Active clinical trials for "Ischemia"

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 purpose of this study is to study the demographic,laboratory,endoscopic, and outcomes of ischemic colitis patient presented with severe lower gastrointestinal bleeding compared to other diagnoses.

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).

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).

The aim of the SURVIBIO study is to characterize accurate biomarkers for acute mesenteric ischemia, in particular at early stages. In the study, the development of biomarkers will be based on the analysis of human biological samples from patients and controls that will be conserved in a biological library. Samples will be analysed in the Laboratory for Vascular Translational Sciences (LVTS, Inserm U1148), in the Department of Biochemistry (Pr Puy, Dr Peoc'h), in Paris V university , in Imperial College of London (Pr Dumas), in Jacques Monod Institute and in Maastricht University Medical Center . The candidate markers will be determined according to an a priori method (form markers already described in the literature) and with no a priori strategy using -omics methods.

Recent evidence of a potential role for cardiac progenitor cells (CPCs) in cardiac repair and the discovery of a vasoprotective axis of the renin-angiotensin system (RAS) offer such breakthroughs. Investigators have observed that an imbalance in the vasoprotective axis {angiotensin converting enzyme 2 (ACE2)/angiotensin-(1-7) [Ang-(1-7)]/Mas receptor} and the vasodeleterious axis [angiotensin converting enzyme (ACE)/angiotensin II (AngII)/AngII type 1 receptor (AT1R)] of the RAS within the CPCs affects their functionality and regenerative potential. Investigators believe that restoring the balance between these two axes of the RAS is essential to improve CPC function and enhance their reparative capabilities. These observations have led to the hypothesis that genetic modification of CPCs by overexpression of ACE2/Ang-(1-7) will enhance their reparative function and improve their potential to attenuate myocardial ischemia-induced cardiac damage.

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.