Clinical Research Directory

Replication of the EINSTEIN-DVT Anticoagulant Trial in Healthcare Claims Data

Investigators are building an empirical evidence base for real world data through large-scale replication of randomized controlled trials. The investigators' goal is to understand for what types of clinical questions real world data analyses can be conducted with confidence and how to implement such studies.

Aspiration Thrombectomy Using the Symphony or Prodigy System

The study is designed to evaluate the short-term and long-term clinical performance and safety of the Symphony and Prodigy thrombectomy systems used in endovascular procedures across the peripheral or pulmonary vasculature.

Timing of Thromboprophylaxis After Postpartum Hemorrhage

Postpartum hemorrhage is a leading cause of maternal morbidity and mortality worldwide. Women who experience severe postpartum hemorrhage are at increased risk of both recurrent bleeding and venous thromboembolism. The optimal timing for starting pharmacological thromboprophylaxis after postpartum hemorrhage remains uncertain. This retrospective observational cohort study was conducted at the Center of Maternity and Neonatology of Tunis, Tunisia. The study included women who experienced postpartum hemorrhage between 2018 and 2024 and received pharmacological thromboprophylaxis during the postpartum period. The objective was to evaluate the association between the timing of thromboprophylaxis initiation and the occurrence of thromboembolic and hemorrhagic complications. The findings are expected to contribute to the optimization of thromboprophylaxis timing after postpartum hemorrhage and to improve the balance between the prevention of venous thromboembolism and the risk of recurrent bleeding.

The Protrieve PROTECTOR Study

The Protrieve PROTECTOR Study is a prospective, single-arm, multicenter study of the Protrieve Sheath.

An Observational Study in the United States to Learn How Venous Thromboembolism, Disseminated Intravascular Coagulation, and Sepsis Are Related

This is an observational study in which data already collected from people with venous thromboembolism (VTE) due to sepsis (blood poisoning) are studied. These people were hospitalized in an intensive care unit (ICU) and may or may not have had disseminated intravascular coagulation (DIC). In this observational study, only observations are made without participants receiving any advice or changes to their healthcare. VTE is a condition that occurs when blood clots form in the veins, which can be dangerous. DIC is a serious blood disorder that can cause clots throughout the body, blocking blood flow. People who have sepsis are at a higher risk of developing both VTE and DIC. Researchers wanted to know if people who have sepsis developed DIC before developing VTE. To prevent VTE in people with sepsis, it is important to know how severe the sepsis is, how it progresses, and whether DIC is also present or not. In this study, researchers will assess patient data from a medical database in the United States (US). The main purpose of this study is to learn if there is a relationship between sepsis, DIC, and VTE. To do this, researchers will divide the participants with VTE due to sepsis into three groups as follows: * participants who were diagnosed with DIC based on the extent of blood clotting * participants who likely had DIC but it was not diagnosed * participants who did not develop DIC during the same hospital visit The researchers will collect the following information: * the number of participants who had VTE due to sepsis also had DIC * the change in participants' laboratory results and vital signs, such as heart rate and blood pressure, from the time their sepsis was diagnosed to the time their VTE and DIC were diagnosed The researchers will study the data collected between January 2007 and December 2021. The data will come from the participants' information stored in a database called the Optum VTE EHR which collects patient medical data from hospitals across the US. In this study, only available data from routine care are collected. No visits or tests are required as part of this study.

A Study to Observe the Pattern of Use and Safety of Rivaroxaban in Children Under 2 Years Old With Venous Thromboembolism (VTE)

This is an observational study in which only data are collected from participants receiving their usual treatment. The study is done in children under 2 years old with venous thromboembolism (VTE). VTE is a condition in which blood clots form in the veins, usually in the leg. This can cause pain and swelling. The clot can also break apart and travel in the blood to the lungs where it can block the blood flow. This can be life threatening. Rivaroxaban is approved for doctors to prescribe to children with VTE, but there is limited information about how it is used, how well it works, and how safe it is in children under 2 years old. Children in this study are already receiving or will receive rivaroxaban or other currently used medicines for VTE from their doctor according to the approved product information. The purpose of this study is to collect information on the pattern of use and safety of rivaroxaban and other standard medicines for VTE in children under 2 years old. The main information that researchers will collect in this study: * Age, gender, and other information about the child and their illness * Type of VTE treatment given to the child * Occurrence of medically important bleeding and its severity Further information that researchers will collect: * Changes in the characteristics of the children given VTE treatment (e.g., changes in the age range of children given VTE treatment) and changes in the treatment pattern for VTE * Return of VTE symptoms * Types of doctors who prescribe VTE treatment and their set-up (e.g., special clinics versus hospitals) Besides this data collection, no further tests or examinations are needed in this study. The data for this study will be collected from electronic health records and health insurance claims data until 2026. Researchers will observe each child during treatment until: * end of the anticoagulation treatment period e.g. discontinuation of all study drugs, * their information is no longer available, or * the study ends.

