Early Identification of Warfarin Maintenance Dosage

Atrial Fibrillation Clinical Trial

Official title:

Early Identification of Warfarin Maintenance Dose in Patients With Atrial Fibrillation: a Randomized Trial Evaluating a New Genotype-based Versus Usual Care Initiation of Treatment

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01178034
• Other study ID #: 1643P
• Status: Completed
• Phase: Phase 3
• First received: August 6, 2010
• Last updated: October 21, 2012
• Start date: October 2009
• Est. completion date: October 2012

Study information

• Verified date: October 2012
• Source: University of Padova
• Contact: n/a
• Is FDA regulated: No
• Health authority: Italy: The Italian Medicines Agency
• Study type: Interventional

Clinical Trial Summary

Initiation of warfarin therapy is problematic. The investigators goal was to evaluate if a new demographic/pharmacogenetic algorithm is better than a usual algorithm based on INR value at day five after four days of 5 mg/day warfarin. To this end patients with atrial fibrillation starting warfarin are randomized in two arms.

Description:

The objective of this randomized study is to evaluate the accuracy of a new demographic/pharmacogenetic as compared to usual warfarin dosing algorithm in predicting warfarin maintenance dose. In patients with atrial fibrillation starting anticoagulation, the loading dose of warfarin in the tested group is calculated on the basis of VKORC1 genotype and patient's body weight.The second day warfarin maintenance dose is calculated on the basis of surface area and CYP2C9, CYP4F2 e VKORC1 genotype. In the usual care group the maintenance dose at day 5 is calculated on the basis of a published algorithm (Pengo V, Am J Cardiol 2001). INR is checked on day 0, 5, 7, 9, 12, 15 and 19. Primary end-point of the trial is the number of INR outside the therapeutic range of 2.0 to 3.0. Secondary end-points are the number of changes in dose prescription, the difference between predicted and actual warfarin maintenance dose and thrombotic and bleeding events.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 180
• Est. completion date: October 2012
• Est. primary completion date: October 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Age >18 years

• Indication to warfarin with INR between 2.0 and 3.0

Exclusion Criteria:

• Pregnancy

• Drug interactions

• Basal INR > 1.2

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Atrial Fibrillation

Intervention

Genetic:
• Calculate warfarin dose using demographic/genetic algorithm
Age, body weight and genetic to calculate warfarin dosage

Locations

Country	Name	City	State
Italy	Thrombosis Centre	Padova

Sponsors (1)

Lead Sponsor	Collaborator
University of Padova

Country where clinical trial is conducted

Italy, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	International Normalized Ratio (INR)	Number of INR outside the therapeutic range (INR 2.0-3.0)	Day 0, 5, 7, 9, 12, 15, 19.	Yes
Secondary	Number of changes in warfarin dosage		Day 0-19	Yes
Secondary	Difference between predicted and actual warfarin maintenance dose		Day 19	Yes
Secondary	Thromboembolic and Bleeding complications		Day 0-30	Yes