Clinical Research Directory

Genetic Testing of CYP2C19 in Prognostic Evaluation of Long-Term Major Adverse Cardiac and Vascular Events

Several studies have shown that the efficacy of clopidogrel for secondary prevention of major adverse cardiovascular events (MACE), including acute coronary syndrome, depends on the polymorphism of the CYP2C19 gene. However, studies with large sample sizes and long-term follow-up are missing. Moreover, the impact of this polymorphism on the risk of major adverse limb events (MALE), particularly in patients with peripheral artery disease of the lower limb, is unexplored. Additionally, the impact of CYP2C19 gene polymorphism on clopidogrel effectiveness in preventing recurrent stroke in diverse populations is unknown since most of the data are from Asian ancestry populations. We hypothesize that patients with CYP2C19 gene loss of function alleles are at high risk of MACE and MALE compared to those without loss of function alleles at long-term follow-up. We propose to assess MACE and MALE in a large cohort of patients with available CYP2C19 genotypes treated at the University of Florida Health to evaluate the impact of CYP2C19 gene polymorphisms on the risk of new or recurrent events at long-term follow-up. Our specific aims are Aim 1) to determine the impact of CYP2C19 gene polymorphisms (loss of function alleles vs. non-loss of function alleles) on the risk of MACE (a composite of all-cause death, non-fatal MI, and non-fatal stroke) at long-term follow-up; Aim 2) to evaluate the impact of CYP2C19 gene polymorphisms (loss of function alleles vs. non-loss of function alleles) on the risk of MALE (a composite of limb amputations, chronic threatening limb ischemia, acute limb ischemia, and limb revascularization) at long-term follow-up; and Aim 3) to evaluate the impact of CYP2C19 gene polymorphisms (loss of function alleles vs. non-loss of function alleles) on the risk of cerebrovascular events (CVE, a composite of any stroke and transient ischemic attack) at long-term follow-up.

Reduced-Dose Apixaban and Rivaroxaban Versus Low-Molecular-Weight Heparin in Patients With Hematologic Malignancies

This study investigates the efficacy and safety of direct oral anticoagulants (DOACs) in comparison with standard low-molecular-weight heparin (LMWH) for the prevention of venous thromboembolism in patients with hematological malignancies. Eligible participants will be randomized to receive reduced-dose apixaban, reduced-dose rivaroxaban, or standard-dose LMWH. The primary objective is to evaluate the incidence of venous thromboembolism during a 6-month follow-up period. Secondary objectives include assessment of bleeding complications, overall survival, and treatment adherence. The results of this study may provide evidence for safer and more convenient thromboprophylaxis strategies in patients with blood cancers.

Efficacy of Prolonged Anticoagulation for Primary Prevention of Venous Thromboembolic Disease in Autoimmune Hemolytic Anemia: a Prospective, Phase II, Randomized, Multicenter Study

Autoimmune hemolytic anemia (AIHA) is a rare autoimmune disease (incidence \<1/100,000 population) responsible for the destruction of red blood cells by the host immune system, notably through the action of autoantibodies. Apart from complications related to anemia, the occurrence of venous thromboembolism (VTE) in this population is frequent, estimated at 20-27%. The risk of VTE is highest during the period of hemolysis, especially during the first 3 months after the diagnosis of AIHA. This risk is 7.5 \[4.7; 12.0\] times greater than in the general population. No clinical predictive factor for VTE was identified and the usual factors (cancer, previous VTE, bed rest \>3 days, surgery, age \>70 years, heart or respiratory failure, myocardial infarction, stroke, obesity, hormone replacement therapy) were not considered. Several biological risk factors have been suggested (depth of anemia, bilirubin level, leukocyte count, antiphospholipid antibodies) but have not been confirmed in other studies. AIHA is therefore a risk factor for VTE in its own right, and the National Diagnostic and Care Protocol (NDCP) recommends the implementation of VTE prevention during acute hemolysis (Grade C). However, the value of this prophylaxis has never been prospectively evaluated and its duration is empirical. In practice, low-molecular-weight heparin (LMWH) is generally used during "flare-ups" of AIHA (diagnosis and relapse) in hospitalized patients, but is rarely continued beyond the hospital phase when VTE also occurs in ambulatory patients. Thus, we hypothesize that prolonged preventive anticoagulation during the 12-week risk period following diagnosis or relapse of AIHA could decrease the incidence of VTE. In orthopedic surgery, this strategy has been proven to decrease VTE from 50% to 10-15%. In certain high-risk medical situations, prolonged prophylaxis with apixaban has been shown to decrease the occurrence of VTE from 10.2% to 4.2% in solid cancers4 and from 4-11% to 2% in myeloma.

