Warfarin and Coronary Calcification Project (WACC)

• ClinicalTrials.gov Identifier: NCT00868712
• Recruitment Status: Completed
• First Posted: March 25, 2009
• Results First Posted: August 24, 2012
• Last Update Posted: August 24, 2012
• Sponsor: Walter Reed Army Medical Center
• Information provided by (Responsible Party): Todd C. Villines, Walter Reed Army Medical Center

Study Description

Brief Summary:

The purpose of the study is to assess whether the use of warfarin, a commonly used anticoagulation drug, is associated with increased amounts of coronary artery calcification. Studies in animals and preliminary but small retrospective studies in humans have suggested a possible link to increased tissue calcification with use of this drug. The researchers will investigate this by assessing the amount of calcification seen in the coronary arteries using a specialized computed tomography (CT) scan (electron-beam CT) and assessing to see if the amount is influenced by the amount of time a patient has been taking warfarin. The researchers will exclude patients with known coronary artery disease, chronic kidney disease or hyperparathyroidism.

Condition or disease
Coronary Calcification

Study Design

• Study Type: Observational
• Actual Enrollment: 70 participants
• Observational Model: Cohort
• Time Perspective: Prospective
• Official Title: Warfarin and Coronary Calcification Project
• Study Start Date: May 2004
• Actual Primary Completion Date: January 2010
• Actual Study Completion Date: January 2010

Groups and Cohorts

Group/Cohort
1; Warfarin use < 6 months
2; Warfarin use 6-24 months
3; Warfarin use >24 months

Outcome Measures

Primary Outcome Measures :

1. Coronary Calcification (Presence and Degree as Measured by Agatston Score) Attributed to Duration of Warfarin Use in Months After Controlling for Standard Cardiovascular Risk Factors to Include the Framingham Risk Score [ Time Frame: EBCT scan is done at time of enrollment of patient into 1 of 3 groups based on warfarin use duration: <6 months; 6-24 months; >24 mos. ]
   The Agatston score is calculated using a non-contrast computed tomography (CT) scan to measure for the presence and severity of coronary artery disease through identification of calcification in the coronary arteries. Scores can range from 0 to several thousands. The measure is without units. Score categories are as follows: 0 = no coronary disease; 1-100 = low amount of coronary artery disease; 101-400 = moderately elevated score / moderate coronary artery disease; 401-1000 = severely elevated score; >1000 very severely elevated score. Higher Agatston scores corelate with more coronary artery disease and predict a higher risk of coronary heart disease events and mortality.

Secondary Outcome Measures :

1. International Normalized Ratio [ Time Frame: EBCT scan is done at time of enrollment of patient into 1 of 3 groups based on warfarin use duration: <6 months; 6-24 months; >24 mos. ]
   The International Normalized Ratio (INR) is a standardized lab value that measures the intensity of anticogulation using warfarin. It is used to monitor patients taking warfarin.

Eligibility Criteria

• Ages Eligible for Study: 18 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No
• Sampling Method: Non-Probability Sample

Study Population

Patients without known coronary heart disease, disorders of calcium metabolism or chronic kidney disease aged > 18 years who are referred to take or currently taking warfarin and are followed in the Anticoagulation Management Clinic at Walter Reed Army Medical Center (WRAMC).

Criteria

Inclusion Criteria:

• Age 18 years of age or older
• Patients referred to begin or already treated with warfarin anticoagulation therapy.

Exclusion Criteria:

• Known prior myocardial infarction or coronary heart disease
• History of advanced chronic kidney disease manifested by serum creatinine>2 or calculated glomerular filtration rate (GFR)<30
• History of hyperparathyroidism
• Current hypercalcemia
• Current hyperphosphatemia
• Uncertain duration of warfarin therapy
• Lack of records documenting international normalized ratio (INR) during therapy

Contacts and Locations

Locations

United States, District of Columbia

Walter Reed Army Medical Center

Washington, District of Columbia, United States, 20307

Sponsors and Collaborators

Walter Reed Army Medical Center

More Information

Additional Information:

Publication abstract 

Publications of Results:

Villines TC, O'Malley PG, Feuerstein IM, Thomas S, Taylor AJ. Does prolonged warfarin exposure potentiate coronary calcification in humans? Results of the warfarin and coronary calcification study. Calcif Tissue Int. 2009 Dec;85(6):494-500. doi: 10.1007/s00223-009-9300-4. Epub 2009 Oct 22.

• Responsible Party: Todd C. Villines, Director, Cardiovascular Research, Walter Reed Army Medical Center
• ClinicalTrials.gov Identifier: NCT00868712 History of Changes
• Other Study ID Numbers: WU# 04-12020
• First Posted: March 25, 2009
• Results First Posted: August 24, 2012
• Last Update Posted: August 24, 2012
• Last Verified: August 2012

Keywords provided by Todd C. Villines, Walter Reed Army Medical Center:

coronary calcification; vitamin K dependent proteins; warfarin

Additional relevant MeSH terms:

Calcinosis; Calcium Metabolism Disorders; Metabolic Diseases; Warfarin; Anticoagulants