Active clinical trials for "Venous Thrombosis"

In pregnant women with suspected DVT, a sure diagnosis is mandatory. In non-pregnant patients, sequential diagnostic strategies based on 1) the assessment of clinical probability, 2) D-dimer measurement and 3) compression ultrasonography (CUS) have been well validated. Clinical probability assessment by clinical prediction rules (CPRs) is a crucial step in the management of suspected DVT. However, the most commonly used CPR for DVT, the Wells' score, has never been validated in pregnant women. Recently, the 'LEFt' clinical prediction rule was derived and internally validated. A prospective validation of this rule is now warranted, and we plan to use it in our prospective study. The second step used in the diagnostic strategy including non-pregnant patients is D-dimer measurement. The test has been widely validated in non-pregnant patients and, in association with a non-high clinical probability, it allows to safely rule out DVT. As D-dimer level raise steadily during pregnancy, the specificity of the test decreases and it is less useful in pregnant women. Data from the literature clearly suggest that the usual cut-off set a 500 ng/ml would safely rule out DVT in pregnant women [6]. As the usual cut-off has never been prospectively validated in pregnant women with suspected DVT, we would like to use it in our study. Some studies suggested that complete CUS is safe to rule out DVT in pregnant women. However, this test is not always available. Therefore, a strategy in which the association of clinical probability assessment and D-dimer measurement would allow to safely rule out DVT in a significant proportion of patients without performing a complete CUS, would be of great help in everyday clinical practice and would probably be cost-effective. Therefore, we plan a prospective study to assess the safety of a sequential diagnostic strategy based on the assessment of clinical probability with the LEFt rule, D-dimer measurement and complete CUS in pregnant women with suspected DVT.

Background: During the repair process of deep venous thrombosis, capillary formation is seen from day 18 to day 25. Contrast agent investigation is well known to detect small vessels in arterial disease. We intend to use this method to detect early vascularisation in the thrombus, in order to get more information about the evolution of the thrombosis in vivo. Aims of the study: Investigation of a newly diagnosed occluding venous thrombus with duplexsonography, using contrast agent and compare the degree of vascularization in the same patient after 3 weeks and 3 months. The relative signal intensity difference (baseline to peak) of the time intensity curve (TIC) is measured in defined region of interests (ROI). Comparison of the visibility of revascularisation between color duplexsonography, power mode and contrast agent will be done. Method: Patients with venous thrombosis of the proximal limb veins (femoral or popliteal vein) will be investigated with ultrasound agent in supine position. 5 ml of the contrast agent sulfur hexafluoride is given intravenously into a vein of the dorsal foot. The measurements are done in a defined area, where the thrombus is fully occluding in color Doppler investigation. The regions of interest will be the vessel walls and the centre of the thrombus in cross section view. The signal intensities are measured at baseline and peak (in decibel) in the centre and in the peripheral part of the vein. 20 patients with acute deep venous thrombosis will be included in this pilot study and investigated at baseline, after 3 weeks and 3 months. Previously (before contrast agent application), the veins are investigated with color - and power Doppler to test visibility in comparison to the contrast agent investigation.

The goal of this initial proof of principle single arm cohort trial is to determine if contemporary endovascular venous intervention, compared with a 1:1 propensity-matched medical therapy arm of the ATTRACT trial, significantly reduces the 2-year occurrence of Post Thrombotic Syndrome (PTS) in subjects with symptomatic proximal Deep Vein Thrombosis (DVT).

