Clinical Trials

This study is testing whether a medicine called metformin can help treat aortic aneurisms in the abdomen. The study will use imaging tests to examine whether metformin can help prevent these aortic aneurisms from getting bigger. To participate in this study, you must be 55 to 90 years old and diagnosed with an abdominal aortic aneurism. This study takes place in Stanford, California.

Do you have heart disease that requires an ICD to prevent sudden cardiac arrest? This study aims to learn what signs distinguish patients who have a higher risk of an arrhythmia that leads to sudden cardiac arrest. Researchers plan to track patients with a recent ICD replacement for 10 years. To participate in this study, you must be between 18 and 85 years old. This study is located in Washington, D.C.; Baltimore, Maryland; and Richmond, Virginia.

The study is to investigate that the worsening orthostatic tachycardia and symptoms after glucose ingestion in POTS patients are due to a greater increase in splanchnic venous capacitance and excessive blood pooling during an orthostatic challenge.

The purpose of this study is to determine the occurrence of scarring of the heart (cardiac fibrosis) and inflammation in those with perinatally acquired Human Immunodeficiency Virus (HIV) infection compared to people not infected with HIV. The information learned from this research may help the investigator to better understand the link between cardiac fibrosis and cardiac dysfunction and inflammation in those with perinatally acquired HIV infection compared to the uninfected.

Do you have heart disease? This study is looking to improve the quality of heart CT scans by using new methods to create the images. You may be able to participate in the study if you are 18 years old or older, have heart disease, and have been told by your doctor that you need a CT scan. This study is taking place at the National Institutes of Health Clinical Center in Bethesda, Maryland.

Do you have a high-risk pregnancy? This study will investigate the use of a non-invasive scan called fetal magnetocardiography to detect potential problems in the fetus in five high-risk pregnancy conditions associated with stillbirth. The scan is normally used to look at fetal heart rhythms. To participate in this study, you must be at least 18 years old and pregnant with one of the following: having a stillbirth in a previous pregnancy, carrying identical twins, or having a fetus that has been diagnosed with major congenital heart disease, fetal hydrops, or fetal gastroschisis. This study takes place in Madison and Milwaukee, Wisconsin.

Are you a woman who is postmenopausal or a man older than 65? This study will investigate the effects of oral progesterone for older women and testosterone for older men on QT intervals. QT intervals that are increased by medicine can lead to dangerous heart rhythm problems. Researchers hope to learn more about why this happens and how to deliver safer doses. This study is located in Indianapolis, Indiana.

his trial will evaluate an oral drug discovered in a high throughput screen, which increases fetal globin protein (HbF and red blood cells expressing HbF)and messenger ribonucleic acid (mRNA) to high levels in anemic nonhuman primates and in transgenic mice.

Sickle Cell Disease (SCD) impairs oxygen transport to tissue and causes endothelial injury. Thus, therapeutic interventions aim to improve both, but there is an unmet need for biomarkers to determine when intervention is necessary and evaluate the effectiveness of the chosen intervention in individual patients. This study proposes to monitor SCD and its treatment through their impact on cerebral hemodynamics, as the brain is one of the most vulnerable and consequential targets of the disease. Specifically, this study will optimize quantitative magnetic resonance imaging (MRI) and advanced optical spectroscopy techniques such as frequency-domain near-infrared and diffuse correlation spectroscopies (FDNIRS-DCS) to monitor 1) cerebral oxygen transport with measures of cerebral blood flow (CBF), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen consumption (CMRO2) and 2) endothelial function with cerebrovascular reactivity (CVR).

The main goal of this study is to determine whether the treatment will lead to a complete absence of severe vaso-occlusive events (VOEs) in patients with severe SCD.