Clinical Research Directory

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.

LMWH vs Aspirin for VTE Prophylaxis in Orthopaedic Oncology

Aspirin and low molecular weight heparin (LMWH) are both commonly employed pharmacologic methods of venous thromboembolism (VTE) prophylaxis after orthopaedic surgery. Data comparing these two methods of VTE prophylaxis in patients undergoing pelvic/lower extremity orthopaedic surgery for malignancy are lacking, however, as compared to the data and guidelines present for VTE chemoprophylaxis after joint arthroplasty and hip fracture surgery. In this clinical trial, our specific aim is to compare the post operative incidence of VTE between patients receiving aspirin and LMWH after pelvic/lower extremity orthopaedic oncology procedures.

Antithrombin to Improve Thromboprophylaxis and Reduce the Incidence of Trauma-Related Venous Thromboembolism

The purpose of this study is to determine if additional interventions will assist with decreasing the risk and/or severity of thromboembolism (clotting complications) in patients who have experienced a major traumatic event.

The Protrieve PROTECTOR Study

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

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.

Evaluation of the SCALED (SCaling AcceptabLE cDs)

This project will adapt a currently deployed Clinical Decision Support (CDS) system to deliver a VTE prevention guideline for adult patients with traumatic brain injury (TBI). We believe this is an ideal PCOR use case given PCORI's continued effort to combat VTE in trauma and our experience previously implementing this guideline. The Our overall goal is to successfully scale, evaluate, and maintain an interoperable TBI CDS across 7 total institutions.

Comparison of Thrombin Generation, Platelet Activation and Aggregation Profiles in Patients With Sickle Cell Disease Depending on Their SS or SC Genotype (DrepAgreg)

Sickle cell disease (SCD) is characterized by chronic hemolytic anemia, painful crises called vaso-occlusive crises (VOC) and chronic inflammation. Activated platelets from SCD patients contribute to both chronic inflammation and painful VOC. Individuals with the HbSC genotype experience anemia and less severe clinical manifestations than those with the HbSS genotype; however, they are at higher risk of venous thromboembolic events, particularly pulmonary embolism. This study aims to investigate whether sickle cell patients exhibit different thrombin generation profiles as well as distinct platelet activation and aggregation profiles, depending on their SS or SC genotype.

Computerized Decision Support for Prevention of VTE in Hospitalized Medical Patients Across the Continuum of Care (DC-eALERT)

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.

Comparison of Bleeding Risk Between Rivaroxaban and Apixaban: The Pilot Study

This vanguard pilot study compares rivaroxaban and apixaban, two of the new oral blood thinners for the treatment of blood clots. Half of the patients will receive apixaban and half will receive rivaroxaban. The main objective is to determine the feasibility of patient recruitment and resources required to follow enrolled patients and inform for a larger, multi-centered trial and to assess which one is safer.

Computerized Registry of Patients With Venous Thromboembolism (RIETE)

The Computerized Registry of Patients with Venous Thromboembolism (RIETE) is a multidisciplinary Project initiated in march 2001 and consisting in obtaining an extensive data registry of consecutive patients with venous thromboembolism. The main objective is to provide information on the Internet to help physicians to improve their knowledge on the natural history of thromboembolic disease, particularly in those subgroups of patients who are usually not recruited in randomized clinical trials (pregnant women, elderly patients, disseminated cancer, severe renal insufficiency, patients with contraindications to anticoagulation therapy, extreme body weight, etc), with the purpose of decreasing mortality, frequency of thromboembolic recurrences as well as bleeding complications and arterial events. As an additional objective RIETE is also aimed to create predictive scores that help physicians to better identify patients with high risk of presenting some of these complications. The primary parameters recorded by the registry comprise details of each patient's clinical status, including any coexisting or underlying conditions, and the type, dose, duration and outcome (during the first 3 months of therapy) of antithrombotic treatment. Study endpoints are clinically recognized (and objectively confirmed) recurrences of VTE, major and minor bleeding complications, and death.

