Monitoring Anticoagulant Therapy in Antiphospholipid Syndrome

Monitoring Anticoagulant Therapy With Vitamin-K Antagonists in Patients With Antiphospholipid Syndrome

To Assess the Influence of Antiphospholipid Antibodies on INR Test Results in Patients with the Antiphospholipid Syndrome Anticoagulated with Vitamin-K Antagonists.

Study Overview

• Status: Completed
• Conditions: Antiphospholipid Syndrome

Detailed Description

Patients with an antiphospholipid syndrome receiving Vitamin-K antagonists for secondary prevention after a first thrombotic complication are known to be at higher risk of recurrent thrombotic events despite INR values in the therapeutic range. It ist also known that antiphospholipid antibodies can interfere with phospholipid-dependent tests (e.g. prothrombin time and INR).

The primary objective of this study is to determine the prevalence of interfering antiphospholipid antibodies. The intensity of anticoagulant therapy was assessed by measuring the INR using different thromboplastins and the CoaguChek system for INR self-assessment. Test results were compared to measurements of the phospholipid-independent chromogenic factor X.

The second objective of this study is to evaluate the incidence of recurrent thrombotic events during 1-year follow-up.

• Study Type: Observational
• Enrollment (Anticipated): 150

Contacts and Locations

Study Locations

• Germany
  • Hessen
    • Frankfurt/Main, Hessen, Germany, D-60590
      • Goethe University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with antiphospholipid syndrome requiring long-term treatment with vitamin-K antagonists (N=40) Pateints without antiphospholipid antibodies treated with vitamin-K antagonists (N=100)

Description

Inclusion Criteria:

• age 18-90 years

Exclusion Criteria:

• none

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
APS patients; Patients with antiphospholipid syndrome requiring long-term anticoagulant therapy with vitamin-K antagonists
Controls; Patients without antiphospholipid antibodies requiring anticoagulant therapy with vitamin-K antagonists

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Difference between INR and CFX correlate >20%	0, 1, 2, 3, 6 and 12 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Arterial or venous thrombosis	Any arterial of venous thrombosis occurring under anticoagulant treatment with vitamin-K antagonists during 1-year follow-up	12 months

Collaborators and Investigators

• Sponsor: Johann Wolfgang Goethe University Hospital
• Investigators: Principal Investigator: Birgit Linnemann, MD, Goethe University Hospital, Division of Vascular Medicine

Publications and helpful links

Helpful Links

• Click here for more information about this study: Monitoring Anticoagulant Therapy in Antiphospholipid Syndrome

Study record dates

Study Major Dates

• Study Start: July 1, 2011
• Primary Completion (Actual): June 1, 2014
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: August 6, 2012
• First Submitted That Met QC Criteria: August 6, 2012
• First Posted (Estimate): August 8, 2012

Study Record Updates

• Last Update Posted (Estimate): April 15, 2015
• Last Update Submitted That Met QC Criteria: April 14, 2015
• Last Verified: April 1, 2015

More Information

Terms related to this study

• Keywords: Antiphospholipid syndrome; Antiphospholipid antibodies; International normalized ratio; Vitamin-K antagonists; Chromogenic factor X
• Additional Relevant MeSH Terms: Pathologic Processes; Immune System Diseases; Autoimmune Diseases; Disease; Syndrome; Antiphospholipid Syndrome
• Other Study ID Numbers: EV 77/11