Fiix-prothrombin Time for Monitoring Warfarin

The recruitment status of this study is unknown because the information has not been verified recently.
Verified March 2012 by Landspitali University Hospital.
Recruitment status was  Recruiting
Sponsor:
Collaborator:
University of Rochester
Information provided by (Responsible Party):
Pall T. Onundarson, M.D., Landspitali University Hospital
ClinicalTrials.gov Identifier:
NCT01565239
First received: March 22, 2012
Last updated: March 27, 2012
Last verified: March 2012
  Purpose

Experiments suggest that during treatment with vitamin K antagonists (VKA) the activity of coagulation factors (F) II and X better reflect anticoagulation than does FVII. Based on this a new prothrombin time based monitoring test (Fiix-PT) has been invented which is only sensitive to FII and FX. The Fiix-PT can be converted to INR ("Fiix-INR").

The investigators hypothesize that the Fiix-PT may reflect anticoagulation and the antithrombotic effect of VKA as accurately or better than the current PT based tests do (INR based on PT or P&P). The protocol describes a prospective randomized double-blind trial that will be conducted at the Landspitali Anticoagulation Management Center (AMC).

The objective of the protocol is to evaluate the efficacy and safety of Fiix-INR as a monitoring test compared to the current PT based assays (INR) used to monitor patients treated with VKA to prevent thromboembolism. The investigators will randomize 1200 clients of the AMC into two identically sized monitoring groups, Fiix-INR (test group) and INR (control group).

The clinical endpoints to be studied include efficacy (arterial and venous thromboembolic event rate) and safety (bleeding events). Additionally, surrogate convenience endpoints will be studied such as test frequency and time within target range.


Condition Intervention Phase
Thromboembolism
Arterial
Venous
Device: Fiix prothrombin time
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Clinical Outcome During Warfarin Anticoagulation Monitored With "Fiix-INR" Compared to Standard Monitoring With INR.A Prospective Randomized Double-blinded Trial.

Resource links provided by NLM:


Further study details as provided by Landspitali University Hospital:

Primary Outcome Measures:
  • Thromboembolic events [ Time Frame: 1200 patients years of observation time, 18 months on average for each participant ] [ Designated as safety issue: No ]

    7.2.2 Primary Efficacy criteria

    The following definitions will be applied by the IAC to confirm a suspected episode of symptomatic recurrent TE:

    1. Venous thromboembolism (VTE).

      1. All objectively diagnosed VTE (by imaging technology or autopsy) will be included
      2. Superficial thromboses will not be included
    2. Arterial thromboembolism (ATE)

      1. All objectively confirmed ATE (by imaging techniques, surgically, autopsy, EKG etc) will be included
      2. Transient ischemic attacks of any kind (TIA´s, RIND´s) will be included

  • Major hemorrhage [ Time Frame: 1200 patient years of observation, 18 months on average for each study participant ] [ Designated as safety issue: Yes ]

    7.2.3 Safety outcome criteria The principal safety outcome is clinically relevant bleeding (i.e., major bleeding and clinically relevant non-major bleeding).

    Additional safety outcomes include all deaths and other vascular events. 7.2.3.1 Bleeding definitions All suspected bleedings will be reported and will be classified by the IAC as major, clinically relevant non-major, trivial, or no bleeding.

    Major bleeding see ISTH criteria JTH 2005;3:692-4



Secondary Outcome Measures:
  • Monitoring test frequency and time spent within target range [ Time Frame: 1200 patients years of observation ] [ Designated as safety issue: No ]

    We will compare the following in the test group and the control group:

    i. Total number of tests per treatment year ii. Dose adjustment frequency (interval or number of dose adjustments during observation period) iii. Percent tests within treatment range over observation period iv. Percent time within target range (TTR) over observation period



Estimated Enrollment: 1200
Study Start Date: March 2012
Estimated Study Completion Date: January 2014
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Fiix PT (Fiix-INR) monitoring and dosing of warfarin
The modified prothrombin time, sensitive only to factor II and X activity, will be used to monitor and dose warfarin.
Device: Fiix prothrombin time
The Fiix prothrombin time (or Stuart-prothrombin time) is a new modification of the currently used prothrombin times. The Fiix PT as opposed to PT is sensitive to the activity of coagulation factors II and X only whereas the PT is sensitive to factors I, II, V, VII and X.
Active Comparator: PT (INR) monitoring and dosing of warfarin
The prothrombin time, sensitive to factors II, VII and X activity, will be used to monitor and dose warfarin.
Device: Fiix prothrombin time
The Fiix prothrombin time (or Stuart-prothrombin time) is a new modification of the currently used prothrombin times. The Fiix PT as opposed to PT is sensitive to the activity of coagulation factors II and X only whereas the PT is sensitive to factors I, II, V, VII and X.

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • age 18 or over,
  • INR treatment goal of 2-3,
  • ability to sign informed consent

Exclusion Criteria:

  • nursing home patients
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01565239

Contacts
Contact: Pall T Onundarson, M.D. +354 543 1000 ext 5010 pallt@landspitali.is
Contact: Brynja R Gudmundsdottir, M.Sc. +354 543 2383 brynjarg@landspitali.is

Locations
Iceland
Landspitali University Hospital Recruiting
Reykjavik, N.a., Iceland, 101
Principal Investigator: Pall T. Onundarson, M.D.         
Sponsors and Collaborators
Landspitali University Hospital
University of Rochester
Investigators
Principal Investigator: Pall T. Onundarson, M.D. Landspitali and University of Iceland, Faculty of Medicine
  More Information

No publications provided

Responsible Party: Pall T. Onundarson, M.D., Professor of Hematology, Head of Hematology Laboratory and Coagulation Disorders, Landspitali University Hospital
ClinicalTrials.gov Identifier: NCT01565239     History of Changes
Other Study ID Numbers: Landspitali-1
Study First Received: March 22, 2012
Last Updated: March 27, 2012
Health Authority: Iceland: Ministry of Health and Social Security

Keywords provided by Landspitali University Hospital:
Warfarin
Monitoring
prothrombin time
Fiix prothrombin time
international normalized ratio (INR)
new test

Additional relevant MeSH terms:
Thromboembolism
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Thrombosis
Thrombin
Warfarin
Hemostatics
Coagulants
Hematologic Agents
Therapeutic Uses
Pharmacologic Actions
Anticoagulants

ClinicalTrials.gov processed this record on July 22, 2014