View clinical trials related to Reperfusion Injury.
Filter by:Heart failure (HF) is an enormous health burden affecting approximately 5.1 million people in the US and is the cause of 250,000 deaths each year. Approximately 50% of HF is caused by myocardial ischemia and requires immediate restoration of coronary blood flow to the affected myocardium. However, the success of reperfusion is partly limited by intramyocardial hemorrhage, which is the deposition of intravascular material into the myocardium. Hemorrhagic reperfusion injury has high prevalence and patients have a much greater risk of adverse left ventricular remodeling, risk of fatal arrhythmia, impaired systolic function and are hospitalized at a greater rate. Recent magnetic resonance imaging techniques have improved assessment of reperfusion injury, however, the association between MRI contrasts and reperfusion injury is highly unclear, and lacks specificity to IMH. Improved imaging of IMH and accurate knowledge about its spatial and temporal evolution may be essential for delivery of optimal medical therapy in patients and critical to identify patients most at risk for adverse ventricular remodeling. The overall goal is to investigate the magnetic properties of hemorrhage and develop MRI techniques with improved specificity to hemorrhage. New MRI techniques permit noninvasive assessment of the magnetic susceptibility of tissues and can target tissue iron. Therefore, the investigators hypothesize that MRI imaging of myocardial magnetic susceptibility can map hemorrhagic myocardium. The investigators will perform a longitudinal observational study in patients after reperfusion injury to validate these methods, compare the methods with conventional MR contrasts and develop MR methods for imaging humans.
This a prospective observational study including patients with ST-segment elevation myocardial infarction undergoing cardiovascular magnetic resonance for clinical reason during the index hospitalization. This local registry stemmed from multi-center european registry on cardiovascular magnetic resonance
Ischemia/reperfusion injury following aortic cross-clamping for vascular surgery leads to systemic hemodynamic and microcirculatory perturbances. The use of different anesthetic regimens may have an impact on tissue perfusion. The aim of this study was to explore changes in microvascular perfusion in patients undergoing elective open abdominal aortic aneurysm repair under balanced or total intravenous anesthesia. Prospective observational study on 40 patients scheduled for elective open infrarenal abdominal aortic aneurysm repair, who received balanced (desflurane + remifentanil, n=20) or total intravenous anesthesia (TIVA, propofol + remifentanil using target-controlled infusion, n=20) according to the clinician's decision. A goal-directed hemodynamic management was applied in all patients. Hemodynamics and arterial/venous blood gases were compared before anesthesia induction (baseline) and at end-surgery. Changes in sublingual microvascular flow and density were assessed with incident dark field illumination imaging. Near infrared spectroscopy was applied on the thenar eminence with a vascular occlusion test (VOT) to assess variations in the peripheral muscle tissue oxygenation and microcirculatory reactivity.
This prospective randomized study elucidates the effects of exogenous nitric oxide delivered to the extracorporeal circulation circuit for cardioprotection against ischemia-reperfusion injury during coronary artery bypass graft surgery with cardiopulmonary bypass.
The application of tourniquet is indispensable for a bloodless surgical area in total knee arthroplasty surgery. The release of tourniquet produces reactive oxygen species which can cause injury and then ischemia-reperfusion injury emerge. Our aim in this study is to investigate effects of pregabalin, GABA analog drug, on the tourniquet induced ischemia-reperfusion injury.
In acute myocardial infarction, early restoration of epicardial and myocardial blood flow is of paramount importance to limit infarction size and create optimum conditions for favourable long-term outcome. Currently, restoration of epicardial blood flow is preferably and effectively obtained by primary percutaneous coronary intervention (PPCI). After opening the occluded artery, however, the reperfusion process itself causes damage to the myocardium, the so called "reperfusion injury". The phenomenon of reperfusion injury is incompletely understood and currently there is no established therapy for preventing it. Contributory factors are intramyocardial edema with compression of the microvasculature, oxidative stress, calcium overload, mitochondrial transition pore opening, micro embolization, neutrophil plugging and hyper contracture. This results in myocardial stunning, reperfusion arrhythmias and ongoing myocardial necrosis. There is general agreement that a large part of the cell death caused by myocardial reperfusion injury occurs during the first few minutes of reperfusion, and that early treatment is required to prevent it. Myocardial hypothermia may attenuate the pathological mechanisms mentioned above. However, limited data are available on the beneficial effects of hypothermia to protect the myocardium from reperfusion damage. In animals, several studies demonstrated a protective effect of hypothermia on the infarction area. This effect was only noted when hypothermia was established before reperfusion. Hypothermia is therefore thought to attenuate several damaging acute reperfusion processes such as oxidative stress, release of cytokines and development of interstitial or cellular