34 Clinical Trials for Various Conditions
Lysine analogs, like tranexamic acid (TXA) or epsilon aminocaproic acid (EACA), are antifibrinolytic agents routinely administered in children undergoing different surgeries associated with a high bleeding risk (e.g. cardiac, craniofacial, and orthopedic surgeries). Although there is a growing literature regarding the pharmacokinetic characteristics of these drugs in children, the plasmatic concentration required to completely inhibit fibrinolysis remains to be determined. In this in vitro study, the investigators will use an experimental model of fibrinolysis designed for rotational thromboelastometry (ROTEM®) to determine the minimal concentration inhibiting fibrinolysis for both TXA and EACA. In addition, this study will be used to create and validate a new experimental assay to measure fibrinolysis and the effect of antifibrinolytic agents.
It is common practice to use antifibrinolytic agents before and during cardiopulmonary bypass. They are not without side effects. The investigators want to show that there is no proof of fibrinolysis in standard sternotomy cardiac surgery patients before cardiopulmonary bypass, and that antifibrinolytic agents should only be started on cardiopulmonary bypass.
The aim of this study is to determine how two different types of iodinated contrast media (CM) agents, low-osmolar ionic ioxaglate and iso-osmolar non-ionic iodixanol, affect specific markers of thrombogenesis and platelet function in patients undergoing coronary angiography, and if the use of bivalirudin, a direct thrombin inhibitor used during percutaneous coronary intervention (PCI), affects any contrast-related changes in thrombogenesis and platelet function.
The purpose of the study is to see how two classes of blood pressure medications,angiotensin-converting enzyme inhibitors (Ace inhibitors) and angiotensin receptor blockers (ARBs), differ in their long term effects on certain chemicals in the body and on the carotid arteries.
The purpose of the study is to determine if giving isosorbide,a drug that is used to treat chest pain, affects blood vessel release of an anti-clotting factor.
Each year over a million patients worldwide undergo cardiac surgery requiring cardiopulmonary bypass (CPB).1 CPB is associated with significant morbidity including hemodynamic instability, the transfusion of allogenic blood products, and inflammation. Blood product transfusion increases mortality after cardiac surgery. Enhanced fibrinolysis contributes to increased blood product transfusion requirements in the perioperative period. CPB activates the kallikrein-kinin system (KKS), leading to increased bradykinin concentrations. Bradykinin, acting through its B2 receptor, stimulates the release of nitric oxide, inflammatory cytokines and tissue-type plasminogen activator (t-PA). Based on data indicating that angiotensin-converting enzyme (ACE) inhibitors reduce mortality in patients with coronary artery disease, many patients undergoing CPB are taking ACE inhibitors. While interruption of the renin-angiotensin system (RAS) reduces inflammation in response to CPB, ACE inhibitors also potentiate the effects of bradykinin and may augment B2-mediated change in fibrinolytic balance and inflammation. In contrast, angiotensin II type 1 receptor antagonism does not potentiate bradykinin and does not inhibit bradykinin metabolism. Studies in animals suggest that bradykinin receptor antagonism inhibits reperfusion-induced increases in vascular permeability and neutrophil recruitment.A randomized, placebo controlled clinical trial of a bradykinin B2 receptor antagonist demonstrated some effect on survival in patients with systemic inflammatory response syndrome and gram-negative sepsis. In addition, we and others have shown bradykinin B2 receptor antagonism reduces vascular t-PA release during ACE inhibition. The current proposal derives from data from our laboratory and others elucidating the role of the KKS in the inflammatory, hypotensive and fibrinolytic response to CPB. Specifically, we have found that CPB activates the KKS and that ACE inhibition and smoking further increases bradykinin concentrations. During CPB, bradykinin concentrations correlate inversely with mean arterial pressure and directly with t-PA. Moreover, we have found that bradykinin receptor antagonism attenuates protamine-related hypotension following CPB. The current proposal tests the central hypothesis that the fibrinolytic and inflammatory response to cardiopulmonary bypass differ during angiotensin-converting enzyme inhibition and angiotensin II type 1 receptor antagonism.
The null hypothesis is that patients receiving either thoracoscopy or fibrinolysis for empyema recover in the same amount of time. Therefore, we will test this by randomizing the next 40 patients who consent to the study to one treatment or the other.