Secondary Prevention of VTE in Patients With Cancer and Catheter-Related Upper Extremity Deep Vein Thrombosis

This trial seeks to evaluate a management strategy after the acute treatment duration (≥ 3 months of therapeutic anticoagulation) for patients with cancer and catheter-related upper extremity deep vein thrombosis (DVT).

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.

Glioblastoma Remote Monitoring and Care - Research Protocol

The purpose of this research is to learn more about how what the Apple watch measures, in terms of walking data, heart rate, breathing rate, and sleep habits, relates to how participants feel. During the course of the treatment, the symptoms participants experience change, and whether the Apple watch can detect these changes. Ultimately, this knowledge is being used to design proactive tools and signatures that can predict complications or symptom changes before they happen.

Smart Technology Facilitated Patient-centered Care for Patients With Pulmonary Thromboembolism

Smart technologies, such as wearable devices, mobile technologies, and artificial intelligence, are being investigated for use in health management. These technologies have the potential to be applied in disease pre-warning, decision-making support, health education, and healthcare maintenance. They are expected to address the challenges in managing thrombosis, improve access to high-quality medical resources in various regions, and enhance the development of a network for thrombosis rescue and treatment prevention. This study aims to evaluate the effects of a smart technology-assisted, patient-centered mobile health application for pulmonary thromboembolism management (mPEA) on the long-term outcomes of patients with pulmonary thromboembolism (PTE). The findings are expected to inform clinical practice and provide an evidence base for the long-term management of patients with PTE.

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.

Intervention to Improve Utilization of Extended Venous Thromboembolism Prophylaxis After Cancer Surgery

While blood clots after major cancer surgery are common and harmful to patients, the medications to decrease blood clot risk are seldom used after patients leave the hospital despite the recommendation of multiple professional medical societies. The reason why these medications are seldom prescribed is not well understood. The main questions this study aims to answer are: * Does surgeon education paired with an electronic medical record based decision support tool improve the guideline concordant prescription of pharmacologic venous thromboembolism after abdominopelvic cancer surgery? * Does dedicated patient education regarding blood clots at the time of hospital discharge after abdominopelvic cancer surgery improve understanding of the risk of venous thromboembolism and adherence to pharmacologic prophylaxis? The investigators will study these questions using a stepped-wedge randomized trial where groups of surgeons will use a tool integrated to the electronic medical record to educate them on the individualized patient risks of blood clots after major cancer surgery and inform them regarding guidelines for preventative medicines. Utilization of the medications before and after using the tool will be compared. Patients will be administered a questionnaire assessing their awareness of blood clots as a risk after cancer surgery. For those prescribed medications to reduce blood clot risk after leaving the hospital, the questionnaire will evaluate whether they took the medications as prescribed. Survey results will be evaluated before and after implementation of education on blood clot risk at the time of hospital discharge.

inDividual, Targeted thrombosIS Prophylaxis Versus the Standard 'One Size Fits All' Approach in Patients Undergoing Total hIp or Total kNee replaCemenT

After hip or knee replacement all patients receive a standardized treatment with blood thinners, this medication is called thrombosis prophylaxis. However, despite this standard treatment some individuals still develop venous thrombosis (VTE), while others experience bleeding. This indicates that not all patients have the same VTE risk following surgery. Individualizing the amount of thrombosis prophylaxis following surgery might lead to less thrombotic and bleeding events. In this study the investigators individualize the treatment with thrombosis prophylaxis based on the medical history of a patient. The main questions this study aims to answer are: Can thrombosis prophylaxis be shortened in patients with a low VTE risk to decrease the risk of bleeding without increasing the risk of VTE? Does an increase in the dose and duration of thrombosis prophylaxis in patients with a high VTE risk reduce the risk of VTE without inducing an unacceptable risk of bleeds? Researchers will compare both the shortened treatment in low VTE risk patients and the intensified and extended treatment in high VTE risk patients with the standard treatment to assess the risk of VTE and bleeding in comparison to the standard treatment. Participants will receive 4 questionnaires to evaluate whether they have experienced a VTE or bleed. For this study no additional hospital visits are necessary.

