Active clinical trials for "Thrombosis"

The purpose of this study is to test the hypothesis that using three different techniques to anastomose coronary grafts to the aorta: partial occlusion, single cross clamp, or using the Heartstring anastomotic device, will change the amount of gas and solid microemboli as detected by the EmbodopR transcranial Doppler (TCD) system and consequently the neurocognitive performance of patients after coronary bypass operation.

Deep vein thrombosis is a common condition seen in the Emergency Department. Standard of care for diagnosis of DVT includes a combination of a clinical pre-test probability rule known as Well's criteria, D-dimer blood testing, and Radiology department ultrasound. The purpose of this study is to determine whether Emergency Physicians can safely rule out deep vein thrombosis using Well's criteria and D-dimer blood testing combined with Emergency department bedside ultrasound.

Currently, most emergency physicians have limited access to obtaining formal radiology ultrasound studies, particularly overnight. Many are forced to adopt risky and expensive strategies in managing their patients with suspected deep venous thrombosis (DVT) who present during off-hours: for low risk patients, discharging without anticoagulation and arranging for outpatient studies; for moderate to high risk patients, empirically anticoagulating and admitting to the hospital to await definitive testing. If emergency physicians could reliably perform an accurate ultrasound exam for DVT, such risks could be obviated. This is a prospective, observational cohort study assessing the accuracy of emergency physician diagnosis of proximal DVT using compact ultrasound equipment and a simplified compression technique. The value of color flow doppler and augmentation will also be assessed. Outcomes (sensitivity, specificity, positive likelihood ratio and negative likelihood ratio) will be assessed at 30 days. Prior to enrolling patients in the study, emergency physicians will undertake a 2 hour training course on the performance of the simplified compression technique for the diagnosis of lower extremity DVT. Emergency physicians will perform the DVT ultrasound exam on study subjects with suspected DVT. Clinical management of the study subjects will not be altered; all subjects will proceed to receive a formal DVT ultrasound study by the radiology department which will serve as the criterion reference for the study.

To determine inflammation markers over time in cardiovascular disease. To test the hypothesis that measures of coagulation and fibrinolysis correlate with the incidence of coronary heart disease (CHD) and other thrombosis related disorders, and to help identify those individuals at greatest risk, using the Cardiovascular Health Study (CHS) and Honolulu Heart Program (HHP) populations. These two genetically distinct populations had different event rates for CHD, and offered a unique opportunity to test associations that were uncovered by comparing results across populations.

Reliable data on stent thrombosis (ST) in comatose out of hospital cardiac arrest (OHCA) survivors is lacking. In comatose OHCA survivors suspicion of ST can be made with precise clinical monitoring of the patient with definite confirmation being possible only by coronary angiography or autopsy of deceased patients. However in addition to definite ST which can be confirmed using current protocols, additional ST which are clinically silent are plausible. These could be identified only by systematic coronary angiography of all OHCA survivors or by autopsy of deceased patients. Collectively with definite ST confirmed by coronary angiography upon clinical suspicion the incidence of all forms of ST in survivors of OHCA treated with PCI and hypothermia could be obtained. Consecutive comatose survivors of OHCA treated with percutaneous coronary intervention (PCI) and hypothermia will be included. All study participants will receive treatment per our established clinical protocol and will be followed for 10 days. In all patients in whom clinical suspicion of ST will be made immediate coronary angiography and if necessary PCI will be carried out. In all patients that will die in the observed period of 10 days autopsy will be performed. Survivors however will have an additional control coronary angiography on 10th day after admission, to assess presence of clinically silent ST. We expect that the incidence of true definitive ST in comatose OHCA survivors treated with urgent PCI with stenting and hypothermia is greater than one, which is confirmed on the basis of clinical suspicion by angiography or later with autopsy.

