Active clinical trials for "Reperfusion Injury"

A Randomized, Double-blind, placebo-controlled Trial to Evaluate the Efficacy of Oral Nam for the Prevention of Acute Kidney Injury in Patients Undergoing On-Pump Cardiac Surgery

Acute myocardial infarction (AMI) remains the leading cause of death worldwide. In this scenario, early coronary reperfusion is the main therapeutic strategy as it substantially reduces mortality. Paradoxically, however, reperfusion triggers additional tissue damage that accounts for about 50% of the infarcted heart mass, i.e., ischemia and reperfusion injury (IRL). In this context, sphingosine-1-phosphate (S1P) is a sphingolipid synthesized by sphingosine kinases (Sphk), carried in plasma bound to high-density lipoprotein (HDL) and released after cellular damage such as LIR. Particularly, in animal models of AMI, therapies targeting downstream S1P receptor signaling triggered by HDL/S1P are able to promote endothelial barrier functions and attenuate secondary damage to LIR. Thus, the molecular control of sphingosine kinase 1 (Sphk1) transcription during LIR in vivo or during hypoxia/reoxygenation (H/R) in vitro may represent an important mechanism for maintaining endothelial homeostasis since it promotes the generation of S1P and this may promote subsequent HDL enrichment. Thus, the role of pioglitazone hydrochloride 45mg/day for five days in volunteers undergoing coronary artery bypass grafting (BVR) will be investigated in order to verify the vascular expression of SPhk1, transcriptome and vascular proteome remodeling, as well as S1P content in HDL.

The goal of this clinical trial is to investigate the role of colchicine in reducing the rate of myocardial reperfusion injury in patients with ST-elevation myocardial infarction after primary percutaneous coronary intervention. The main questions it aims to answer are: Does colchicine reduce the rate of myocardial reperfusion injury ? Does colchicine reduce the concentration of markers of myocardial reperfusion injury (NLRP3, ASC, caspase, and troponin) ? Participants will Be grouped into intervention group and control group blindly. Patients in the intervention group receive loading dose of colchicine 1 x 2 mg followed by colchicine 2 x 0,5 mg daily for two consecutive days. Patients in the control group receive loading dose of placebo (lactose) 1 x 2 mg followed by lactose 2 x 0,5 mg daily for two consecutive days. Undergo peripheral blood vein examination before primary percutaneous coronary intervention, after primary percutaneous coronary intervention, 24 hour after primary percutaneous coronary intervention, and 48 hour after primary percutaneous coronary intervention. Researchers will compare intervention group and control group to see if colchicine reduces the rate of myocardial reperfusion injury and reduces the concentration of markers of myocardial reperfusion injury (NLRP3, ASC, caspase, and troponin) in patients with ST-elevation myocardial infarction after primary percutaneous coronary intervention.

The aim of the study is to investigate the effect of dapagliflozin or placebo on acetylcholine (Ach)- or nitroglycerin (GTN)-induced vasodilation of the forearm resistance vasculature, as determined by FBF measurement before and 10 minutes after 20 minutes of forearm ischemia.

The overall primary objective of the PULSE-MI trial is to test the hypothesis that administration of single-dose glucocorticoid pulse therapy in the pre-hospital setting reduces final infarct size in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI)

There remains a clinical need to improve health outcomes in patients with ischemic heart disease (IHD) the leading cause of death and disability in Singapore and worldwide. One neglected therapeutic target is 'myocardial reperfusion injury' in ST-segment elevation myocardial infarction (STEMI) patients treated by primary percutaneous coronary intervention (PPCI). This results in microvascular obstruction (MVO) and cardiomyocyte death and contributes upto 50% of the final myocardial infarct (MI) size. Cangrelor, a potent intravenous platelet P2Y12 inhibitor with rapid onset and offset of action, has been demonstrated in experimental animal studies to reduce MI size when administered prior to reperfusion. Whether Cangrelor given together with Ticagrelor would be more effective at reducing MI size in STEMI patients treated by PPCI is not known and is investigated in the Platelet Inhibition to Target Reperfusion Injury (PITRI) trial.

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: Inability to cool the myocardium timely, i.e. before reperfusion Inability to cool the diseased myocardium selectively Inability to achieve an adequate decrease of temperature quick enough 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 overall purpose of this study is to evaluate the safety, pharmacokinetics and preliminary efficacy of a five-days post-operative course of Treprostinil in liver transplant patients. The hypothesis of this study is that Treprostinil can be safely administered post-operatively in liver transplant patients. Once safety is documented future studies will address its ability to ameliorate or prevent reperfusion mediated dysfunction of the liver graft and thereby reduce morbidity, leading to shorter hospital stays as compared to historical controls.

Ischemia perfusion injury (IRI) is a major cause of organ injury during kidney transplantation. Currently there are no treatments for IRI other than dialysis. Preliminary studies in female mice have found protection from IRI when given short term estrogen supplements. This study will look at the effect of intravenous estrogen given peri-operatively to reduce the effect of IRI in female kidney transplant recipients.

Renal artery stenosis is one the leading cause of secondary hypertension. Previous randomized controlled trials in humans have failed to demonstrate an improvement of renal function after stenosis dilation, probably because of a selection bias with more severe patients being excluded from randomization. Renal ischemia-reperfusion injuries have also not been taken into account. Indeed, reperfusion leads to a rapid renal blood flow recovery associated with renal ischemia-reperfusion injuries. Mitochondrial permeability transition pore (mPTP) is a key player in the occurrence of ischemia reperfusion injuries because its opening leads to mitochondria leakage and cell death. However, preconditioning whether pharmacological or ischemic can prevent mPTP opening and protect cells. Ciclosporin A can prolong mPTP closing during reperfusion and reduce renal and cardiac tissular lesions. Another mPTP blocker (Bendavia) has been associated with an improvement of renal blood flow (RBF) and glomerular filtration rate (GFR) after renal artery stenosis dilation at 6 weeks in pigs. Based on a recent study, dilation overall benefit could be secondary to an improvement of the contralateral kidney GFR and tissue oxygen content, requiring a single kidney evaluation of those renal functional parameters. The investigators previously demonstrated that dose and timing of ciclosporin A preconditioning is key to protect kidneys from ischemia-reperfusion injuries. Previous controlled trials that failed to demonstrate a benefit of ciclosporin A conditioning have used post conditioning on necrotic cells. Considering kidney ischemia-reperfusion injuries, preconditioning have led to more encouraging results compared to ciclosporin A post conditioning in animals. Therefore the investigators aim to conduct the first clinical study of ciclosporin A preconditioning for prevention of kidney ischemia-reperfusion injuries after renal artery stenosis dilation. Using renal functional imaging and the new PET-MRI (Positron Emission Tomography-Magnetic Resonance Imaging) combined device, the investigators will evaluate kidney perfusion, oxidative metabolism, glomerular filtration rate and oxygen content before and 3 months after renal artery stenosis dilation with or without a ciclosporin A preconditioning.