DEFIANCE: RCT of ClotTriever System Versus Anticoagulation In Deep Vein Thrombosis

This study is a prospective, multicenter, randomized controlled trial of an interventional strategy using the ClotTriever System to achieve and maintain vessel patency (ClotTriever Intervention Arm) versus conservative medical management using anticoagulation therapy alone (Conservative Medical Management Arm) in the treatment of subjects with symptomatic unilateral iliofemoral DVT. The study will collect data on demographics, comorbidities, details from the DVT diagnosis and treatment, and clinical outcomes through the 6-month follow up visit.

RIVAroxaban Versus Low-molecular Weight Heparin in Patients With Lower Limb Trauma Requiring Brace or CASTing

Lower limb trauma requiring immobilization is a very frequent condition that is associated with an increased risk of developing venous thromboembolism (VTE). The TRiP(cast) score has been developed to provide individual VTE risk stratification and help in thromboprophylactic anticoagulation decision. The recent CASTING study had confirmed that patients with a TRiP(cast) score \<7 have a very low risk of VTE and could be safely manage without prophylactic treatment. Conversely, patients with a score ≥ 7 have a high-risk of VTE and require a prophylactic anticoagulant treatment. Low molecular weight heparins (LMWH) have been shown to be effective in this indication. However, in the CASTING study, the 3-month symptomatic VTE rate was 2.6% in this subgroup despite LMWH prophylactic treatment. This result suggests that LMWH are not sufficiently effective in this particular subgroup of high-risk patients. Direct oral anticoagulants, and in particular rivaroxaban, may be an effective and safe alternative to LMWH. In the PRONOMOS study, comparing LMWH with rivaroxaban in patients who had undergone non-major lower limb surgery, the relative risk of symptomatic VTE was 0.25 (95% CI = 0.09 - 0.75) in favor of rivaroxaban 10mg. No significant increase in bleeding was found. In addition, as LMWH treatment requires subcutaneous daily injections, the use of rivaroxaban may positively impact patients' quality of life as well as being effective in medico-economic terms. The aims of this study are to demonstrate that rivaroxaban is at least as effective, easier to use and more efficient than LMWH in patients with trauma to the lower limb requiring immobilisation and deemed to be at risk of venous thromboembolism (TRiP(cast) score ≥ 7). High-risk patients are randomized to receive either rivaroxaban or LMWH. They are followed up at 45 days and 90 days to assess the occurrence of thrombotic events or bleeding, as well as their satisfaction with the treatment received.

Comparison of Bleeding Risk Between Rivaroxaban and Apixaban for the Treatment of Acute Venous Thromboembolism

Apixaban and rivaroxaban have been compared to standard therapy for treatment of acute symptomatic venous thromboembolism (VTE) in randomized controlled trials (RCTs), and are both approved by Health Canada. No safety or efficacy data is available from direct head-to-head comparison of these two anticoagulants. Lawsuits in the United States over bleeding events, patient perceptions, and concerns with medication adherence are additional factors highlighting the importance of a comparison trial. This multi-center, pragmatic, prospective, randomized, open-label, blinded end-point (PROBE) trial aims to compare the safety of apixaban and rivaroxaban for the treatment of VTE.

Variations in the Hemostatic System Induced by a Standardized Walking Test

Two groups of patients will be compared: One group of patients with a history of venous thromboembolic disease and one group without. Both groups will be subjected to a walking test and with electrocardiogram measurements and blood tests.

VTE Prevention Following Total Hip and Knee Arthroplasty

Consented patients undergoing elective total hip and total knee arthroplasty will be randomized to receive either aspirin alone or aspirin and rivaroxaban for prevention of venous thromboembolism.

