View clinical trials related to Aspirin Resistance.
Filter by:The purpose of this study is to determine the incidence of aspirin resistance in the population of vascular surgery patients; and to evaluate the changes in the efficacy of aspirin in the first five postoperative days.
Reactive platelet hyperactivity following coronary artery bypass grafting (CABG) might lead to thrombotic complications and major ischemic cardiac events. The aim of this study is to evaluate the changes in platelet reactivity following CABG and to clarify a potentially beneficial effect of dual antiplatelet therapy in the group of patients with documented aspirin resistance following CABG. Platelet function will be assessed by multiple electrode aggregometry. Aortocoronary vein graft disease is comprised of three distinct but interrelated pathological processes: thrombosis, intimal hyperplasia and atherosclerosis. Early vein thrombosis is a major cause of vein graft attrition during the first month after CABG. Bypass patency can be improved with antiplatelet therapy which is the mainstay of treatment for patients after CABG. A beneficial effect of acetylsalicylic acid (ASA) on vein graft patency has been previously shown. Some patients experience thrombotic events despite continuous aspirin administration after CABG. The investigators hypothesized that low responsiveness to aspirin might be a precipitating factor for adverse thrombotic events following CABG. Low responsiveness to ASA, as assessed by platelet function tests, varies widely among patients. The etiology of postoperative platelet hyperactivity remains to be elucidated. In this study a new point-of-care assay named multiple electrode aggregometry (MEA) using a device called Multiplate analyzer (Dynabyte, Munich, Germany) has been utilized. It allows for rapid and standardized assessment of platelet function parameters. This is a prospective randomized trial. The aim of the study is to document whether introduction of dual antiplatelet therapy in patients with ASA resistance will lead to a lower incidence of major adverse cardiac events (MACE) at a six month follow up. The composite endpoint will include death, non-fatal myocardial infarction, stroke and cardiac rehospitalization. All patients will receive 300 mg of ASA starting 6 hours after surgery, provided that the chest tube output is minimal. On postoperative day 4 their platelet function will be assessed using the above mentioned MEA. The patients found to be aspirin resistant will then undergo the process of randomization. The first arm will include patients with ASA resistance in whom no additional antiaggregation will be administered. In the second arm the investigators will include patients who were randomized to receive 75 mg of clopidogrel in addition to the standard antiplatelet regimen of 300 mg of ASA. Platelet function monitoring allows for individual tailoring of the antiplatelet therapy. The goal of this study is to define whether this strategy will lead to improved patient outcomes. Both major and minor bleeding complications will be strictly monitored and reported.
Acetylsalicylic acid (Aspirin, ASA) is the most widely prescribed drug used in primary and secondary prevention of cardiovascular disease. However, aspirin resistance has been described, mostly in cardiac patients and is an independent predictive factor for a poor survival. Two frequent conditions in patients with cardiovascular diseases, diabetes and hypercholesterolemia, are also considered as risk factors for aspirin resistance. Among patients with peripheral arterial disease, those with critical limb ischemia have the worst cardiovascular prognosis. At one year, 23% are dead, 25% have a major cardiovascular event and 25% have a major amputation (which can be combined). Aspirin resistance is poorly studied in these patients, and to our knowledge no study has been made to assess the prognosis value of aspirin resistance on cardiovascular outcomes in critical limb ischaemia patients. Hospitalized critical limb ischaemia patients will be tested for aspirin resistance using the bed-side point of care VerifyNow®, and will be followed during one year, including death, fatal and non-fatal acute coronary syndromes, cardiac decompensation, stroke, and major amputation.
The purpose of this research is to study why some people do not respond to the benefits of aspirin therapy. The benefit of aspirin is cardioprotection, or decreasing the risk of heart attack and/or stroke. Aspirin works by disabling the platelets, part of the blood cells used in clotting, from sticking together and forming blood clots, thus protecting the heart. It has been observed that failure to respond to aspirin therapy occurs in about 10% of the general population and that despite taking aspirin everyday, this group of non- responders is not getting protection for their heart. The investigators would like to determine why and how this happens.
Dialysis patient could be more aspirin resistant than the general population based on data from chronic kidney disease patients
Aspirin resistance is the persistent platelet activation, demonstrated by platelet function tests (1). The hypothesis is that:LDL lowering by statin in patients with aspirin resistance can improve the effect of aspirin due to the potential decreasing of cholesterol content in the platelet membranes. Patients and methods:Forty hypercholesterolemic patients with aspirin resistance after 5 days of treatment with aspirin and high LDL and triglycerides<300 mg/dL, will be enrolled. Ten healthy volunteers will be the control group.