An estimated 22% of the global population is at an increased risk of a severe form of COVID-19, while one in four coronavirus patients admitted to intensive care unit will develop a pulmonary embolism. A major public health question remains to be investigated: why COVID-19 is mild for some, critically severe for others and why only a percentage of COVID-19 patients develop thrombosis, despite the disease's proven hypercoagulable state? Patients' intrinsic characteristics might be responsible for the deep variety of disease forms. Our study aims to assess the validity of the hypothesis according to which underlining genetic variations might be responsible for different degrees of severity and thrombotic events risks in the novel coronavirus disease. Moreover, we suspect that prothrombotic genotypes occuring in the genes that encode angiotensin-converting enzyme (ACE-DEL/INS) and angiotensinogen (AGT M235T) are involved in the unpredictable evolution of COVID-19, both in terms of severity and thrombotic events, due to the strong interactions of SARS-CoV-2 with the renin-angiotensin-aldosterone system (RAAS). Therefore, we also aim to assess the validity of the theory according to which there is a pre-existing atypical modulation of RAAS in COVID-19 patients that develop severe forms and/or thrombosis. Our hypothesis is based on various observations. Firstly, there is a substantial similarity with a reasonably related condition such as sepsis, for which there is a validated theory stating that thrombophilic mutations affect patients' clinical response. Secondly, racial and ethnic genetic differences are responsible for significant dissimilar thrombotic risks among various nations. Thirdly, an increase in stroke incidence has been reported in young patients with COVID-19, without essential thrombosis risk factors, favoring the idea that a genetic predisposition could contribute to increase the thrombotic and thromboembolic risk. Fourthly, the plasminogen activator inhibitor (PAI)-1 4G/5G inherited mutation was found to be responsible for a thrombotic state causing post-SARS osteonecrosis.

DESTINY D-Dimer is an observational feasibility study, and a collaboration between the University of South Wales and Cwm Taf Morgannwg University Health Board (CTMUHB). The study is based at St. John's Medical Practice in Aberdare, where participant recruitment will take place. Blood D-dimer data will be collected from CTMUHB Pathology Laboratory services, at Prince Charles Hospital. Study blood samples will be obtained by the research student, LAH, under the direction of Dr Owen Thomas at St John's Medical Centre. The participant data will be collected by the research student who will conduct a Wells' Risk Score and perform D-dimer POC tests to generate quantitative data. Data will later be compared by the research student with the diagnoses obtained from Secondary Care at Prince Charles Hospital via analysis of medical records to include a laboratory generated D-Dimer results and additional diagnostics (eg. Doppler). A laboratory based analytical verification of D-dimer POC tests will be undertaken to compare with the current laboratory method. The study will compare the data from the D-dimer POC tests and those gained using laboratory methods at Prince Charles Hospital.

Patients with COVID-19 in the Intensive Care Unit (ICU) or hospitalized with severe form have a poor prognosis (almost 30% rate of death). They present often a high cardiovascular risk profile (almost 30% of hypertension and 19% of diabetes). Troponin has been described to be elevated in a high proportion of patients (one fifth of all patients and 50% of non-survivors) suggesting the possibility of cardiomyopathies. High levels of DDimers (81% of non survivors) and fibrin degradation products are also associated with increased risk of mortality suggesting also the possibility of venous thromboembolism. Therefore, screening for cardiomyopathies and venous thromboembolism could represent an important challenge for patients with COVID-19 management.

Portal vein thrombosis (PVT) is defined as an obstruction of the portal vein. The prevalence of PVT is 10-25% and incidence is about 16% in cirrhotic patients. PVT leads to increased intrahepatic resistance, decreased portal velocities, splanchnic vasodilatation, and stagnant flow. Portal vein recanalization (PVR) with transjugular intrahepatic portosystemic shunt (TIPS) is aimed at restoring main portal vein (PV) flow in chronic PVT. In this study, we will review the safety and outcomes of this approach.

The aim of this study is to estimate the incidence of spontaneous and provoked recurrent VTE and the bleeding events during a 10-year follow-up in subjects experiencing a first VTE stratified according to % AT levels and to treatment schedule (long-term vs 6-12 months oral anticoagulation+transient prophylaxis during high risk periods)

This prospective controlled study examines the use of Doppler ultrasound as a means to screen elective plastic surgery patients for the presence of deep venous blood clots both before and after surgery. This is a noninvasive technique that is known to be both sensitive and specific for the detection of deep venous thromboses in the lower extremities. This method may make it unnecessary to select patients for prophylactic anticoagulation, which poses additional risks to the patient.

The Crux Vena Cava Filter (VCF) Registry is a clinical study, sponsored by Volcano Corporation, to evaluate the short and long term performance and clinical outcomes of the Crux Vena Cava Filter System.