Residual Pulmonary Vascular Obstruction Index Computed With Ventilation/Perfusion SPECT/CT Imaging to Predict the Risk of Venous Thromboembolism Recurrence in Patients With Pulmonary Embolism (PRONOSPECT)

Major risk after pulmonary embolism (PE) is recurrence, fatal in 10% of patients. Patients with PE can be stratified in 3 groups according to the risk of recurrence : very low risk, high risk or Intermediate risk. Little is known about this last group. Anticoagulation is efficient to prevent recurrence but is currently not recommended for patient with an intermediate risk of recurrence. Identifying risk factors of recurrent PE remains a major issue to identify sub-groups of patients who would require lifelong anticoagulation. In 30-40% of cases, PE patients develop residual pulmonary vascular obstruction (RPVO), which has been found to be associated with an increased recurrence risk. This last observation was mostly reported in patients with unprovoked PE (patients with high risk of recurrence) and RPVO was measured using conventional planar lung scan. In patients with an intermediate risk of recurrence, the impact of RPVO has been much less studied. In addition, the definition of RPVO was variable according to studies and correlation between RPVO burden and recurrence risk has not been clearly demonstrated. This might be explained by the inherent limitation of RPVO quantification using conventional planar imaging, which is only based on a visual estimation on 2-dimensional images. Ventilation/Perfusion Single Photon Emission Computed Tomography (V/Q SPECT/CT) is a new method of scintigraphic image acquisition that offers the advantage of 3-dimensional imaging, enabling more accurate and reproducible quantification of RPVO. The main hypothesis of this study is that in patients with PE at intermediate risk of recurrence, RPVO computed with V/Q SPECT/CT imaging may be an important predictor of recurrence.

Statins to Prevent Cancer Associated Blood Clots

Patients with cancer are at high risk for life-threatening venous thromboembolism (VTE) yet rarely receive anticoagulant prophylaxis due to bleeding risks. Thus, effective prophylaxis in oncology requires a method to reduce VTE without increasing hemorrhage. The primary aim of the Statin Therapy to Prevent Cancer Associated Venous Thromboembolism (STAT-CAT) trial is to test whether rosuvastatin 20 mg daily for 12 months compared to placebo can safely prevent VTE in patients with newly diagnosed or recently relapsed cancer who are at increased thrombotic risk, are not planned to be anticoagulated, and who do not otherwise take statin therapy.

Venous Thrombosis Biomarkers in Sickle Cell Disease and Sickle Cell Trait

Background: Venous thromboembolism (VTE) includes the abnormal clotting of blood in a deep vein of the upper or lower limbs (deep vein thrombosis) that may travel to and block a blood vessel in the lung (pulmonary embolism). Some people with sickle cell disease (SCD)-a red blood cell disorder-seem to be at greater risk for developing these blood clots. Researchers want to study the blood of people with SCD and VTE as well as healthy people to develop better treatments to prevent blood clots. Objective: To study blood clotting in SCD because it is the most common cause of vascular death after a heart attack or stroke. Eligibility: People ages 18-80 who have SCD (with or without a history of blood clots) or the trait for SCD, and healthy volunteers Design: Participants will be screened with medical history, physical exam, and medical records review. They will give blood samples. Participants will have phone calls either every 3 months or once a year, for 2 years. They will give updates on their health. They may give additional medical records. The phone calls may last up to 30 minutes. If participants have a VTE or pain crisis episode, they may visit the Clinical Center. These visits may last up to 4 hours. They will repeat the screening tests and give blood samples. Some participants may be invited to take part in blood studies. After 2 years, some participants will have a follow-up visit at the Clinical Center. Participation will last for about 2 years.

A Performance Evaluation of the LumiraDx Point Of Care D-dimer Assay

In patients with symptoms of Venous Thromboembolism (VTE) (mainly deep vein thrombosis (DVT) or pulmonary embolism (PE)), the study will evaluate the agreement between the D-Dimer measurements from the LumiraDx POC D-Dimer assay and a reference method, as an aid in diagnosis, assessment and exclusion of DVT and PE.

