Pharmacogenomics of Warfarin in Hispanics and Latinos

June 25, 2024 updated by: Jason H Karnes, University of Arizona

Warfarin is a commonly used blood thinner to treat and prevent blood clots. It is important to take the right dose of warfarin because too much can increase the risk of bleeding and too little can increase the risk of blood clots. This is why patients are closely monitored especially when they begin warfarin therapy. When clinicians prescribe warfarin, they have to consider different factors such as patient's age, body size, diet, and other medications that can interact with warfarin.

Certain genes have also been found to affect warfarin dose. Individuals have variations in these genes, which can help explain why some patients need higher dose and others require less. These factors have been used to better predict a patient's warfarin dose requirement. However, these predictions were created based on Caucasian populations and they may not be accurate in predicting a safe warfarin dose if a patient is not Caucasian. This study aims to identify new genetic variation that affects warfarin dosing in Hispanic and Latino populations and try to better predict a Hispanic or Latino patient's warfarin dose requirement.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

If the patient is willing to hear about the study, during routine clinical care, one of the patient's providers will approach patients meeting the study criteria about participation in the study. Study personnel will not approach potential participants unless permission is given to the patient's provider. If the patient would like to participate in the study, study personnel will discuss details of the study in person during the patient's routine clinical care visit. There will also be a flyers available for posting and for distribution to potential participants.

Participants consenting to the study will be asked to provide a cheek swab or mouthwash sample to provide buccal cells for DNA extraction. If the patient is receiving a blood draw during their regular clinical appointment, participants will be asked for a blood sample of 15 milliliters. Genomic DNA will be isolated for genotyping and patient plasma samples will also be stored.

Linear regression will be used to test association of SNPs with therapeutic warfarin dose using the algorithms derived by the International Warfarin Pharmacogenomics Consortium. The primary phenotype (weekly stable warfarin dose) will be transformed by square root. SNPs and other variables associated with warfarin dose will be assessed in univariate analyses and entered into stepwise linear regression to determine the adjusted association with dose requirements using R2. Quality control procedures will include deviation from Hardy-Weinberg Equilibrium, and SNP and sample exclusions based on call rates. Ancestry-informative marker (AIM) analysis will be performed to estimate ancestry in each individual.

Study Type

Observational

Enrollment (Estimated)

400

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Arizona
      • Tucson, Arizona, United States, 85721
        • Recruiting
        • Banner University Medical Center - Tucson
        • Contact:

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

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population will be Hispanic and Latino patients on stable doses of warfarin therapy.

Description

Inclusion Criteria:

  • At least 18 years of age
  • Ability to give informed consent
  • Therapeutic INR for at least 2 consecutive clinic visits
  • Self-identifies as Hispanic or Latino

Exclusion Criteria:

  • Less than 18 years old
  • Unable to give informed consent
  • Severe hepatic impairment

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Stable warfarin dose
Time Frame: At time of enrollment
Dose of warfarin required to maintain stable INR for at least 2 consecutive clinic visits.
At time of enrollment

Collaborators and Investigators

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

Sponsor

University of Arizona

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)

September 1, 2016

Primary Completion (Estimated)

September 1, 2026

Study Completion (Estimated)

September 1, 2026

Study Registration Dates

First Submitted

November 21, 2016

First Submitted That Met QC Criteria

November 21, 2016

First Posted (Estimated)

November 23, 2016

Study Record Updates

Last Update Posted (Actual)

June 27, 2024

Last Update Submitted That Met QC Criteria

June 25, 2024

Last Verified

June 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1608762767

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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