CHIPs-VTE Study in Hospitalized Patients to Prevent Hospital-Acquired Venous Thromboembolism

Although pharmacologic and mechanical methods to prevent VTE are safe, effective, cost-effective, and advocated by authoritative guidelines,many studies continue to demonstrate that these preventive methods are significantly underutilized, especially in China.A number of quality improvements (QI) program have been established in several countries or hospitals.However,no exit effective protocol has been demonstrated well enough or adequate to drive breakthrough levels of improvement. A reliable and practical QI that can support hospitals or physicians in China is warranted.To evaluate the multifaceted quality improvement intervention effect in clinical setting, we will conduct a cluster-randomized clinical trial among China PUlmonary Thromboembolism REgistry Study (CURES) group, aiming to test whether it's applicable to real-world practice in China. A multicenter, two-arms, open-label clinical trial has been designed to determine whether the system-wide multifaceted intervention could increase the rate of at-risk participants who received prophylaxis (RP) and decrease the incidence of any hospital-associated VTE in 90 days during and after hospital admission. .Selected hospital will be regarded as a cluster and randomized into interventional or control group.In interventional group, eligible hospitalized patients will receive a variety of the multifaceted quality improvement(QI) interventions since admitted in hospital.In control group, patients will receive no more than common recommended care or an existing policy.The primary outcomes are the proportion of appropriate prophylaxis in hospitalized patients and the incidence of HA-VTE in 90 days after hospital admission.

Cohort for Monitoring Patients With Venous Thromboembolic Disease

Venous thromboembolic disease is a common pathology in the general population (1.5/1000), the prognosis of which depends in particular on the risk of recurrence. This risk depends essentially on whether the thrombotic episode was provoked or not. Thus, patients who present a thromboembolic event without any contributing factor have a high risk of recurrence, which encourages clinicians to continue anticoagulant treatment for a long time. However, anticoagulant treatment is the leading cause of hospitalization for iatrogenic causes and the leading cause of iatrogenic mortality. The benefit-risk balance of treatment must be evaluated regularly, which requires a good knowledge of the risk factors for thrombotic recurrence and the risk factors for hemorrhage.

Risk Factors of Venous Thromboembolism in Women During Hormonal Exposure

Young women have an increased risk of venous thromboembolism (VTE) during hormonale exposure (estrogen-containing pill or pregnancy). In order to detect women at higher risk of VTE during hormonal exposure, thrombophilia testing is often performed in order to adapt contraception methods and/or to increases thromboprophylaxy during pregnancy. However, such practice is probably not accurate nor discriminent. Indeed, there are evidence that the impact of the familial history of VTE might be stronger than that of detectable inherited thrombophilia. The "FIT-H" study is a cross-sectional study comparing the prevalence of previous venous thromboembolism in first-degree relatives of women (propositi) who had a first episode of venous thromboembolism in association with hormonal exposure with the prevalence of previous venous thromboembolism in first-degree relatives of women who did not have venous thromboembolism during a similar hormonal exposure. The primary objective is to determine the association between the presence or the absence of VTE in young women during hormonal exposure and the presence or the absence of a previous episode of VTE in their first-degree relatives. Secondary objective is to determine the impact of associated inherited thrombophilia on the risk of VTE in first-degree relatives.

Best Antithrombotic Therapy in Patients With Acute Venous ThromboEmbolism While Taking Antiplatelets

Venous thromboembolism (VTE) and atherosclerotic cardiovascular disease share common risk factors and frequently coexist in the same patients. Their management requires use of antithrombotic agents: anticoagulant therapy (AC) for secondary prevention of VTE recurrence, antiplatelet (AP) for secondary prevention of major adverse ischemic cardiovascular and cerebrovascular event (MACCE) in patients with atherosclerotic cardiovascular disease (coronary artery disease, atherosclerotic cerebrovascular disease, lower extremity peripheral arterial disease). Side effects of antithrombotic drugs are the 1st cause of emergency admission and hospitalization for an adverse drug reaction (mainly bleeding), and the combination of AC with AP strongly increases this risk.

