View clinical trials related to Ischemia.
Filter by:Coronary artery computed tomographic angiography (CTA) is a widely used, highly accurate technique for the detection of coronary artery disease (CAD), with sensitivity and negative predictive values of over 90% (1-4). Patients with normal CTA findings have an excellent prognosis and do not require further testing for CAD (5). However, like invasive coronary angiography (QCA), CTA is an anatomic test and, unless lesions are very severe (>90% stenosis), cannot reliably predict the impairment of flow (functional significance) of intermediate grade stenoses. For this reason, in approximately 15-25% of patients, additional functional testing may be required after CTA, usually in the form of stress testing (6-8). Stress testing is commonly done by exercise or pharmacologic stress with electrocardiographic monitoring and often, imaging of myocardial perfusion by nuclear scintigraphy (MPI) or detection of abnormal contraction by echocardiography. This requires a separate procedure, entailing time, expense and limited risk. Furthermore, in patients with previously known CAD, CTA alone is not an adequate test, because in most cases there are multiple lesions that are possible sources of ischemia. Over the last 10 years, these investigators and others around the world have developed a method of imaging myocardial perfusion by CT (CTP). This test is an adjunct to the usual Cardiac Computed Tomography Angiography (CCTA) procedure and can be done immediately thereafter, using conventional pharmacologic stress agents. It has demonstrated accuracy in many single center trials, and in this large multicenter study, the CORE320 trial (9,10) which showed a high accuracy in predicting the combined results of QCA plus MPI testing and a second multicenter trial established non-inferiority of myocardial CTP compared with nuclear stress testing (11,12). Additionally, this investigator group has published a direct comparison of diagnostic performance of myocardial CTP imaging and SPECT myocardial perfusion imaging and demonstrated superior diagnostic performance of CTP imaging compared with SPECT for the diagnosis of significant disease on invasive angiography (13). CTP images can be acquired with two different approaches: static or dynamic. In the CORE320 study, the CTP protocol used static acquisition method. The static CTP method, samples a snapshot of the iodine distribution in the blood pool and the myocardium over a short period of time, targeting either the upslope or the peak of contrast bolus. The notion behind this is that, at the upslope of the contrast, the difference in attenuation value of the ischemic and remote myocardium is at the maximum which enables for qualitative and semi-quantitative assessment of myocardial perfusion defects. The static CTP, however, does not allow for direct quantification of the myocardial blood flow (MBF). One of the drawbacks of static CTP lies in the acquirement of only one sample of data and the possibility of mistiming of the contrast bolus that results in poor contrast-to-tissue ratios by missing the peak attenuation (14). Output and flow rate of the contrast material may affect bolus timing. In addition, the acquisition of data from sequential heartbeats affects the attenuation gradient and may result in a heterogeneous iodine distribution, mimicking perfusion defects (15). Furthermore, the static CTP is limited in detection of balanced ischemia, where the perfusion of the entire myocardium is impaired and therefore there is no reference remote myocardium for comparison for semi-quantitative or qualitative static methods of CTP interpretation. Dynamic CT perfusion imaging uses serial imaging over time to record the kinetics of iodinated contrast in the arterial blood pool and myocardium. This technique allows for multiple sampling of the myocardium and the blood pool and creating time attenuation curves (TAC) by measuring the change in CT attenuation over time. Mathematical modelling of TACs permits for direct quantification of MBF. Despite its advantages, the use of dynamic CTP were limited in the past. A high temporal resolution and high number of detectors are required for dynamic CTP to allow for entire myocardial coverage, and in order to obtain multiple consecutive images at high heart rates(16,17). But the main challenge of dynamic CTP acquisition was the high radiation dose associated with this technique. Nevertheless, with the introduction of the cutting-edge 320 detector CT scanning systems with fast gantry rotation the issue of the cardiac coverage is eliminated(17). The second-generation 320-row scanners also permit the quantification of the MBF with dynamic CTP acquisition with relatively low-dose of radiation(18,19). In this study the investigators aim to evaluate the feasibility, safety and accuracy of the low-radiation dose dynamic myocardial CT perfusion compared to static CTP approach to detect hemodynamically significant coronary artery disease.
The objective of this post-market study is to evaluate the safety and effectiveness of the LimFlow System in creating a below-the-knee arterio-venous fistula for venous arterialization in subjects with critical limb ischemia.
This is a pilot randomized control trial (RCT) to explore the possible beneficial effect of a novel combination therapy consisting of molecular hydrogen H2 plus minocycline ("H2M"), on neurological recovery after acute ischemic stroke.
Soluble epoxide hydrolase (sEH) is the metabolizing enzyme of epoxyeicosatrienoic acids (EETs), which may play a role in reducing neuroinflammation and regulating cerebral blood flow after subarachnoid hemorrhage (SAH). Hypotheses: Pharmacologic inhibition of the sEH enzyme is safe and will result in increased EETs availability in the blood and cerebrospinal fluid. This study is a double-blind, placebo-controlled, phase 1b randomized trial to evaluate the safety and efficacy of GSK2256294, a novel soluble epoxide hydrolase inhibitor in patients with aneurysmal SAH.
Hyperglycemia is present in 50 percent of patients with acute ischemic stroke. Patients with hyperglycemia have higher in hospital, 30 and 90 day mortality and morbidity. Sixty percent of these patients have some form of diabetic syndrome, known or unknown. Remaining 40% of patients are not diabetic. Contrary to logic patients with non diabetic hyperglycemia (NDH) have statistically higher morbidity and mortality compared to the diabetic hyperglycemia (DH) cohort. So far multiple treatment trials (THIS, GRASP, GIST-UK, SHINE ongoing) with differing treatment goals have shown no clear benefit, however no obvious distinction was made along the diabetic and non-diabetic hyperglycemic groups. If hyperglycemia in the acute phase was the only culprit in worsening the injury, then there should be no difference in the outcomes for DH and NDH. Existing data implies that the two categories are two distinct physiological entities that are thus not amenable to same treatment. Stating it simply NDH is not an insulin deficient state where as DH is. Alternative possibility is that body and Neurons are accustomed to high sugars in diabetics and thus can tolerate higher sugars better during ischemic stroke compared to non diabetics. The overarching hypothesis is that reducing blood sugars in NDH increases stroke volume and thus consequently worsens outcome.
The purpose of the study is to evaluate the hypothesis that patients receiving remote ischemic conditioning using the autoRIC device show statistically significant reduction in the prevalence of ischemia-reperfusion injury to the myocardium as compared to patients in the autoRIC Sham device arm (within 12-24 hours post non-emergent PCI with stent implantation).
The Stroke Recovery Initiative is a nation-wide participant recruitment registry that connects people who have had a stroke with researchers who are working to develop new approaches to improve recovery after stroke.
The first aim of this study is to investigate the frequency and severity of a specific pathological metabolic pattern, mitochondrial dysfunction, of the brain in comatose patients under neurocritical care. This pattern is recognized as a complication after compromised blood flow to the brain and may be amenable to treatment. The other main aim of this study is to correlate patterns of metabolites between brain and jugular venous blood. It is probable but not proven that jugular venous microdialysis can mirror the global metabolic state of the brain.
The purpose of this study is to evaluate whether Thromboelastography (TEG) parameters on admission might be predictive for early neurological deterioration in acute ischemic stroke patients, specifically for the DWI lesion evolution within the first week after stroke onset.
This is a prospective, non-randomized, open label, multi-center study including 60 patients with symptomatic ischemic heart disease with 70%-100% coronary artery stenoses and occlusions enrolled and treated in this investigational device study.