Prognostic Value of 2026 AHA/ACC Clinical Categorization in Acute Pulmonary Embolism Patients Presenting to the Emergency Department

Background: The 2026 American Heart Association/American College of Cardiology (AHA/ACC) Pulmonary Embolism Guideline (Creager et al., Circulation 2026) introduced a novel five-category (A-E) clinical classification system with subcategories and an R modifier, replacing prior risk stratification frameworks. Prospective validation of this classification system using composite clinical outcomes is lacking. Objective: To evaluate the prognostic value of the 2026 AHA/ACC clinical categorization (Categories A-E plus R modifier) for predicting 30-day Major Adverse Pulmonary Embolism Events (MAPEE) in emergency department (ED) patients with acute pulmonary embolism (PE). Methods: Prospective observational cohort study conducted at Marmara University Faculty of Medicine Emergency Department, enrolling 600 consecutive adult patients with confirmed acute PE by computed tomography (CT) pulmonary angiography between April 2026 and January 2027. Primary outcome: MAPEE composite (all-cause mortality OR hemodynamic deterioration OR treatment escalation OR cardiopulmonary resuscitation) within 30 days. Secondary outcomes include area under the receiver operating characteristic curve (AUC) comparison with the European Society of Cardiology (ESC) 2019 risk stratification (exploratory), negative predictive value (NPV) of low-risk categories (A+B) for safe discharge, MAPEE trend across C1/C2/C3, and R modifier odds ratio. Statistical analysis: Jamovi v2.x. Reporting follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) 2007 checklist.

Impact of COVID-19 Vaccines on Cerebrovascular Health

Safe and effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines may reduce the transmission of and achieve population immunity against the COVID-19 pandemic, which accounted for more than 3.75million deaths worldwide. With World Health Organization's (WHO) effort on ensuring equitable access to COVID-19 vaccines, vaccination rate may increase in the near future. On the other hand, vaccination hesitancy has emerged as a major hindrance on the global vaccination campaigns in certain areas due to safety concerns, social factors, and public health policies. For instance, a recent survey conducted in Hong Kong showed a low vaccine acceptance rate of 37%. Long-term safety concerns and post-vaccination events relayed by the social media maybe reasons for vaccination hesitancy. Among which, cerebrovascular accidents (CVA) after vaccination were one of the most frequently reported post-vaccination events. These reports ranged from ischemic strokes in elderly patients with multiple cardiovascular co-morbidities, to hemorrhage strokes in otherwise "young-and-fit" adults. While many of these events were investigated by the COVID-19 immunization expert committee, an important premise to address the apprehension of CVA after vaccination is the provision of evidence-based information of the impact of COVID-19 vaccines on brain health. In this prospective, longitudinal, observational study, we aim to elucidate the relationship between COVID-19 vaccines and cerebrovascular health in healthy citizens in a population-based cohort.

DOAC in Chinese Patients With Atrial Fibrillation

Direct oral anticoagulants (DOACs) have emerged as safe and efficacious ischemic stroke prophylaxis for non-valvular atrial fibrillation (NVAF). All four DOACs - apixaban, dabigatran, edoxaban, and rivaroxaban - were shown to reduce the risk of major bleeding compared to warfarin. The predictable pharmacokinetic profiles of DOACs also favour their use over warfarin. Together with increasing AF incidence due to population ageing, increased AF detection, and territory-wide reimbursement schemes, DOAC prescriptions have been surging worldwide. In Hong Kong, more than 78,354 patients received DOAC from January 2009 through April 2021 according to the Hospital Authority registry. The more liberal use of DOACs has led to new issues that require a thorough understanding of ethnic-specific DOAC pharmacokinetic profiles. For instance, 12- 15% of anticoagulated patients annually required interventional procedures that involve temporary discontinuation of DOAC for 48 hours or more. Although guideline-based periprocedural DOAC interruption resulted in a low 30-day thromboembolism rate of 0.16% - 0.6% in a Caucasian cohort, same measures for elective colonoscopies in a local population-based study resulted in a 30-day periprocedural thromboembolism rate of up to 2.2%. Although these studies cannot be compared directly, the remarkable interethnic discrepancy between the two cohorts warrants further pharmacokinetic and pharmacogenomic studies. More importantly, quantifying residual DOAC levels during the interruption periods may imply on duration of periprocedural DOAC interruption, length of hospital-stay, and the risk of thromboembolic and bleeding complications. Mapping inter- and intra-individual variations in DOAC levels may also impact on the management of ischemic stroke among DOAC recipients. Epidemiological studies have shown alarmingly up to 13% of acute ischemic stroke patients were on anticoagulation prior to stroke onset with increasing number of DOAC. These patients received low rates of recanalization therapy due to apprehension of bleeding complications, thus compromised survival and neurological recovery. A prospective study that reveals Asian-specific DOAC pharmacokinetic profiles may inform cross-disciplinary, territory-wide periprocedural care and acute stroke intervention strategy for the rapidly expanding DOAC population.