edema. Furthermore, it has been shown that induced hypothermia resulted in increased ATP-preservation in the ischemic myocardium compared to normothermia. The intracoronary use of hypothermia by infused cold saline in pigs was demonstrated to be safe by Otake et al. In their study, saline of 4°C was used without complications (such as vasospasm, hemodynamic instability or bradycardia) and it even attenuated ventricular arrhythmia significantly. Studies in humans, however, have not been able to confirm this effect, which is believed to be mainly due to the fact that the therapeutic temperature could not reached before reperfusion in the majority of patients or not achieved at all. Furthermore, in these studies it was intended to induce total body hypothermia, which in turn may lead to systemic reactions such as shivering and enhanced adrenergic state often requiring sedatives, which may necessitate artificial ventilation. In fact, up to now any attempt to achieve therapeutic myocardial hypothermia in humans with myocardial infarction, is fundamentally limited because of four reasons: 1. Inability to cool the myocardium timely, i.e. before reperfusion 2. Inability to cool the diseased myocardium selectively 3. Inability to achieve an adequate decrease of temperature quick enough 4. Inability to achieve an adequate decrease of temperature large enough Consequently, every attempt to achieve effective hypothermia in ST-segment myocardial infarction in humans has been severely hampered and was inadequate. In the last two years, the investigators have developed a methodology overcoming all of the limitations mentioned above. At first, the investigators have tested that methodology in isolated beating pig hearts with coronary artery occlusion and next, the investigators have tested the safety and feasibility of this methodology in humans. Therefore, the time has come to perform a proof-of-principle study in humans, which is the subject of this protocol.
The aim was the comparison of the perioperative time courses of matrix metalloproteinase-9 (MMP-9) and its inhibitor (TIMP-1) during elective carotid artery stenting (CAS). The investigators used a matched, historical carotid endarteriectomy group as controls. Blood samples at four time points: T1: preoperative; T2: 60 minutes after stent insertion; T3: first postoperative morning; and T4: third postoperative morning. Plasma was isolated from heparin anticoagulated blood samples by low speed centrifugation at 4 °C, and stored at -80 °C until analyzed in a single batch at the end of the study. Plasma concentrations of MMP-9 and TIMP-1 were expressed as ng/ml.
The MMP-9-TIMP-1 system has been implicated in many physiological and pathophysiological conditions including vascular surgery related ischemic-reperfusion injury. Our key aims were to establish the early perioperative time courses of the aforementioned system in aorto-bifemoral bypass and aorta stentgraft implantation procedures and to find correlation between the MMP-9-TIMP-1 system and the cross-clamp time. Patients were prospectively enrolled after Ethical Committee approval. Blood samples were taken at four different time points (T1-4): T1: right before surgery, T2: 60 min after the cross-clamp release, T3: first postoperative morning, T4: third postoperative morning. Plasma was isolated from heparin anticoagulated blood samples by low speed centrifugation at 4 °C, and stored at -80 °C until analyzed in a single batch at the end of the study. MMP- 9 and TIMP-1 were determined by the quantitative sandwich enzyme-linked immunosorbent assay (ELISA) techniques according to the manufacturer instructions (R&D Systems Inc., Minneapolis, Minnesota, USA). In comparison with standard curves, the concentrations of MMP-9 and TIMP-1 in plasma were determined spectrophotometrically (Multiskan Ascent microplate photometer, Type: 354, Thermo Electron Corporation, Waltham, Massachusetts, USA) by reading the absorbance at 450 nm. Plasma concentrations of MMP-9 and TIMP-1 were expressed as ng/ml.
One consequence of tissue damage caused by tourniquet is ischemia-reperfusion injury. Short-term ischemia leads to vasodilatation and reactive hyperemia resulting in post-ischemic reperfusion microcirculation failure and tissue edema that extends from 30 minutes to 4 hours. SCUBE-1 is a newly defined cell surface molecule. It emerges from many developing cells, including endothelium and platelets. Immunohistochemical demonstration of subendothelial matrix deposition in atherosclerosis in humans. We did not find any study that showed the post-ischemic regression of scube 1, which was shown to be significantly higher in ischemic events in the literature. in this study is aimed to investigate the location / sensitivity of SCUBE-1 in diabetics and nondiabetics after application of regional anesthesia for ischemia-reperfusion injury induced by tourniquet application in knee prosthesis attempts in our aimed patients and compare this with other total antioxidant status (TAS) and MDA of ischemia-reperfusion parameters
Liver transplantation is the gold standard treatment for patients with end-stage liver disease. Despite its outstanding success, liver transplantation still entails certain complications including ischemia-reperfusion injury. Remote ischemic preconditioning is a novel and simple therapeutic method to lessen the harmful effects of ischemia-reperfusion injury, however, the majority of remote ischemic preconditioning studies on hepatic ischemia-reperfusion injury have been animal studies. Therefore, our aim was to assess the effects of remote ischemic preconditioning on postoperative liver function in living donor hepatectomy.