Active clinical trials for "Ischemia"

Acute ischemic stroke affects roughly 1 in 50,000 children every year and is one of the top ten causes of death in children. Currently, caregivers lay the affected child flat in hopes of increasing blood flow to the brain and reducing the volume of the brain which is damaged. However, there are currently no techniques to measure brain blood flow at the child's bedside and indicate if this treatment is effective. We will probe brain blood volume, oxygen saturation, and flow with red light to determine the efficacy of this intervention.

The objectives of the PMS are to observe the frequency, type, and degree of device deficiency to assure the safety of the new medical device (XIENCE PRIME) as well as to collect information on evaluation of the efficacy and safety for reevaluation.

Digestive tract is supposed to be the motor of multiple organ failure. In ICU patients, mesenteric ischemia appears even when macrocirculatory parameters are controlled especially in our experience in patients coming in ICU after a cardiac surgery. The investigators suppose that microcirculatory failure develops and results in suffering of non major organs like muscle, skin and digestive tracts. In this study the investigators monitor digestive tract with plasmatic IFABP dosage and microcirculatory circulation with NIRS during a VOT and plasma glycocalyx measurements. The population is composed by patients having coronary artery bypass during cardiopulmonary bypass. The first aim of this study is to show that digestive tract is suffering with the use of extracorporeal circulation and will be assessed with Plasmatic Intestinal Fatty Acid Binding Protein when IFABP will more than 300 pg/ml ; and with citrullinemia when citrullinemia will be less than 20 micromol/L. The second aim is to investigate link between endothelial dysfunction and digestive tract. Endothelial dysfunction is assessed with tissular oxygen saturation before, during and after a vascular occlusion test of 3 minutes (measurement of basal value, desaturation curve, resaturation curve and hyperemic response by measurement of area under curve). Endothelial glycocalyx and NO pathway will be investigate (see under) Our objective is to enroll 100 patients. The same study will be done in a group of patients who benefit from coronary artery bypass without extracorporeal circulation to see the effects of extracorporeal circulation support.

The purpose of this study is to evaluate the efficacy of nicorandil in the achievement of maximal coronary hyperemia compared with adenosine.

CORONARY ARTERY DISEASE AND THE BENEFIT OF BYPASSES Despite considerable advances in medicine, cardiovascular diseases remain the number one cause of death globally. In industrialized countries, coronary artery disease (CAD) is the leading cause of death, consequence of myocardial infarction (MI). Artificial - or natural - bypasses exert a protective effect by providing an alternative source of blood flow to a myocardial territory potentially affected by an acute coronary occlusion. Coronary collaterals represent pre-existing inter-arterial anastomoses and as such are the natural counter-part of surgically created bypasses. In patients with chronic CAD, sufficient coronary collaterals have been shown to confer a significant benefits in terms of overall mortality and cardiovascular events. EXTRACARDIAC-TO-CORONARY COLLATERAL SUPPLY Commonly, coronary collaterals are implicitly understood to exist between coronary artery branches. However, the structural existence of coronary collaterals with an extracardiac connection has been confirmed by anatomical investigations. Pathophysiologically and with regard to a potential for arteriogenic stimulation, the connections from the internal mammary arteries, are of special interest. In a recently published work the investigators have investigated the effect of temporary balloon occlusion of the distal IMA on coronary collateral function. There were equivocal findings for the left circumflex coronary artery: CFI was increased by ipsilateral IMA occlusion, but the level of myocardial ischemia was unchanged. MYOCARDIAL STEAL VIA INTERNAL MAMMARY ARTERIES In the investigators' previous study, the coronary occlusion with simultaneous distal IMA occlusion was always performed first as a conservative measure against false-positive detection of internal-mammary-to-coronary artery connections. Repetitive coronary occlusions per se result in higher collateral flow by collateral recruitment and reduced ischemia by ischemic preconditioning and augmented collateral function. Conversely, the sensitivity of the employed method was reduced and might have contributed to the equivocal findings in case of the left circumflex artery. Moreover, the hypothesize d mechanism of localized pressure augmentation was not investigated. This study aims to further characterize the prevalence and function of natural ipsilateral IMA-to-coronary connections, as well as to investigate the hemodynamic mechanisms of coronary collateral function augmentation by distal IMA occlusion. In the investigators' last study, the increased coronary collateral function in response to manipulation of a potential coronary collateral donor (in this case, the IMA) was taken as indirect evidence for the existence of IMA-to-coronary-artery connections. Thus, the employed distal IMA occlusion served as a positive stimulus. Conceptually, additional evaluation with a negative stimulus could heighten the discriminatory power of the investigation. This could be in the form of a hyperemic stimulus affecting the collateral donor, ie in analogy to myocardial or coronary steal (ie, a reduction in coronary collateral supply to a collateral recipient).