Extracorporeal membrane oxygenation (ECMO) is a lifesaving procedure used to treat severe forms of heart and/or lung failure. It works by the principal of replacing the function of these organs by taking blood from the patient, provide it with oxygen outside the body and return it to the patient in one continuous circuit. Because of the evaluability of better technology, the use of ECMO has exponentially risen over the last decade. This treatment is very invasive and carries a number of risks. It is mostly used in situations where it seems likely that the patient would otherwise die and no other less invasive measure could change this. Still in large registries 50-60% of patients die which is often due to complications associated with the treatment. One of the most important complication is caused by the activation of clotting factors during the contact with the artificial surfaces of the device. This can lead to clot formation inside the patient or the device. To counterbalance this anticoagulation is needed. Because of the consumption of clotting factors and the heparin therapy bleeding complications are also very common in ECMO. Clinicians are challenged to balance these competing risks and are often forced to transfuse blood products to treat these conditions, which comes with additional risks for the patient. Many experienced centres have reported thromboembolic and bleeding events as the most important contributor to a poor outcome of this procedure. However, no international study combining the experience of multiple centres to compare their practice and identify risk factors which can be altered to reduce these risks. This study has been endorsed by the international ECMONet and aims to observe the practice in up to 50 centres and 500 patients worldwide to generate the largest ever published database on this topic. It will concentrate on patients with severe heart failure and will be able to identify specific risk factors for thromboembolic and bleeding events. Some of these factors may be modifiable by change in practice and can subsequently be evaluated in clinical trials. Some of these factors may include target values for heparin therapy and infusion of clotting factors. This study will directly improve patient management by informing clinicians which measures are associated with the best outcome and indirectly helps building trials to increase the evidence further.

Immune thrombocytopenia (ITP) is a rare autoimmune disease (annual incidence: 3-4/105 inhabitants) leading to an increased risk of spontaneous bleeding. ITP is said "primary" when not associated to other systemic disease (lymphoma, systemic autoimmune disease, chronic infectious disease…). First-line treatment is based on corticosteroids. Intravenous immunoglobulin (IVIg) is added in case of serious bleeding. In about 70% of adult cases, ITP becomes persistent or chronic (lasting >3 months and >12 months, respectively). Second-line treatments are then indicated. Among them, thrombopoietin-receptor agonists (TPO-RAs), romiplostim and eltrombopag are increasingly used. Splenectomy is used as ultimate treatment. Paradoxically, the risk of thrombosis is higher in ITP patients in comparison with the general population, due to the release of young hyperactive platelets from bone marrow. The incidence of thrombosis in ITP patients has been estimated between 0.5 and 3/100 patients-years. However, risk factors for thrombosis in ITP are not known, except splenectomy that is used in very few patients now. The role of other ITP treatments in thrombosis occurrence has been evoked, particularly for corticosteroids and IVIg. TPO-RAs have been associated with a risk of thrombosis in clinical trials and pharmacovigilance studies, even in case of low or normal platelet count. However, this risk has not been measured in the real-life practice, adjusted for other risk factors for thrombosis.

Study objective is to determine whether there is an association between genetic variant risk scores and clinical outcomes (percent time in therapeutic range, time to reach therapeutic international normalized ratio (INR), INR ≥ 4, bleeding event, ischemic stroke, death) in participants taking warfarin for atrial fibrillation, deep vein thrombosis (DVT), pulmonary embolism (PE), and/or intracardiac thrombosis.

Patients undergoing electrophysiology studies (EPS) and cardiac ablation procedure for the treatment of cardiac arrhythmias may be at increased risk of deep vein thrombosis (DVT) during or after the procedure, which may lead to pulmonary embolus which can be life threatening. The study will use Doppler ultrasound scanning at 24h and between 10-14 days post EPS and cardiac ablation to assess the incidence of undiagnosed DVT. A positive finding may provide support for a larger clinical trial to assess the benefit of prophylactic anticoagulation post EPS procedure.

This is a prospective, randomized vanguard trial of trauma patients admitted to the trauma surgery service at Intermountain Medical Center who are deemed to be at high risk for venous thromboembolism. Once identified and enrolled, subjects will be randomized to receive bilateral lower extremity duplex ultrasound surveillance versus no surveillance. The study will compare the two groups with regard to deep vein thrombosis, pulmonary embolism, and major and clinically relevant bleeding episode rates, both during the index hospitalization and at 90 days post-discharge.