THRomboprophylaxis in Individuals Undergoing Superficial endoVEnous Treatment (THRIVE)

Endovenous interventions are keyhole operations for varicose veins that are carried out from within the vein itself. Varicose veins are enlarged veins close to the surface of the skin. They are connected to the bigger deeper veins in the leg (known as deep veins). Because of this, operations to close the varicose veins can increase the chance of a blood clot forming in the deep veins. Blood clots in the deep veins happen in around 1 in 50 people after endovenous operations. A clot in the leg can cause swelling, pain, and other long-term problems. If a clot in the leg breaks off and travels to the lungs, it can cause problems with the lung' ability to move oxygen from the air into the blood and may, in rare cases, be life threatening. Varicose vein procedures may carry a slightly higher risk of blood clot formation, and we are currently unsure if current clot reducing medicines are beneficial in preventing blood clots in people having varicose vein procedures. This study will investigate if it is worthwhile prescribing medicines to reduce blood clots after varicose vein procedures.

A Study in the United Sates That Looks at the Safety and Effectiveness of Pradaxa Pellets in Children Aged 3 Months to Less Than 12 Years Who Need Treatment of a Blood Clot or Who Have Had a Blood Clot and Are at Risk of Developing Another Blood Clot

The main research question of this study is to obtain further safety and effectiveness data on Pradaxa Pellets in children aged 3 months to less than 12 years in routine clinical practice setting.

People's Hospital of Xinjiang Uygur Autonomous Region

Objective: To evaluate the impact of enhanced recovery after surgery (ERAS)-based nursing intervention on venous thromboembolism (VTE) and lymphedema after radical hysterectomy for cervical cancer. Methods: In this prospective randomized controlled trial, 160 patients scheduled for radical hysterectomy during September 2022-September 2024 were randomized to an ERAS group (n = 80) or a control group (n = 80). The control group received conventional perioperative care, while the ERAS group received a multimodal perioperative care protocol. Primary outcomes were the 6-month incidence of VTE and lower limb lymphedema. Secondary outcomes included recovery indicators, inflammatory and coagulation markers, quality of life \[QoL; assessed by the Quality of Life Questionnaire-Core 30 (QLQ-C30)\], and nursing satisfaction.

A Trial to Learn How Well REGN7508 Works for Preventing Blood Clots After a Knee Replacement in Adult Participants

This study is researching an experimental drug called REGN7508 (called "study drug"). The study is focused on adults undergoing elective, unilateral (one side) total knee replacement (TKR) surgery. The aim of the study is to see how effective the study drug is at preventing venous thromboembolism (VTE) and other related diseases after unilateral total knee replacement surgery. The study is looking at several other research questions, including: * What side effects may happen from taking the study drug * How much study drug is in the blood at different times * Whether the body makes antibodies against the study drug (which could make the drug less effective or could lead to side effects)

Clinical Surveillance vs. Anticoagulation for Low-risk Patients With Isolated Subsegmental Pulmonary Embolism

The clinical significance of pulmonary embolism (PE) limited to the subsegmental pulmonary arteries, so called isolated subsegmental pulmonary embolism (SSPE), remains controversial. Whether isolated SSPE represents "true" PE, a clinically more benign form of PE, a physiologic lung clearing process, or a false positive result (artifact) is currently unclear and hence, whether patients with isolated SSPE benefit from anticoagulant treatment is uncertain. Despite growing evidence from observational studies that withholding anticoagulation may be a safe option in selected patients with isolated SSPE (i.e., those without concomitant deep vein thrombosis, cancer, etc.), most patients with isolated SSPE receive anticoagulant treatment, which is associated with an increased risk of bleeding. The overall objective of the randomized controlled SAFE-SSPE trial is to evaluate the efficacy and safety of clinical surveillance without anticoagulation compared to anticoagulation treatment in low-risk patients with isolated SSPE.

Development and Validation of an Interpretable Machine Learning Model for Predicting Venous Thromboembolism（VTE）in Intensive Care Unit (ICU) Patients

Venous thromboembolism remains a leading cause of preventable mortality in intensive care unit (ICU) patients. Existing risk-stratification tools were developed in general medical populations and lack ICU-specific predictors. This study was to develop and validate an interpretable machine learning (ML) model to predict VTE in ICU patients.

