Real-time Anti-Factor Xa Measurements in Surgical Patients to Examine Enoxaparin Metabolism and...
Deep Venous ThrombosisPulmonary Embolus1 moreVenous thromboembolism (VTE) encompasses deep venous thrombosis and pulmonary embolus, and is the proximate cause of death in over 100,000 hospitalized patients per year. This project will critically examine the pharmacokinetics of prophylactic doses of enoxaparin in surgical patients, and will evaluate how alteration of enoxaparin dose magnitude and frequency affects peak and trough aFXa levels as well as risk for re-operative hematoma. If subtherapeutic aFXa levels are observed, the study will design, implement and test a clinical protocol to optimize post-operative aFXa levels. Although not an explicit Aim, this study will also provide important preliminary data on VTE rates in surgical patients with in range and out of range aFXa levels.
Screening for Occult Malignancy in Patients With Idiopathic Venous Thromboembolism
Venous ThromboembolismDeep Vein Thrombosis1 moreBlood clots in leg veins (deep vein thrombosis) or lung arteries (pulmonary embolism) that happen for no reason (i.e. unexplained) are both called "unprovoked venous thromboembolism" (VTE). These unexplained blood clots can be the first symptom of cancer. Up to 10% of patients with unexplained blood clots will be diagnosed with cancer within one year of their blood clot diagnosis. These cancers can be found anywhere in the body although the relationship appears stronger with the pancreas, ovary and liver. Cancer testing in patients with blood clots is controversial. There is presently a wide variety of expert opinions and practices. Previous studies showed that a limited cancer screen including a medical history, physical examination, basic blood work and chest X-ray, will find about 90% of cancers. More recent and better designed studies showed that the limited cancer screen misses many cancers and needs to be improved. More extensive cancer testing may find more cancers but is potentially uncomfortable for patients, costs a lot of money and involves a lot of people. The "comprehensive computed tomography" is less uncomfortable, inexpensive, radiological test made to find many cancers at once. Thus, the scientific question to be asked is: Does a "comprehensive computed tomography" miss less cancers than a limited cancer screen in patients with blood clots? The main goal of this study is to find out if a "comprehensive computed tomography" misses less cancers than a limited cancer screen in patients with unexplained blood clots. The second goal of the study is 1) to find out if a "comprehensive computed tomography" finds more "curable" cancers than the limited cancer screen; 2) to find out if the patients diagnosed with cancer are still alive and cancer-free after one year (i.e. the patients with curable cancer were treated and are doing well); 3) to prove that a negative "comprehensive computed tomography" means that the patient will not have cancer and; 4) to find out if a "comprehensive computed tomography" is well tolerated and safe for patients.
Safer Warfarin Treatment
Atrial FibrillationVenous Thrombosis2 moreThe study is a national multicenter prospective observational study, including 200 patients. The main purpose of this study is to explore in more detail the influence of genetic variability (CYP enzymes and vitamin K dependent proteins) and dietary vitamin K status on warfarin dosing, clinical effect and adverse events with emphasis on the initial phase of treatment. The hypothesis is that genetic variability concerning CYP enzymes and vitamin K dependent proteins predict dosing and adverse events during warfarin treatment. The main aim is to individualize warfarin therapy and establish a treatment algorithm based on genotype and dietary vitamin K status to make the anticoagulation therapy with warfarin more secure.
A Study to Evaluate the Efficacy and Safety of Fondaparinux for the Prevention of Venous Blood Clots...
ThrombosisVenousThe purpose of this study is to evaluate the efficacy and safety of fondaparinux in comparison with a heparin (nadroparin) in preventing deep vein thrombosis (blood clots in the leg veins), whether symptomatic or detected by ultrasound, and pulmonary embolism (blood clots that migrate to the lungs) in patients with leg injuries below the knee that require a cast or other type of immobilization but not surgery.