The specific aim for our study is to measure coagulation system activation and fibrinolysis following transdermal versus sublingual versus oral estradiol versus in transgender women. Hypothesis: Transdermal estradiol will result in less coagulation system activation and no effect on plasminogen activator inhibitor (PAI-1) or tissue-type plasminogen activator (t-PA). Oral estradiol will result in the most coagulation system activation and effect on PAI-1 and t-PA: Oral estradiol \> sublingual estradiol \> transdermal estradiol. A prospective crossover study will include ten subjects given estradiol 1 mg daily and instructed to take it orally, sublingually, or transdermal for 2 months with a 2-week washout period between routes of administration. Labs will be measured 7 times during the study.
This study investigates a possible fibrinolytic effect of sequential compression devices (SCDs). These devices have been used for decades to reduce risk of deep venous thrombosis (DVT). However, a randomized study in plastic surgery outpatients has not been done. This study is undertaken to remedy that deficiency in our knowledge base.
The purpose of this prospective randomized clinical trial is to compare two currently accepted standard-of-care treatment strategies: Medical thoracoscopy as compared to instillation of intrapleural tissue Plasminogen Activator (TPA) and human recombinant Deoxyribonuclease (DNase) for the management of empyema or complicated parapneumonic effusion (CPPE) in adults.
The purpose of this prospective randomized clinical trial is to compare two currently accepted standard-of-care treatment strategies: Medical thoracoscopy as compared to instillation of intrapleural tissue Plasminogen Activator (TPA) and human recombinant Deoxyribonuclease (DNase) for the management of empyema or complex parapneumonic effusion (CPPE) in adults.
This study hopes to determine the optimal antifibrinolytic dosing to decrease bleeding and blood transfusion after cardiac surgery without increasing adverse events
Project Summary We propose an ancillary study to The Heart and Lung Failure Pediatric Insulin Titration trial (HALF PINT), which is investigating the impact of normalizing blood glucose using insulin infusions on clinical outcomes among children with hyperglycemia and heart and lung failure. In this ancillary study, we will measure plasma levels of inflammatory, coagulation, and fibrinolysis proteins and genotype DNA for polymorphisms among patients enrolled in the HALF PINT trial. The results from this ancillary study will help us to understand potential mechanisms through which normalizing blood glucose provides benefit, which may lead to development of new therapeutic strategies in critically ill children
One postoperative complication following unilateral or bilateral total knee arthroplasty is thrombosis (blood clot formation). In this prospective, double-blinded randomized controlled clinical trial, researchers are investigating the effect of steroids on biochemical markers of thrombosis. Furthermore, elevated cellular markers of thrombosis (specifically IL-6) have been linked to postoperative depression following total knee arthroplasty surgery. Hence the investigators are also checking if use of hydrocortisone, a steroid, may help reduce the incidence of postoperative depression. Other studies have shown that surgery causes some reaction in the body that is consistent with inflammation. When the inflammation is extensive, it may affect different parts of the body. It may also lead to clotting disorders and result in blood clots. In a previous study by this principal investigator (see reference 22, "Use of low-dose steroids in decreasing cytokine release during bilateral total knee arthroplasty"), hydrocortisone was administered over 24 hours following surgery to patients who underwent bilateral total knee arthroplasty. The investigator found lower levels of cellular markers consistent with inflammation (specifically the protein, IL-6). Steroid use also showed additional benefits, such as decreased pain and better range of motion at the knee. In this study, investigators recruit patients undergoing total knee arthroplasty surgery. Patients are randomized to receive three 100 mg doses of hydrocortisone or three doses of a saline placebo. In addition to analyzing patients' blood samples for hydrocortisone's effect on clotting factors (i.e. IL-6), investigators record patients' pain scores and patients' oral analgesic use. To assess patients' well-being, patients are contacted one month and 3 months following their surgeries and administered the Patient Health Questionnaire (see reference 23, "The PHQ-9: validity of a brief depression severity measure.") arthroplasty.
The objective of this study is to evaluate the utility of fibrinolysis when draining an abdominal abscess as defined by length of stay after drainage.
The investigators hypothesize that nebivolol will improve endothelial t-PA release in adult humans with elevated blood pressure to a greater extent than either metoprolol or placebo. The investigators further hypothesize that the improvement in the capacity of the vascular endothelium to release t-PA with nebivolol is mediated, in part, by the compound's antioxidant properties.
