View clinical trials related to Thromboembolism.
Filter by:The objective of this proposal is to develop and validate diagnostic and prognostic (including short-term and long-term prognoses) prediction models for patients with venous thromboembolism (VTE) in China.
Venous thromboembolism is a common and serious complication in cancer, and is associated with a substantially increased morbidity and mortality. Furthermore, VTE may be the earliest sign of cancer. Recent studies, however, fail to show a clinical benefit of extended cancer screening in this patient population. Better risk prediction models are therefore warranted to identify VTE patients who would benefit from a rapid and extensive cancer screening. Inflammation and hypercoagulability are considered hallmarks of cancer, and emerging light is being shed on the potential of various markers of inflammation and coagulation in cancer diagnostics and prognostics. Among the inflammatory and thrombotic processes linked to cancer is the neutrophil release of web-like nuclear chromatin (DNA and histones), referred to as neutrophil extracellular traps (NETs). Driven by the tumor environment, NETs have recently been shown to play a central role in tumor progression, metastasis, and tumor-associated thrombosis. The investigators hypothesize that an enhanced inflammatory state may be predictive of an underlying cancer in patients presenting with VTE. The present study is an ongoing prospective study with the primary aim to investigate the diagnostic potential of markers of inflammation, including markers of NETs, in detecting occult cancer in patients presenting with VTE. Secondary aims are to include other biomarkers of cancer, and to assess whether any or a combination of these biomarkers may be prognostic of occult cancer, recurrent thrombotic events, mortality, or cancer disease progression in VTE patients with an underlying malignancy.
Introduction: Venous thromboembolism (VTE), including both deep vein thrombosis and pulmonary embolism, is a frequent cause of morbidity and mortality. The population of critically ill patients is a heterogeneous group of patients with an overall high average risk of developing VTE. No prognostic model has been developed for estimation of this risk specifically in critically ill patients. The aim is to construct and validate a risk assessment model for predicting the risk of in-hospital VTE in critically ill patients. Methods: In the first phase of the study we will create a prognostic model based on a derivation cohort of critically ill patients who were acutely admitted to the intensive care unit. A point-based clinical prediction model will be created using backward stepwise regression analysis from a selection of predefined candidate predictors. Model performance, discrimination and calibration will be evaluated, and the model will be internally validated by bootstrapping. In the second phase of the study, external validation will be performed in an independent cohort, and additionally model performance will be compared with performance of existing VTE risk prediction models derived from, and applied to, general medical patients. Dissemination: This protocol will be published online. The results will be reported according to the Transparent Reporting of multivariate prediction models for Individual Prognosis Or Diagnosis (TRIPOD) statement, and submitted to a peer-reviewed journal for publication.
Hospitalized medical patients have an increased risk of venous thromboembolism (VTE) across the continuum of care, including after hospital discharge. In the APEX Trial of hospitalized patients with acute medical illness, extended-duration post-discharge thromboprophylaxis with oral betrixaban reduced the frequency of asymptomatic proximal deep venous thrombosis (DVT), symptomatic proximal or distal DVT, symptomatic nonfatal pulmonary embolism (PE), or VTE-related death compared with short-duration enoxaparin. Obstacles to integration of these data in the hospitalized Medical Service patient population, including failure to identify at-risk patients, educational gaps in strategies for VTE prevention after discharge, and medication nonadherence, can be overcome with alert-based computerized decision support. This study is a single-center, 400-patient, randomized controlled trial of an EPIC Best Practice Advisory (BPA; alert-based computerized decision support tool) to increase prescription of extended-duration post-discharge thromboprophylaxis and decrease symptomatic VTE in high-risk patients hospitalized with medical illness. Specific Aim #1: To determine the impact of electronic alert-based CDS (EPIC Best Practice Advisory [BPA]) on prescription of extended-duration post-discharge thromboprophylaxis in high-risk patients hospitalized with medical illness who are not being prescribed any prophylactic anticoagulation for VTE prevention after discharge. Specific Aim #2: To estimate the impact of electronic alert-based CDS (EPIC BPA) on the frequency of symptomatic VTE in high-risk patients hospitalized with medical illness who are not being prescribed any prophylactic anticoagulation for VTE prevention after discharge.
A Multi-center, Randomized Controlled Trial to evaluate the safety and efficacy of Fitaya Vena Cava Filter manufactured by Lifetech Scientific (Shenzhen) Co., LTD. for deep vein thrombosis.
