Warfarin and Coronary Calcification Project

NCT00868712 | Completed Results DMC

• 1 other identifier: WU# 04-12020
• Study Type: observational
• Target: 70
• Locations: 1 country
• Sites: 1

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.

Conditions

Coronary Calcification

Keywords

coronary calcification; vitamin K dependent proteins; warfarin

Outcome Measures

Primary Outcomes (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

  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.

  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.

Secondary Outcomes (1)

• International Normalized Ratio

  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.

Study Arms (3)

1

Warfarin use \< 6 months

2

Warfarin use 6-24 months

3

Warfarin use \>24 months

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• 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).

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• Walter Reed Army Medical Center: lead

Study Sites (1)

Walter Reed Army Medical Center

Washington D.C., District of Columbia, 20307, United States

Location

Related Publications (1)

• 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.

  PMID: 19847375 RESULT

Related Links

• Publication abstract

Limitations and Caveats

Cross-sectional nature, small sample size. Initially powered for sample size of 100 subjects, our trial was stopped early after an interim analysis at 70 subjects demonstrated no trend for effect of warfarin after adjusting for standard risk factors.

Results Point of Contact

• Title: Todd C. Villines, MD
• Organization: Walter Reed Army Medical Center, Cardiology Service

todd.villines@us.army.mil

301-295-7839

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: FED
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director, Cardiovascular Research

Study Record Dates

• First Submitted: March 24, 2009
• First Posted: March 25, 2009
• Study Start: May 1, 2004
• Primary Completion: January 1, 2010
• Study Completion: January 1, 2010
• Last Updated: August 24, 2012
• Results First Posted: August 24, 2012

Record last verified: 2012-08

Locations

US (1)