The purpose of this study is to determine the effect of chronic PDE5 inhibitor therapy on glucose metabolism in persons with prediabetes.
Total hip arthroplasty (THA) is associated with blood loss ranging from 300 to 2000 mL. Tranexamic acid (TXA) is frequently administered prophylactically during this procedure to reduce blood loss by inhibiting fibrinolysis or by stopping naturally occurring clot resolution. TXA is employed currently based on a surgeon's preference. The objective of this study is to quantitate the degree of fibrinolysis using rotational thromboelastometry (ROTEM) and investigate the role of TXA prophylaxis on blood loss in patients undergoing THA in a double-blind fashion. Our hypothesis is that fibrinolysis is minimal at most and TXA prophylaxis is not necessary during THA. All patients, whether they receive TXA or normal saline, will not be at risk, as at this time no data exists to determine which approach is safer or more effective. This is the first study to compare TXA vs. placebo in a double-blinded, randomized controlled trial.
The investigators prepared a novel study of tranexamic acid (TXA) designed to estimate the quantity of blood loss in women undergoing elective repeat cesarean deliveries. This is the first trial to utilize a prophylactic dose of TXA prior to incision followed by a subsequent prophylactic dose at placental delivery in obstetric patients undergoing scheduled cesareans. The purpose of this study is to quantify blood loss during uncomplicated repeat cesarean deliveries with and without TXA. The central hypothesis is that TXA administration reduces blood loss and fibrinolysis in women undergoing repeat cesarean sections.
Each year over a million patients worldwide undergo cardiac surgery requiring cardiopulmonary bypass (CPB). CPB is associated with significant morbidity including the transfusion of allogenic blood products, inflammation and hemodynamic instability. In fact, approximately 20% of all blood products transfused are associated with coronary artery bypass grafting procedures. Transfusion of allogenic blood products is associated with well-documented morbidity and increased mortality after cardiac surgery. Enhanced fibrinolysis contributes to increased blood product transfusion in the perioperative period. The current proposal tests the central hypothesis that endogenous bradykinin contributes to the hemodynamic, fibrinolytic and inflammatory response to CPB and that bradykinin receptor antagonism will reduce hypotension, inflammation and transfusion requirements. In SPECIFIC AIM 1 we will test the hypothesis that the fibrinolytic and inflammatory response to CPB differ during ACE inhibition and angiotensin II type 1 receptor antagonism. In SPECIFIC AIM 2 we will test the hypothesis that bradykinin B2 receptor antagonism attenuates the hemodynamic, fibrinolytic, and inflammatory response to CPB. In SPECIFIC AIM 3 we will test the hypothesis that bradykinin B2 receptor antagonism reduces the risk of allogenic blood product transfusion in patients undergoing CPB. These studies promise to provide important information regarding the effects of drugs that interrupt the RAS and generate new strategies to reduce morbidity in patients undergoing CPB.
The study investigators are interested in learning more about how drugs, that are given to children by their health care provider, act in the bodies of children and young adults in hopes to find the most safe and effective dose for children. The primary objective of this study is to evaluate the PK of understudied drugs currently being administered to children per SOC as prescribed by their treating provider.
Fibrinolysis is the body's process that prevents blood clots. The investigators hypothesize that patients presenting with acute pulmonary embolism (PE) or blood clots in the lungs differ in their fibrinolytic deficit phenotype. The investigators aim to use biomarkers directly involved in endogenous fibrinolytic cascade including PAI-1, Alpha-2-Antiplasmin (A2A), TAFI, D-dimer, and Fibrinogen to phenotypically characterize patients presenting with acute PE and to correlate these biomarkers with clinical, echocardiographic, computed tomography (CT), and functional status outcomes.
'The TOP Study' is a prospective cohort study whose main objective is to develop better prognostic biomarkers and identify children at risk of adverse thrombotic outcomes very early in the course after an initial venous thromboembolic events (VTE). The study will compare biomarkers in children that develop poor VTE outcomes (such as recurrence, postthrombotic syndrome and post PE impairment ) after an initial VTE with those that do not develop such outcomes.
