Assessment of The Effect of Apixaban in AF

February 6, 2019 updated by: Prof Diana Gorog, East and North Hertfordshire NHS Trust

Assessing The Effect of Apixaban on Endogenous Fibrinolysis in Patients With Non-Valvular Atrial Fibrillation

This study will assess the effect of apixaban on thrombotic status in patients with atrial fibrillation.In addition it will compare apixaban to aspirin and warfarin on their effect on endogenous fibrinolysis.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Patients with an irregular heart rhythm called atrial fibrillation (AF) have an increased risk of forming blood clots inside the heart, that can then fragment and break off, travelling through the circulation to the brain, where it can cause blockage of the small blood vessels resulting in a stroke. Most patients with AF are prescribed blood thinning medications in an attempt to prevent such clot formation. The body has the ability through enzymes circulating in blood, to dissolve a clot once formed, such that even if a clot is formed, it is rapidly dissolved and no lasting damage is sustained. This is known as endogenous fibrinolysis. If this defence system is faulty or suboptimal, there is an increased risk of clot formation, resulting in stroke or heart attack. Currently, there are no available tablets to favourably modify this defence system of endogenous fibrinolysis. The investigators will assess how this defence system functions in patients with AF who are on different blood thinners. Then the investigators will also assess a group of patients before and during treatment with a relatively new blood thinner called apixaban, to assess the effect of this on the stickiness of blood and the ability of the blood to dissolve clots (endogenous fibrinolysis). All the blood thinners will be prescribed for clinical indications, not as part of the research. The research aspect of the study is that we will perform a blood test to assess endogenous fibrinolysis.

Understanding the effect of apixaban on endogenous fibrinolysis raises the possibility that apixaban, rather than other blood thinners, may be of particular use in patients with impaired fibrinolysis who are at particularly high risk of clots due to inefficient endogenous fibrinolysis.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
240

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
      • Stevenage, United Kingdom, SG14AB
        • Hertfordshire Cardiology Centre, East and North Hertfordshire NHS Trust

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Patients with non-valvular atrial fibrillation. Participants will be recruited via inpatient and outpatient clinical areas.

Description

Inclusion Criteria:

  1. Age >18 years
  2. Diagnosis of NVAF (nonvalvular atrial fibrillation)
  3. Requiring anticoagulation or antiplatelet therapy for thromboprophylaxis of stroke and systemic embolism
  4. No contra-indications to apixaban (except for those patients taking part in baseline cross-sectional study where this inclusion criterion does not apply)
  5. Patient does not meet any of the exclusion criteria below

Exclusion Criteria:

  1. Patient unwilling or unable to give informed consent
  2. Patient already taking antiplatelet or anticoagulant therapy (except for those patients taking part in baseline cross-sectional study, where this exclusion criterion does not apply)
  3. Patient who, in the opinion of the investigator, has significant hepatic or renal impairment likely to cause a bleeding diathesis
  4. Patient needing systemic high dose steroids or immunosuppression that may impact on platelet function
  5. Patient with ongoing active alcohol or substance abuse or demonstrates signs or clinical features of active substance abuse
  6. Patient with any major bleeding diathesis or blood dyscrasia at baseline (platelets<70 x 109/l, Hb<80 g/l, INR >1.4 (international normalized ratio), APTT (activated partial thromboplastin time ) > x 2UNL (upper normal limit) , leucocyte count< 3.5x 109/l, neutrophil count<1x 109/l).
  7. Patient currently involved in another investigational trial of a medicine or medical device

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Atrial Fibrillation newly diagnosed, starting apixaban
Patients will undergo the global thrombosis test (GTT), thromboelastography (TEG) and thrombin generation assays before and after stabilisation(4 weeks) of their anticoagulation. This will allow to compare the effect of apixaban on endogenous fibrinolysis before and after treatment.
Other: Thrombin generation assays, Thromboelastography (TEG), and Global Thrombosis Test (GTT)
Global Thrombosis Test (GTT): assesses formation of the blood clot and how easily can this be broken down once formed) Thromboelastography (TEG) :assesses the properties of a blood clot and how easily can be broken down Thrombin generation assays: assesses the formation of a blood clot and the potential of thrombolysis via the introduction of different buffer solutions
Atrial fibrillation on stable warfarin treatment
Patients will undergo the global thrombosis test (GTT), thromboelastography (TEG) and thrombin generation assays on stable anticoagulation treatment. This will allow to compare the effect of apixaban against warfarin on endogenous fibrinolysis on stable treatment.
Other: Thrombin generation assays, Thromboelastography (TEG), and Global Thrombosis Test (GTT)
Global Thrombosis Test (GTT): assesses formation of the blood clot and how easily can this be broken down once formed) Thromboelastography (TEG) :assesses the properties of a blood clot and how easily can be broken down Thrombin generation assays: assesses the formation of a blood clot and the potential of thrombolysis via the introduction of different buffer solutions
Atrial Fibrillation on stable aspirin treatment
Patients will undergo the global thrombosis test (GTT), thromboelastography (TEG) and thrombin generation assays on stable anticoagulation treatment. This will allow to compare the effect of apixaban against aspirin on endogenous fibrinolysis on stable treatment.
Other: Thrombin generation assays, Thromboelastography (TEG), and Global Thrombosis Test (GTT)
Global Thrombosis Test (GTT): assesses formation of the blood clot and how easily can this be broken down once formed) Thromboelastography (TEG) :assesses the properties of a blood clot and how easily can be broken down Thrombin generation assays: assesses the formation of a blood clot and the potential of thrombolysis via the introduction of different buffer solutions

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Assessing the effect of apixaban on endogenous fibrinolysis in patients wth atrial fibrillation
Time Frame: Change of endogenous fibrinolysis from baseline at 4 weeks
Measuring endogenous fibrinolysis before and after apixaban
Change of endogenous fibrinolysis from baseline at 4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Comparing the effect of apixaban to warfarin and aspirin on endogenous fibrinolysis in patients with atrial fibrillation
Time Frame: 12 months
Compare the effect on endogenous fibrinolysis as measured by occlusion time and lysis time (seconds) of stable apixaban, warfarin and aspirin treatment in patients with atrial fibrillation with the GTT,TEG,thrombin generation assays
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
East and North Hertfordshire NHS Trust

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Hertfordshire

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 2, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 2, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 13, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 23, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 27, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 7, 2019

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 6, 2019

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • No 1.1 Apr 2017
  • CV185-622 (Other Grant/Funding Number: BMS/Pfizer European Thrombosis Investigator Initiated Research Program)
  • RD2017-03 (Other Identifier: East and North Hertfordshire NHS Trust)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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