Full-Leg vs Below-Knee Elastic Stockings for Prevention of the Post-Thrombotic Syndrome
Deep Vein ThrombosisProspective controlled randomized clinical trial. Consecutive patients with acute proximal deep vein thrombosis of the lower extremities, with or without contemporary manifestations of pulmonary embolism, are randomized to receive either a below-knee or a full-leg graduated compression (30-40 mm Hg at the ankle) elastic stocking for prevention of the post-thrombotic syndrome (PTS). All patients are followed up to three years to assess the development of the PTS, defined according to a validated clinical score (the Villalta scale). The rate of PTS is compared between the two study groups. In addition, there is an assessment of patients' compliance and tolerability of the two different devices.
The STOP CLOT Pilot Study: Study of Low Molecular Weight Heparin in High Risk Cesarean Section
Deep Vein ThrombosisVenous thromboembolism (VTE) remains the most common cause of maternal death in the developed world. VTE includes two conditions, deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT refers to a blood clot that has formed in a deep vein, often in the legs and/or pelvis and PE refers to the passage of these clots into the lungs (which can be fatal). VTE is up to 10 times more common in pregnant women than non-pregnant women of comparable age. More than a third of pregnancy related VTE occur during the 6 weeks after delivery. When compared with vaginal delivery, cesarean delivery further increases the risk of pregnancy associated VTE by three-fold. A medication called low molecular weight heparin is sometimes prescribed during pregnancy and after delivery to prevent VTE. However, clinical practice varies because there hasn't been adequate research to determine that this medication is safe and effective at preventing VTE during this time. The potential benefits of the medication must also be weighed against its cost and possible side effects. The researchers are conducting a study that will assess the effectiveness and safety of low molecular weight heparin in women who are at moderate to high risk of VTE after a cesarean section. They will monitor these women to determine if those who received the medication have fewer blood clots. Participants will also be monitored closely for any side effects.
PROphylaxis for ThromboEmbolism in Critical Care Trial (PROTECT Pilot)
Critically IllDeep Venous ThrombosisPROTECT Pilot objective is to assess: 1) the feasibility of timely enrollment and complete, blinded study drug administration, 2) the bioaccumulation of LMWH in patients with acquired renal insufficiency and its association with bleeding, 3) the feasibility of scheduled twice weekly lower limb ultrasounds, and 4) recruitment rates for a future randomized trial.
Study of Apixaban for the Prevention of Thrombosis-related Events Following Knee Replacement Surgery...
Deep Vein ThrombosisPulmonary EmbolismThe purpose of this study is to learn if apixaban can prevent blood clots in the leg (deep vein Thrombosis [DVT]) and lung (pulmonary embolism [PE]) that sometimes occur after knee replacement surgery and to learn how apixaban compares to enoxaparin (Lovenox®) for preventing these clots. The safety of apixaban will also be studied.
Study of Apixaban for the Prevention of Thrombosis-related Events in Patients With Acute Medical...
Venous ThrombosisPulmonary EmbolismThe purpose of this study is to learn if apixaban can prevent blood clots in the leg (deep vein thrombosis [DVT]) and lung (pulmonary embolism [PE]) that sometimes occur within patients hospitalized for acute medical illness, and to learn how apixaban compares to enoxaparin (Lovenox®) for preventing these clots. The safety of apixaban will also be studied.
Study Comparing Desirudin With Heparin to Prevent Vein Clots After Heart and Lung Surgery
Deep Venous ThrombosisA blood clot in the veins, also known as deep venous thrombosis (DVT), is one of the most common complications after surgery. This may result in death if a clot breaks off and travel to the lungs; this is referred to as pulmonary embolism (PE). After heart surgery the incidence of DVT ranges from 20-48% and following lung surgery the incidence is 19-26%. In order to decrease the likelihood of this complication, patients receive by injection a blood thinning medicine. Heparin is the usual medicine used for this purpose following heart and lung surgery. Recently there have been reports that other medicines may be more effective than heparin for this purpose. Also there have been reports that some patients develop antibodies to heparin. When this occurs, this may prevent the heparin from being effective and may even promote the formation of blood clots. Antibodies to heparin may be present more often following heart and lung surgery than other types of surgery. There is a new medicine called desirudin (Iprivask), which may be used instead of heparin to prevent blood clots following heart and lung surgery. Desirudin is currently approved by the FDA to prevent blood clots following hip surgery. The purpose of this study is to compare desirudin with heparin for the prevention of vein clots after heart and lung surgery.