Venous Thromboembolism in Hematologic Malignancy and Hematopoietic Cell Transplant Patients: a Retrospective Study

Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer, after disease progression. VTE is increasingly recognized as a complication in patients with hematologic malignancies and various studies have reported high rates of VTE. Critically ill patients are at high risk of VTE and should all receive thromboprophylaxis. Given the increasing number of patients with HM (hematologic malignancies) / HCT (Hematopoietic cell transplantation) who develop critical illness, and their often prolonged course, it is imperative to understand the incidence and risk factors for VTE, and to evaluate the efficacy and risks associated with both chemical and mechanical thromboprophylaxis Therefore, the investigators plan to evaluate retrospectively the VTE / PE (pulmonary embolism) incidence in HM /HCT patients at the University of Toronto, and the complications associated with it (including death). In addition, the investigators want to evaluate the use, type (mechanical or pharmacological) and timing of thromboprophylaxis. And lastly, the investigators will determine the incidence of bleeding and of complications associated with chemical and mechanical thromboprophylaxis. The investigators will describe the change in VTE incidence over the last 10 years. The investigators know that patients with COVID-19 infection are at higher risk of thrombosis than non-COVID patients. As such, HM/HCT COVID-19 pts will comprise a subgroup, which will be compared with patients who are not not positive for COVID-19. If these numbers are low, COVID-19 status will be included as a predictive variable in our modelling. The results of this research program will help define indications and safety of VTE prophylaxis; and will inform the development of clinical practice guidelines.

THROmbinography in Pregnant Woman and in Vitro Action of Low Molecular Weight HEparin

Pregnancy is associated with major changes affecting all satges of hemostasis. Certain procoagulant factors are increased, such as factors VII, VIII, IX, X, XII, fibrinogen and Von Willebrand factor. Anticoagulant molecules are also affected by pregnancy, notably the protein C - protein S (PC - PS) system. overall, PC activity is little affected by pregnancy, increasing in the 2nd trimester and decreasing in the 3rd, but remaining within normal values. PS decreases from the first trimester of pregnancy, then progressively with gestational age. Antithrombin is stable during pregnancy. The increased in most coagulation factors, combined with the decrease in concentrations of anticoagulant molecules, creates a state of relative hypercoagulability that protects women from bleeding during homostatic challenge of childbirth, but predisposes them to venous thromboembolic events. The risk of venous thromboembolism (VTE) during pregnancy is increased compared to non-pregnant women of the same age. The post-partum period is also considered a thrombotic risk state for up to 12 weeks after delivery. Data on the incidence of VTE as a function of gestational age are contradictory: depending on the study, incidence may be stable or increase with advancing pregnancy. Low-molecular-weight heparin (LMWH) is the anticoagulant treatment of choice for prophylactic or curative treatment of VTE during pregnancy. Physiological changes during pregnancy may alter the pharmacokinetic properties of LMWH. The increased volume of distribution and higher glomerular filtration rate may result in a reduced anticoagulant effect. On the other hand, the state of hypercoagulability probably counteracts the anticoagulant effect of LMWH. Nevertheless, the need to adjust doses during pregnancy remains controversial, and monitoring of anti-Xa activity is not clearly recommended. The optimal dose of LMWH in pregnant women, for both preventive and curative treatment, remains poorly understood. Initiation of treatment with LMWH therefore requires discussion of the dosage to be administered. Assessment of anticoagulation using more precise tools than those currently available on a routine basis could be useful in this context. Thrombinography enables the amount of thrombin generated in the presence of coagulation activators to be assessed over time. This tool can be used to assess the impact of in vitro addition of different doses of LMWH in pregnant versus non-pregnant women and in the postpartum period. In this pilot study, the investigators propose to evaluate thrombin generation, before and after in vitro addition of LMWH, in pregnant women longitudinally, during the 3 trimesters of pregnancy, postpartum and post-pregnancy.

Alerting Providers at Patient Hospital Discharge to Consider Prescribing Rivaroxaban to Reduce Venous Thromboembolism

A new algorithm derived from only patient age and components of the complete blood count and basic metabolic panel can identify patients discharged from the hospital who may benefit from a blood thinner (called rivaroxaban) to decrease their risk of blood clots, and for whom the risk of bleeding is minimal. The purpose of this study is to evaluate the use of a pop-up alert, which will be seen by clinicians when a discharging patient has been identified as being someone for whom the risk of blood clots is high, but for whom bleeding risk is estimated to be low. The pop-up alert will be enabled in a sequential fashion for each group of hospitals in 1 month blocks. We will look to see if the pop-up alert changes the number of patients who receive rivaroxaban. We will also measure the outcomes of blood clots and bleeding among all discharging patients.