Stroke affects over 125,000 people each year in the UK and leaves at least 50% disabled. Treatment of stroke caused by a blockage in a blood vessel (ischaemic stroke), with clotbusting drugs improves the chances of good recovery, but must be given within 4.5 hours of onset. Currently only a small proportion of patients who arrive in hospital within 4.5 hours are treated. This is largely due to uncertainty about diagnosis and concerns about risk of bleeding associated with clotbusting medication. Patients with mild or improving symptoms in particular are often not treated because of uncertainty about relative risks and benefits. However, around one third of these patients go on to be significantly disabled. Routine CT scanning often does not show abnormalities in acute stroke (which take hours to become easily visible), and cannot show the extent or severity of blood flow changes in ischemic stroke. We wish to investigate the value of additional CT scanning that gives information on the blood vessels (angiography, CTA) and blood flow to the brain (perfusion, CTP) by undertaking a randomised trial. Extra scans are done in the same scanner and involve some extra radiation, injections of a contrast dye, and some extra time to acquire process and interpret. The extra scans may allow better treatment decisions for patients by increasing diagnostic certainty and by better assessment of stroke severity. However, we do not know whether the potential gains from better selection justify the resources and potential treatment delays that are involved. We will investigate whether the proportion of patients given clotbusting drugs differs between the two scanning protocols; and whether the outcomes differ, using standard measures of disability. We will also investigate whether use of different scanner manufacturers' software affect interpretation of scans.

intravenous rt-PA is effective to reduce the risk of death or dependency after ischaemic stroke. This effect is due to an early recanalization secondary to the lysis of the clot. However this effect may be counterbalanced by the increased risk of bleeding and also the neurotoxicity of rt-PA, which has been shown in animals to depend on the ratio single chain (sc) / double chain (tc) in the rt-PA administered. The main objective of OPHELIE is to determine whether the functional outcome after treatment by iv rt-PA depends on the ratio sc-rtPA / tc-rtPA. Secondary objectives were to identify the influence on the risk of brain haemorrhage, and the influence of the cognitive state (OPHELIE-COG substudy).

The aim of the investigators was to determine whether the immediate management of any detected sleep disorders can improve outcomes in patients who have had a transient ischemic attack (TIA) or minor stroke. This group of patients is at high risk for having a recurrent stroke or TIA, and the investigators would like to investigate new ways of preventing potentially avoidable events. The treatment of sleep disorders immediately after a stroke or TIA may prove to be a novel method of avoiding future strokes and improving outcomes.

The purpose of this study is to determine whether remote ischemic preconditioning with postconditioning (RIPC+RIPostC) reduces myocardial injury and improves clinical outcomes in heart transplantation surgery.

The purpose of this study is determine the diagnostic performance of dual energy computed tomography perfusion for non-invasive assessment of the hemodynamic significance of coronary stenosis, as compared to a direct measurement of fraction flow reserve during cardiac catheterization as a reference standard. The overall objective of the present study is to determine the diagnostic performance of dual energy computed tomography perfusion for non-invasive assessment of the hemodynamic significance of coronary stenosis, as compared to direct measurement of fraction flow reserve during cardiac catheterization as a reference standard.