Active clinical trials for "Ischemia"

Patients with stroke or transient ischemic attach should receive advise on smoking cessation. It is however unknown if an intensive smoking cessation program is better than ordinary advise on smoking cessation during hospitalisation for stroke or transient ischemic attack. The aim of the study was to assess if an intensive smoking cessation program made more patients stop smoking after stroke or transient ischemic attack.

The lack of blood flow to the small intestine causes mesenteric ischemia. Using a Superconducting QUantum Interference Device (SQUID) which measures the magnetic field of the small intestine, we are hoping to identify abnormalities without surgical intervention.

To continue a registry of World War II veteran twins maintained by the National Academy of Sciences-National Research Council (NAS-NRC).

To examine the relationships among psychosocial factors and carotid atherosclerosis, myocardial ischemia, arrhythmias, and thrombosis.

This study will use magnetic resonance imaging (MRI) to determine if silent strokes occur during angioplasty of the blood vessels in the neck or skull. Neck and skull angioplasties are relatively new procedures whose possible complications are still under investigation. Patients 18 years of age or older who are admitted to Suburban Hospital in Bethesda, Maryland, for angioplasty of one or more of the blood vessels in the neck or skull may participate in this study. Participants must be able to undergo a brain MRI. Within 24 hours before their angioplasty, patients will provide a medical history and have a physical examination and brain MRI. The physical examination and MRI will be repeated within 24 hours after the angioplasty. MRI is a diagnostic test that uses a magnetic field and radio waves to show structural and chemical changes in tissues. This technique is more sensitive than X-rays in detecting some changes that occur in diseases of the brain. For the procedure, the patient lies on a table that slides into a metal cylinder (the scanner). The confined space may produce anxiety in some patients, and patients can talk to the technician at all times during the procedure. Earplugs are provided to muffle loud knocking and pulsing noises that occur while the scanner is taking pictures. During the study, the contrast material gadolinium may be injected into an arm vein. Gadolinium "brightens" the pictures, producing better images of brain blood flow. Patients will be contacted by telephone 30 days after the procedure to follow how they are doing and learn whether any complications resulted from the angioplasty.

The goal of this qualitative study is to explore the experiences of patients who have been diagnosed with chronic limb-threatening ischaemia (CLTI). The main questions it aims to answer are: What are the perceptions and experiences of patients between first symptom of CLTI and vascular surgery assessment What is important to patients during this process. Participants will be interviewed and their words analysed using reflexive thematic analysis.

This series aims at studying the peripapillary and macular vascular changes in subjects with unilateral anterior ischemic optic neuropathy via Optical Coherence Tomography Angiography (OCTA).

Peripheral artery disease is a worldwide problem, leading to high mortality and mobility. Critical limb ischemia (CLI) is associated with high risk of amputation with the subsequent decreased in life quality. Endovascular therapy is now considered the primary treatment option in these patients to improve the vascularity and prevent amputations. In recent years, development of molecular imaging tools are now become available. A recent radio tracer named 18F-Fluoroazomycin Arabinoside (FAZA) its an specific marker of hypoxia in the tissues and has been used in multiples studies. This tracer can be used in PET/MR scan providing a potentially power diagnostic tool in patients with CLI, allowing in one diagnostic study the evaluation of location and degree of hypoxia in the extremity tissues. This diagnostic tool may offer a better assessment pre and post standard of care endovascular treatment for the patients. Moreover, some of the patients treated with endovascular therapy may not have a favorable outcome, without a clear reason explaining this situation. We will try to find some predictor model in the FAZA PET/MR that can explain the different outcomes and may help clinicians choose the best treatment option in specific cases. Thirdly, post processing for optimization of the MR sequences in patients with CLI will be performed at the MR component of the PET. There would thus be great clinical interest in developing non-invasive tools that could provide more accurate diagnostic information compared to traditional tests for these patients population.

The identification of abnormal narrowing of a blood vessel from non-invasive coronary angiography remains an exciting goal. While Computed Tomography (CT) has established a clear role in patients it retains some limitations. Primarily, alterations in blood flow leading to a restriction in blood supply to tissues cannot be accurately predicted from the anatomical assessment of an abnormal narrowing in a blood vessel - a limitation of both invasive, and computed tomographic, angiography. This is important, as there is now a raft of evidence demonstrating that revascularisation should only be considered in the presence of a restriction in blood supply to tissues. The gold standard method of identifying a restriction in blood supply to tissues is measurement of the fractional flow reserve (FFR), a dimensionless value generated as a ratio between the circulatory pressure before and after a narrowing of a blood vessel. At present, patients with indeterminately significant abnormal narrowing in a blood vessel identified using CT must go on to have a further test for a restriction in blood supply to tissues, prior to any decision about revascularisation being made. As part of our governance commitment to maintaining our reporting standards, we undertake ongoing audit of our cardiac CT practice. The investigators recently identified a group of patients who have undergone FFR measurement as part of routine clinical care, and compared these to our clinical reports, to ensure that appropriate recommendations were being made. It appeared that the ability to predict important abnormal narrowing in a blood vessel was reasonable (~70%) and hence we propose the formulation of a research question to explore this further. The primary objective of this study is to determine the accuracy of a visual assessment of the likely significance on blood flow of a narrowing of a blood vessel identified on cardiac CT, in comparison to invasive, fractional flow reserve. The secondary objective is to evaluate features of an abnormal narrowing in a blood vessel that is likely to have a significant impact on blood flow. The investigators' working hypothesis is that cardiac CT FFR is a useful predictor of abnormal narrowing in a blood vessel.

Critical Limb Ischemia (CLI) is defined as limb pain that occurs at rest, or impending limb loss that is caused by severe compromise of blood flow to the affected extremity. CLI is a major cause of death and disability (secondary to myocardial infarction, stroke and amputation). The mortality in patients with CLI approaches 25% and 50% at one and five years respectively. High on-treatment platelet reactivity (HPR) in patients treated with aspirin and clopidogrel (previously referred to as "resistance") is associated with an increased risk of recurrent cardiovascular events after percutaneous coronary interventions and acute coronary syndromes. The prevalence and significance of High on-treatment Platelet Reactivity (HPR) in patients with critical limb ischemia treated with aspirin and/or clopidogrel is not known. The investigators project aims to investigate the prevalence of HPR (to aspirin and clopidogrel) in one hundred patients with diagnosis of critical limb ischemia encountered at University of Southern California (USC) affiliated hospitals (Los Angeles County Hospital and Keck Hospital of University of Southern California).