Prediction of Venous Thrombosis During chemotherapy-the PINPOINT Study

Cancer patients are at higher risk of getting a blood clot (known as venous thromboembolism (VTE)) especially during chemotherapy and some patients are more at risk than others. These clots can be prevented by using blood thinners (known as anticoagulants) but these are not suitable for everyone as they also carry a risk of bleeding. This study aims to identify which chemotherapy patients are most at risk of a blood clot and at what point in their treatment this is likely to happen. In this project biomarkers in the blood that are involved in blood clotting will be measured in cancer patients at four stages during chemotherapy to see how the biomarkers change during treatment. The blood samples for these tests are taken at the same time as the normal routine blood tests done before a chemotherapy cycle. Biomarker levels will be compared between those patients who subsequently get a VTE and those who do not get a VTE. This will help develop a biomarker based blood test to predict clots during chemotherapy. The biomarker based test will also be compared with other methods of predicting VTE in cancer patients which are currently in use. In the future, this blood test might be used to see if patients are at high risk of a clot during chemotherapy and provide a method to optimise the use of preventative anticoagulants in cancer patients during chemotherapy.

An Observational Study to Learn More About How Safe Treatment With Rivaroxaban is in Children in Japan With Venous Thromboembolism

This is an observational study in which only data will be collected from children with venous thromboembolism who are prescribed rivaroxaban or warfarin by their doctors. Venous thromboembolism (VTE) is a condition in which people have problems due to the formation of blood clots in their veins. The study drug rivaroxaban is an approved treatment for VTE in children and adults in Japan. It is a blood thinner that prevents the blood from clotting by blocking a protein responsible for blood clotting. Warfarin is another blood thinner that is available for VTE. In this study warfarin is the reference drug. A previous study was carried out to learn about how well rivaroxaban works and how safe it is in children with VTE. However, to better understand the safety of this drug in children, more knowledge is needed about the use of rivaroxaban in the real world. The main purpose of this study is to learn more about the occurrence of major bleeding in children taking rivaroxaban. Major bleeding can be bleeding within the skull, bleeding inside the eye, bleeding from an organ in the digestive system, or bleeding which requires being given blood from a donor. In addition, this study will help learn more about the following in children with VTE: * The occurrence of major bleeding during treatment with rivaroxaban and during treatment with warfarin * The occurrence of bleeding of importance in children being treated with rivaroxaban and in children being treated with warfarin. Bleeding of importance in children can be: bleeding from the lung, blood in the kidney, heavy menstrual bleeding * The occurrence of major bleeding and bleeding of importance in children who are taking drugs called anti platelet agents and NSAIDs to prevent blood clots at the same time as rivaroxaban, who are taking a drug that blocks the action of a protein called 'CYP3A4' at the same time as rivaroxaban, who have reduced kidney function, who have taken rivaroxaban for a long time, or who have taken other drugs by mouth to prevent blood clots before starting rivaroxaban * The occurrence of repeated VTE on treatment with rivaroxaban and on treatment with warfarin The children with VTE in this study are already receiving rivaroxaban or warfarin treatment as part of their regular care from their doctors. The data will come from an electronic health records database created by a company called Medical Data Vision. The data will be collected between January 2021 and June 2024. Researchers will look at the health information from children less than 18 years of age with VTE in Japan who are prescribed treatment with rivaroxaban or warfarin during the study period. In this study, only available data from routine care are collected. No visits or tests are required as part of this study

The Role of Platelet TLRs in Platelet Activation During VTE

Venous thromboembolic disease (VTE) is a frequent and potentially serious pathology. Therapeutic management has improved considerably over the last few decades, enabling the application of codified management in line with the recently updated French management recommendations. One of the main remaining difficulties concerns VTE sequelae, mainly post-thrombotic syndrome after deep vein thrombosis, and post-pulmonary embolism syndrome after pulmonary embolism. The mechanisms leading to the absence of complete repermeabilization of vessels affected by Venous thromboembolic disease (VTE) are still poorly understood. The concept of immunothrombosis, closely associating immunity, inflammation and thrombosis, could (in part) explain the appearance of these sequelae. Platelets appear to play a key role in the onset of sequelae: Platelets are known to be involved both in the onset of a VTE episode and in the inflammatory response. This involvement is illustrated by the expression of inflammatory receptors such as TLR (toll-like receptor) 2 and TLR4. Th aim to investigate the role of platelets in the occurrence of sequelae, mainly via their role in the inflammatory response, in Venous thromboembolic disease (VTE) patients.