View clinical trials related to Ischemia.
Filter by:Coronary artery disease (CAD) is the leading cause of death worldwide. Patients with severe CAD are often treated with coronary artery bypass grafting (CABG). Novel treatment strategies need to be pursued to respond to the continuous increase in the risk profile of contemporary CABG patients. Surgical myocardial revascularization is commonly performed with the use of cardiopulmonary bypass (CPB). Neurological impairment following CABG may take on the form of a new-onset motor deficit or postoperative cognitive dysfunction. The former is rare, but potentially devastating. Conversely, declines in attention, memory and fine motor skills can frequently be documented. Ischemic preconditioning is a phenomenon of an endogenous protective response to organ ischemia, which is triggered by brief cycles of nonlethal ischemia and reperfusion in tissues known to be more resistant to ischemic insults. In clinical practice remote ischemic preconditioning (RIPC) is achieved by inflicting short periods of ischemia with intermittent restitution of flow to the upper extremity. This intervention has been shown to be effective in the reduction of myocardial injury in cardiac surgical patients. The hypothesis tested in this research proposal is that RIPC will decrease the extent of postoperative neurological injury following CABG. In this research project, 70 patients scheduled for an elective CABG will be recruited at a single center. They will be randomly allocated to either undergo RIPC (intervention arm) or a sham procedure (control arm). Inflating a blood pressure cuff to 200 mmHg for 5 min will induce RIPC, thereby inducing a brief period of ischemia. This will be followed by a 5-minute arm reperfusion. In total, three cycles of arm ischemia and reperfusion will be induced in this fashion. All patients will undergo pre- and post-procedural magnetic resonance imaging (MRI) of the brain, as well as neurocognitive testing. The array of MRI tools that will be used for the quantification of brain injury will include fluid attenuated inversion recovery, diffusion weighted and susceptibility weighted imaging, coupled with resting state functional MRI. The investigators aim to determine whether RIPC can reduce the adverse impact of CPB on neurological outcome as evaluated by MRI detectable brain ischemia and neurocognition.
Specific cardiovascular diseases, such as stroke and heart attack, have been shown to vary by ethnic group. However, less is known about differences between ethnic groups and a wider range of cardiovascular diseases. This study will examine differences between ethnic groups (White, Black, South Asian and Mixed/Other) and first lifetime presentation of twelve different cardiovascular diseases. This information may help to predict the onset of cardiovascular diseases and inform disease prevention strategies. The hypothesis is that different ethnic groups have differing associations with the range of cardiovascular diseases studied.
The study seeks to determine the accuracy of using anatomic and physiologic information measurable by computed tomography features of stenosis, plaque, fractional flow reserve-CT and to compare this measure to stress testing for the detection of myocardial ischemia against the gold standard of cardiac catheterization with fractional flow reserve. The hypothesis of this proposal is that integrating anatomic plaque features with physiologic fractional flow reserve-CT will optimize identification of coronary lesions that are ischemia-causing by computed tomography .
Previous studies in animals and humans has shown that brief periods of reduced blood flow to one organ or tissue in the body can help protect other tissues from subsequent injury caused by reduced blood flow such as a stroke. This phenomenon is known as remote ischemic preconditioning and may help protect brain cells after a stroke. The investigators are studying a specific stroke type called subcortical stroke that is very common and has a high rate of recurrent stroke and cognition problems despite intensive prevention measures.
Remote ischemia precondition could protect the liver from ischemia reperfusion injury in patients undergoing hepatectomy.
This study will compare two ways of treatment for acute ischemic stroke: an endovascular treatment (EVT), defined as intraarterial thrombolysis and/or mechanical thrombectomy as a first choice treatment versus intravenous thrombolytic therapy (IVT) only or followed by EVT in patients with acute ischemic stroke due to a main brain artery occlusion within 4.5 hours after onset. Patients treated with IVT only or with IVT followed by EVT will be analyzed separately.
Among the current myocardial CT perfusion techniques, dynamic CT perfusion technique is most advantageous in obtaining information on myocardial blood flow and volume. However, dynamic CT perfusion technique involves higher radiation dose than static CT techniques. Patients have to take a breath hold during 30 seconds with current dynamic CT perfusion protocol. If patients cannot hold their breath, anterior or inferior myocardium might be excluded due to limited scan coverage of a 128-slice dual-source CT scanner. Reduction of scanning duration of dynamic CT perfusion may not only reduce radiation exposure, but also make patients more comfortable. Therefore, the investigators intended to propose a modified scan protocol with shorter scan duration and compare diagnostic accuracy of a modified scan protocol with the current scan protocol.
Vascular endothelial growth factor (VEGF) and Endostatin (ES) participate angiogenesis after cerebral ischemia. Circulating endothelial progenitor cells (EPCs) also play a crucial role in neovascularization and tissue repair after acute ischemic stroke (AIS). The investigators sought to compare the expression of VEGF and ES in serum and the circulating EPCs in patients after AIS with that of healthy control subjects. The investigators obtained peripheral blood and serum samples from study subjects. EPCs in blood samples from AIS patients and healthy controls were quantified by flow cytometry 1 day, 3 days, 5 days and 7 days after AIS. VEGF and ES were measured by enzyme linked immunosorbent assay at the same time points. The relation between them and the relation of them to prognosis of such patients with acute ischemic stroke were assessed.
Patients after ischemic stroke are at high risk of recurrent cardiovascular events and of developing post-stroke complications. There is a substantial gap between risk factor management in real life and that recommended by international guidelines. Stroke Card is a multifaceted comprehensive post-stroke disease management program to detect and treat complications and optimize secondary prevention. The investigators hypothesize that, compared to standard care, Stroke Card will lead to an at least 33.3% risk reduction in recurrent cardiovascular events and improve health-related quality-of-life.
Purpose 1. To validate 2 -day loop recording ( R.Test Evolution 4 ) to 2 -day Holter recording (gold standard) for the detection of atrial fibrillation of ≥ 30 seconds duration in a consecutive population of patients with stroke or transient ischemic attack (TIA). 2. To determine whether short run of atrial fibrillation (< 30s ) or the presence of many supraventricular extrasystoles detected on Holter recording, is associated with risk of re-stroke in a consecutive population of patients with stroke or TIA . 3. To test whether a 7-day Loop Recording (R -test) detects more patients with atrial fibrillation than 2 days of Holter recording in a consecutive population of patients with stroke or TIA.