration that can reduce the effectiveness of aspirin administered at a dose of 100mg/die in terms of inhibition of platelet biosynthesis of thromboxane A2. to determine whether these patients need a different (shorter) interval of administration in order to completely and permanently inhibit the platelet COX-1. The endpoints of this study are: - To evaluate the changes in the levels of TXB2 and 12-HETE in serum at 12 and 24 hours after administration of aspirin and the changes in the levels of 11-dehydro TXB2 urinary 8-iso-PGF2 alpha urinary, 2-3 dinor-6-chetoPGF1 alpha, Verify-NOW Aspirin, platelets crosslinked at 12 and 24 hours after administration of aspirin

Background: - Heart disease is the leading cause of death in the United States. Eating fruits and vegetables with chemicals called flavonoids may protect against heart disease and improve blood flow to the heart. They are found in blackcurrant berries. Oils found in fish and mussels called omega-3 fats have also been shown to protect the heart. Researchers want to know if blackcurrant extract and omega-3 fats can improve blood flow, which may increase blood to the heart. They also want to learn about the health of blood vessels and how the heart works. Objective: - To learn if blackcurrant extract and omega-3 fats will improve blood flow and make the heart beat stronger. Eligibility: - Healthy adults 55 to 75 years old. Design: Participants will be screened with medical history, physical exam, and blood tests. Visit 1 will take 6 7 hours. Participants will have physical exam and blood and urine tests. A small device like a microphone will be placed on their arm to take pictures of blood vessels. A blood pressure cuff will be tightened on their arm and more pictures will be taken. Blood pressure cuffs will be placed on their arms and legs. They will be tightened at the same time and blood pressure will be measured. Participants will answer questions about their eating and exercise. Every 8 weeks, participants switch from taking blackcurrant and/or omega-3 tablets to a placebo to no tablets. <TAB> Every 8 weeks, they will have another shorter clinic visit that will repeat most of visit 1.