The management of venous thromboembolism (VTE) risk in pregnancy still remains a challenge. An individual assessment of the VTE risk is crucial for optimal thromboprophylaxis, but there is no validated tool to help clinicians stratify the risk in pregnant women and introduce prophylactic anticoagulation at the appropriate time. Recommendations mostly based on case-control studies and expert opinions do not accurately reflect the physician's need. In view of the lack of international recommendations with a high level of evidence regarding prophylactic treatment of pregnant women at risk of thrombosis, the use of a risk stratification tool that takes all individual risk factors for VTE into consideration and which aids decisions over prophylaxis regimens may help. Investigators have previously described a VTE risk score (the Lyon-VTE-score), rating patients at increased risk of VTE and recommending individually tailored management. A retrospective evaluation of the initial score showed favorable outcomes in pregnancies with a high risk of thrombosis. A subsequent multicenter prospective study reported promising results using this score and related management strategy. The efficacy and safety after 10 years of prospective use of the Lyon-VTE-score in daily practice to guide the prescription of antithrombotic prophylaxis during pregnancy was recently evaluated and the results showed that the Lyon-VTE-score allows a standardized approach with objective criteria and can help non-specialized centers and young doctors manage these high-risk pregnancies. The results of previous studies provide consistent conclusions on the safety and efficacy of the approach of investigators and give background for a medico-economic study to evaluate costs and consequences of this procedure. The most recent study (2005) evaluating the cost of prophylaxis in pregnant women, evaluated this cost as $1292 for each 6-week cycle of treatment. In addition, the use of such a score offers the prospect of personalized medicine, which is probably more cost-efficient compared to "inclusive, equal treatment for all". In antepartum, the decision to administer thromboprophylaxis should be considered on an individual basis with regard to lowering the absolute risk of thrombosis, the inconvenience of daily subcutaneous heparin therapy and the potential risks of bleeding, heparin-induced thrombocytopenia and osteoporosis. An individual assessment of the VTE risk is crucial for optimal thromboprophylaxis, but there is no validated tool to help clinicians to stratify VTE risk in pregnant women and to introduce prophylactic anticoagulation at the right time. Most of the recommendations are grade 2C. They are mostly based on case-control studies and expert opinions and do not entirely highlight the physicians' need. The originality of this approach is the use of a risk stratification tool that takes all individual risk factors for VTE into consideration and that aids the decision-making process of antenatal anti-thrombotic prophylaxis. This study will personalize care using a score to individually assess the risk and propose appropriate prevention. The main objective of this study is to conduct a medico-economic study to evaluate the efficiency of an innovative strategy integrating the Lyon-VTE-score in the management of pregnant patients with venous thromboembolism risk versus standard care.
This study evaluates the use of a lower INR target (1.5 to 2.5) in patients with a mechanical bileaflet heart valve in the aortic position. This study will inform physicians about whether a lower INR target will decrease the risk of bleeding or increase the risk of blood clot formation and stroke. These results have the potential to reduce the burden of bleeding in patients with a mechanical heart valve who require lifelong warfarin (Coumadin) treatment.
The aim of the study is to assess the prevalence of left atrial thrombus in patients with atrial fibrillation (AF) or atrial flutter (AFI), in whom transesophageal echocardiography is performed before AF/AFl cardioversion or ablation.
This is a pilot study, phase III, multi-centre, double blind, randomized controlled trial of patients with traumatic brain injury (TBI).
Background: Unfractionated heparin (UFH) is a sulfated polysaccharide extracted from porcine intestinal mucosa that enhances the inhibitory activity of the natural anticoagulant antithrombin towards most activated clotting factors (F), particularly FXa and FIIa (thrombin) . Despite the growing interest for low molecular weight derivatives (LMWH), UFH is still widely used for different indications including the treatment of acute thrombosis including venous thromboembolism, coronary syndromes (ACS), and other thrombotic diseases. UFH is administered by parenteral route either intravenous (IV) or sub-cutaneous (SC).Actually, there is evidence that the risk of recurrence of thrombosis is increased when heparin levels fells below the lower limit of the therapeutic range, while the hemorrhagic risk increases with heparin levels above the upper limit of the therapeutic range. Moreover, the anticoagulant response to UFH is highly variable for one individual to another. As the clinical efficacy of heparin is dependent on maintaining an anticoagulant effect above a minimum level, careful laboratory monitoring of UFH treatment is mandatory. For that purpose, two options are offered to the clinicians: i) to evaluate either the prolongation of a global clotting assay, the activated partial thromboplastin time (aPTT) and ii) to measure the heparin-enhanced inhibitory activity of AT toward purified activated factors such as FIIa and FXa using chromogenic substrate-based assays. UFH therapy is still widely monitored by the aPTT, a global clotting assay, that reflects the ability of heparin to enhance the inhibitory activity of AT against FIIa, FXa, and other activated factors. The therapeutic range of aPTT prolongation is highly dependent on the reagent and analyzer used. As the consequence, it must be defined by each laboratory in its own technical conditions (for each reagent batch) to correlate with heparin levels between 0.20 and 0.40 U/mL (protamine sulfate titration), corresponding to anti-FXa activity between 0.30 and 0.70 IU/mL. In that connection, the prolongation of aPTT corresponding to antiFXa activity between 0.30 - 0.70 IU/mL is highly variable depending of the reagents e.g.between 1.6 - 2.7 x control for weakly sensitive reagents and between 3.7 - 6.2 x control for highly sensitive reagents. The use of aPTT has advantages as it is easy-to-perform, quick, inexpensive but faces numerous challenges due to the significant influence of the technical conditions (reagent/instrument) on the test result, to lot-lot variation in reagent sensitivity, to the need of studies to evaluate the therapeutic range, to limited therapeutic range, and also to non-specific prolongation in the case of lupus anticoagulant, factors deficiency, inhibitors or shortening in the case of high factor levels, particularly FVIII.In contrast, the use of chromogenic anti-Xa assays has many advantages particularly a published therapeutic range for UFH i.e. between 0.30 and 0.70 IU/mL, a specificity to its interaction with AT (no Heparin Cofactor II interference by using bovine FIIa or short incubation time) and faces few challenges such as limited availability in some area and a cost that is slightly higher than that of aPTT. In addition, anti-Xa assays allow accurate measurement of all heparin(s) derivatives and particularly LMWHs and fondaparinux. Since the first reports in the mid-eighties, some small sized studies have compared the two monitoring strategies mainly retrospectively designed (7-11). Even though, one single prospective randomized management study evaluated the comparison between the two monitoring strategies with clinical end-points i.e. recurrence of thrombosis and bleeding complication in a cohort of 131 patients with VTE . All concluded to a trend toward higher, or at least similar, safety/efficacy/efficiency when patients were monitored using antiXa activity vs. aPTT. Even though differences were not significant due to the lack of power of these studies.