The PARTUM Trial: Postpartum Aspirin to Reduce Thromboembolism Undue Morbidity

The goal of the PARTUM trial is to determine if taking low-dose aspirin daily for 6 weeks after delivery is similar (non-inferior) to usual care low-molecular-weight heparin injections to prevent venous thromboembolism (VTE: blood clots in the legs or lungs) for postpartum individuals with VTE risk factors.

Colchicine to Quench the Inflammatory Response After Deep Vein Thrombosis (The Conquer-DVT Pilot Trial)

This trial seeks to assess the feasibility of a full-scale, double-blind, placebo-controlled, randomized trial assessing whether low-dose colchicine (0.5 mg daily) reduces the risk of post-thrombotic syndrome (PTS) in patients with proximal lower extremity deep vein thrombosis (DVT).

Reducing Gastrointestinal Bleeding With Proton Pump Inhibitor Therapy in Acute Venous Thromboembolism

The investigators are studying whether treatment with a proton pump inhibitor called omeprazole reduces gastrointestinal bleeding in older adults taking blood thinners for a blood clot (venous thromboembolism). The purpose of this study, a pilot study or a feasibility study, is to test the study plan and determine whether enough participants will join a larger study and accept the study procedures.

Pulmonary Embolism in Patients With Acute Heart Failure (PEHF Study)

This study focuses on two serious and common medical conditions: heart failure and pulmonary embolism (a blood clot in the lungs). Heart failure happens when the heart cannot pump blood effectively, and it is one of the main reasons older adults are admitted to the hospital. Pulmonary embolism can be life-threatening and may worsen heart failure or even trigger it. Doctors believe that pulmonary embolism may often go undetected in patients who come to the hospital with symptoms of acute heart failure, such as sudden shortness of breath. This is because both conditions can cause similar symptoms, making it difficult to tell them apart. As a result, doctors may sometimes assume the symptoms are only due to heart failure and not investigate further for a possible blood clot. However, missing a pulmonary embolism can have serious consequences. Studies suggest that some patients with heart failure who die may actually have had an undiagnosed pulmonary embolism. Current medical guidelines recommend checking for pulmonary embolism when the cause of breathing problems is unclear, but in real-life practice, this is not always done. The goal of this study is to find out whether pulmonary embolism is underdiagnosed in patients with suspected acute heart failure and whether systematically testing for it could improve patient outcomes. To do this, the study will compare two approaches in several hospitals. In half of the hospitals, doctors will follow their usual practice and decide case by case whether to test for pulmonary embolism. In the other half, doctors will systematically test all eligible patients for pulmonary embolism using recommended diagnostic methods. Adult patients admitted with recent or worsening breathing difficulties and signs of acute heart failure may be included in the study, provided they give their consent. Researchers will collect information about their symptoms, tests, diagnosis, and treatments. Patients will be monitored during their hospital stay and for three months afterward. The study will track important outcomes such as survival, new blood clots, bleeding events, repeated hospital visits for breathing problems, and overall time spent in the hospital. The researchers expect to include about 740 patients in total. They estimate that pulmonary embolism may be found in about 1% of patients with usual care, but up to 5% when doctors systematically look for it. This study aims to better understand how often pulmonary embolism occurs in patients with acute heart failure and whether more systematic testing could lead to earlier diagnosis and better care. The results could help improve medical practice and reduce complications or deaths related to missed diagnoses.