View clinical trials related to Platelet Dysfunction.
Filter by:This study evaluates the impact of platelet transfusion on geriatric patients with platelet dysfunction from Traumatic Brain Injury. The authors hypothesize that patients will recover better if their platelet dysfunction is corrected with platelet transfusion.
The purpose of this investigation is to evaluate when genetic variation in the carboxylesterase 1 (CES1) gene influences antiplatelet therapy response, as assessed by ex vivo platelet aggregometry, in healthy participants treated with clopidogrel and ticagrelor. We hypothesize that genetic variation in CES1 will significantly impact on-clopidogrel platelet aggregation while having a minimal effect in ticagrelor-treated subjects. Specific Aim: To conduct a prospective randomized crossover study of clopidogrel and ticagrelor in healthy individuals stratified by CES1 genotype. Participants will be recruited by CES1 genotype into a randomized crossover study of clopidogrel (75 mg daily for 7d) and ticagrelor (90 mg twice daily for 7d) with extensive phenotyping including ex vivo platelet aggregometry performed pre- and post-drug administration in order to assess the interaction of genotype and drug choice on on-treatment platelet function.
This study aims to assess independent factors associated with the clinical decision to discontinue ASA preoperatively in patients undergoing elective non-cardiac surgery.
Acute upper gastrointestinal bleeding (AUGIB) is a common medical emergency. In an ageing population, antiplatelet drugs are increasingly being prescribed for treatment and prophylaxis against cardiovascular thrombo-embolic events. In many patients, platelet dysfunction mostly acquired is the principal cause of bleeding. To clinicians, the management of patients on antiplatelet drugs or anticoagulants is a challenge. One has to carefully balance the bleeding against thrombo-embolic risks. Therefore measuring platelet function should be integral in the management plan. A quantitative measurement allows titration of platelet function in accordance with bleeding or thromboembolic risk. Platelet function has not been studied in a large cohort of patients with acute upper gastrointestinal bleeding. As a first step, the study will determine if platelet dysfunction is associated with clinical outcome. In this prospective, observational single centre cohort study of consecutive patients with overt signs of acute upper gastrointestinal bleeding, their platelet function by point of care tests (light transmittance aggregometry, verify now p2y12,the platelet function analysis system (PFA-100) upon their admissions. Patients will be followed up for 30 days after trial enrollment. The primary endpoint is defined as significant bleeding that requires interventions (endoscopic, radiologic or surgery). Secondary end points include cardio- and cerebrovascular thrombo-embolic events and all cause deaths. A receiver operating characteristic (ROC) curve analysis is calculated for each point-of-care test to evaluate if individual test can distinguish between patients with and without primary end point. This study aims to evaluate the capability of platelet function tests to predict clinical outcome in patients with AUGIB. Logistic regression models will then be built in search for independent correlates to the primary and secondary endpoints and to adjust for confounding variables.
Patients who are genetically diagnosed with the recently reported and rare Wolfram syndrome type 2 ( WFS2) and have the degenerative and symptomatic disease including signs such as diabetes, platelet aggregation defect or visual problems will be asked to participate in this study. Knowing the pathomechanism of WFS2 with rapid cell death, after doing baseline investigations to asses the severity of their disease, the participants will be offered a chelator therapy with in addition to the antioxidant Acetylcystein, in diabetic patients an Incertin (GLP-1 ) therapy will be offered as well. The baseline investigations will be repeated after 2 months and after 5 months of therapy in order to asses the progression of the disease and to show if the chelator and anti oxidant therapy and in diabetic patients the GLP-1 therapy could stop the progression of the disease.
In this non-interventional multicentre, prospective, observational cohort study, the efficacy of desmopressin is evaluated in patients with platelet dysfunction due to acetylsalicylic acid or cox-1-inhibitors within the context of surgical procedures.
The primary purpose of the study is to evaluate a standardized method of screening for platelet signalling defects in patients with constitutional disorders of platelet function of unknown origin. We hypothesize that such defects are under-diagnosed in patients, due to heavy workup and requirement of relatively large blood sample by conventional biochemical methods. We propose to analyse kinase signalling downstream platelet membrane receptors using multiplex flow cytometry quantification and fluorescent platelet barcoding.
The purpose of this study is to evaluate the effect of a loading dose of two different statins on platelet reactivity (atorvastatin, metabolized by CYP3A4, and rosuvastatin, which is rather independent of this enzyme)in patients at least 5 days in therapy with aspirin and clopidogrel (with or without an undergoing treatment with statins) undergoing PCI for coronary disease with chronic stable angina and/or evidence of inducible myocardial ischemia.
Impedance aggregometry (IA) (Multiplate®)is a new whole blood platelet function test with potential use in anesthesia and intensive care. Most anesthetic drugs have been shown to have in vitro antiplatelet activity. The goal of this in vitro study is to evaluate the effect of several drugs, frequently used in cardiac anesthesia and intensive care, on platelet function as measured by IA
Study hypothesis: Desmopressin (DDAVP) can improve platelet function under influence of aspirin, hemodilution and mild hypothermia Mild hypothermia (34-35oC) is known to cause platelet dysfunction. This could lead to increased surgical bleeding and increased transfusion requirement during surgery. Although this hypothermia-induced platelet dysfunction seems to be reversible with warming, this is not always possible or desirable. Desmopressin (DDAVP) is a drug which has proven efficacy in improving platelet function in uraemic and cirrhosis patients, and in reducing blood loss in selected surgeries. In a recent study, we have found that subcutaneous injection of 1.5 mcg (1/10th the usual dose) is already sufficient to fully reverse the platelet dysfunction seen at 32oC. We have demonstrated in another study that prolongation of the bleeding time in a 20% hemodiluted sample predicts increased postoperative bleeding after total knee replacement. We have therefore designed this study as a follow up to our last two studies on DDAVP and hypothermia, to investigate whether hemodilution affects hypothermia induced platelet dysfunction and the response to DDAVP. In addition, another common cause of perioperative platelet dysfunction is the intake of COX inhibitors, particularly aspirin by patients. Therefor the effect of aspirin on hypothermia induced platelet dysfunction and the response to DDAVP, will also be investigated.