This is a phase II, pragmatic, prospective, randomized, double-blind, adaptive clinical trial examining the efficacy of statins and aspirin in the reduction of acute lung injury and venous thromboembolism in patients with fibrinolysis shutdown.
1. Further characterize the incidence of hyperfibrinolysis in cirrhotics 2. Correlate hyperfibrinolysis with 1. hepatitis C 2. alcoholic liver disease 3. the subset of a\&b with renal failure with and without dialysis 3. Better describe the hyperfibrinolytic ROTEM profile in cirrhotics
The potential for nattokinase to "thin" blood and to reduce blood clotting by positive antithrombotic and fibrinolytic effects presents a unique opportunity to safely study such effects on cardiovascular disease and cognition. Unfortunately, such studies of antithrombotic and fibrinolytic pathways of prevention have been limited due to lack of safe compounds and the adverse reactions associated with current agents such as Coumadin. Nattokinase, an over-the-counter supplement used for cardiovascular health, is the most active functional constituent of natto, a fermented soy product. Natto has been consumed primarily by the Japanese for over 1000 years, a population with one of the lowest risks for cardiovascular disease and dementia. Cardiovascular disease and dementia remain the most challenging age-related health risks of the 21st century for Americans necessitating development of further effective preemptive strategies. Whether reducing the propensity for thrombus formation and/or increasing fibrinolytic activity can prevent the progression of atherosclerosis and cognitive decline has not yet been determined. Using nattokinase under primary prevention conditions, the investigators propose to conduct a randomized, double-blinded, placebo-controlled trial to determine whether decreasing atherothrombotic risk can reduce the progression of subclinical atherosclerosis and cognitive decline. The investigators propose to randomize 240 healthy non-demented women and men to nattokinase supplementation or to placebo for three years. The primary trial endpoints will be measurement of carotid arterial wall thickness and arterial stiffness, early changes of atherosclerosis that can be measured safely by non-invasive imaging techniques. The secondary trial endpoint will be ascertained through change in cognition measured by a neuropsychological battery. In addition, biochemical blood measurements and in vitro studies will be conducted to compare the effects of nattokinase relative to placebo on blood coagulation and thrombus break-down capabilities, blood flow properties, inflammation and inflammatory activation of endothelial cells that line blood vessels.
This study involves doing platelet function testing in patients who have undergone fibrinolysis. Fibrinolysis (Use of clot busting medicine in heart attack) is the standard of care to restore blood flow in blocked arteries as soon as possible after the "Heart attack" in rural health center where access to cardiac catheterization is one hour away. Fibrinolysis is done by the emergency room physician in a timely fashion to minimize the damage of the myocardium. Additionally anti-platelet regimen as adjuvant for patient undergoing fibrinolysis has been well studied in many trials. In this study investigators will use clopidogrel or ticagrelor in randomized fashion to evaluate anti- platelet effect by measuring efficacy in vivo (pharmacodynamics) and blood levels of both drugs (Pharmacokinetics).
The purpose of this study is to determine if the EKOS EkoSonic® Endovascular Device when used in conjunction with recombinant tissue plasminogen activator (t-PA) as a treatment for acute PE will decrease the ratio of right ventricle (RV) to left ventricle (LV) diameter within 48 =/- 6 hours in participants with massive or submassive PE.
Bradykinin stimulates t-PA release from intact vessels, but not from endothelial cells in culture. It has been proposed that the nerves of blood vessels are the source of bradykinin stimulated t-PA release. In order tho test this hypothesis, we intend to infuse bradykinin into the brachial (arm) artery and the coronary arteries of heart transplant recipients and control subjects. This is because heart transplant recipients do not have nerves to their coronary arteries. This protocol studies the effects of bradykinin on t-PA release in the forearm of transplant recipients. The brachial artery has intact nerves. Separate protocols address coronary artery infusions in healthy subjects and transplant recipients and forearm infusions in healthy subjects.
Heart transplant recipients do not have nerves to their hearts. This protocol tests the hypothesis that bradykinin mediated t-PA release in the coronary arteries will be reduced in heart transplant recipients compared to healthy subjects. This study will compare heart transplant recipients to healthy controls who are undergoing cardiac cath for standard of care purposes (separate protocol) and compare the coronary arteries to the forearm in transplant recipients (separate protocol) and healthy controls (separate protocol).