Study to Develop a Reliable Nomogram That Incorporates Clinical and Genetic Information

Summary

In this research study, the investigators are trying to find a better way to set the dose of a common blood-thinning medication.

Patients with blood clots or a risk of blood clots (or stroke) sometimes have to take an approved medication called warfarin. Warfarin is a commonly prescribed, approved blood thinning medicine taken by mouth. There is a certain level of warfarin that is best for each patient at a particular time. It is hard for a doctor to choose and maintain the right dose of warfarin for each patient. Too much or too little warfarin in the blood can cause serious health problems.

A "nomogram" is a tool that helps doctors decide on the right dose of warfarin. The usual way for finding the right dose of warfarin is for doctors to take an educated guess and use a "trial and error" approach. Patients have frequent blood tests to help doctors keep track of how well the dose level is working.

Up until now, if a patient had good blood test results over half of the time, that was as well as doctors could do. The purpose of this study is to see whether the investigators can create a reliable new warfarin nomogram that will allow them to dose a patient correctly more often, perhaps about 3 times out of 4. The nomogram the investigators are studying uses information about a patient's health and genes to decide on the best dose of warfarin.

The investigators don't yet have a reliable, safe way to choose the correct dose. In this study, the investigators will use a genetic blood test to try to find a better way. Genes are the parts of each living cell that allow characteristics to be passed on from parents to children. The investigators know that people with certain genes seem to respond to warfarin in a certain way. From a blood sample, the investigators can look at patients' genes and try to predict the response to the blood-thinning medication.

There will be about 500 subjects taking part in this study. They will come from participating Partners' Hospitals, including Brigham and Women's Hospital, Massachusetts General Hospital, Faulkner Hospital, Newton-Wellesley Hospital, Spaulding Rehabilitation Hospital, and North Shore Medical Center. The U.S. Food and Drug Administration (FDA) has approved warfarin for use as a blood thinner.

Conditions

• Pulmonary Embolism
• Deep Vein Thrombosis
• Atrial Fibrillation

Interventions

DRUG

Warfarin

2 mg tablets take as directed by study staff (based on INR)

Sponsors & Collaborators

• Massachusetts General Hospital

  collaborator OTHER

• Newton-Wellesley Hospital

  collaborator OTHER

• Spaulding Rehabilitation Hospital

  collaborator OTHER

• Brigham and Women's Hospital

  lead OTHER

Principal Investigators

• Mark A Creager, MD · Brigham and Women's Hospital

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2007-01-31

Primary Completion

2011-06-30

Completion

2011-06-30

Countries

• United States

Study Locations