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Trial record 75 of 156 for:    warfarin AND Vitamin K

Warfarin and Coronary Calcification Project (WACC)

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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:
Information provided by (Responsible Party):
Todd C. Villines, Walter Reed Army Medical Center

Study Type Observational
Study Design Observational Model: Cohort;   Time Perspective: Prospective
Condition Coronary Calcification
Enrollment 70
Recruitment Details Recruitment is complete. All patients were recruited from within the Walter Reed Anticoagulation Clinic, as specified in the protocol.
Pre-assignment Details  
Arm/Group Title Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Hide Arm/Group Description Warfarin use for less than 6 months Warfarin use for 6 to 24 months in duration Warfarin use >24 months
Period Title: Overall Study
Started 31 11 28
Completed 31 11 28
Not Completed 0 0 0
Arm/Group Title Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic Total
Hide Arm/Group Description Warfarin use for less than 6 months Warfarin use for 6 to 24 months in duration Warfarin use >24 months Total of all reporting groups
Overall Number of Baseline Participants 31 11 28 70
Hide Baseline Analysis Population Description
[Not Specified]
Age, Categorical  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 31 participants 11 participants 28 participants 70 participants
<=18 years
0
   0.0%
0
   0.0%
0
   0.0%
0
   0.0%
Between 18 and 65 years
21
  67.7%
4
  36.4%
9
  32.1%
34
  48.6%
>=65 years
10
  32.3%
7
  63.6%
19
  67.9%
36
  51.4%
Age Continuous  
Mean (Standard Deviation)
Unit of measure:  Years
Number Analyzed 31 participants 11 participants 28 participants 70 participants
64  (13) 68  (11) 73  (12) 68  (13)
Sex: Female, Male  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 31 participants 11 participants 28 participants 70 participants
Female
10
  32.3%
5
  45.5%
9
  32.1%
24
  34.3%
Male
21
  67.7%
6
  54.5%
19
  67.9%
46
  65.7%
Region of Enrollment  
Measure Type: Number
Unit of measure:  Participants
United States Number Analyzed 31 participants 11 participants 28 participants 70 participants
31 11 28 70
1.Primary Outcome
Title 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
Hide Description 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.
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.
Hide Outcome Measure Data
Hide Analysis Population Description
After interim analysis following n=70 showed no effect, further enrollment was halted.
Arm/Group Title Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Hide Arm/Group Description:
Warfarin use for less than 6 months
Warfarin use for 6 to 24 months in duration
Warfarin use >24 months
Overall Number of Participants Analyzed 31 11 28
Mean (Standard Deviation)
Unit of Measure: Agatston Score
175  (285) 289  (382) 426  (789)
2.Secondary Outcome
Title International Normalized Ratio
Hide Description 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.
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.
Hide Outcome Measure Data
Hide Analysis Population Description
[Not Specified]
Arm/Group Title Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Hide Arm/Group Description:
Warfarin use for less than 6 months
Warfarin use for 6 to 24 months in duration
Warfarin use >24 months
Overall Number of Participants Analyzed 31 11 28
Mean (Standard Deviation)
Unit of Measure: ratio
1.8  (0.9) 2.4  (0.4) 2.5  (0.4)
Time Frame 1 month (until calcium scan completed).
Adverse Event Reporting Description [Not Specified]
 
Arm/Group Title Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Hide Arm/Group Description Warfarin use for less than 6 months Warfarin use for 6 to 24 months in duration Warfarin use >24 months
All-Cause Mortality
Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Affected / at Risk (%) Affected / at Risk (%) Affected / at Risk (%)
Total   --/--   --/--   --/-- 
Show Serious Adverse Events Hide Serious Adverse Events
Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Affected / at Risk (%) Affected / at Risk (%) Affected / at Risk (%)
Total   0/31 (0.00%)   0/11 (0.00%)   0/28 (0.00%) 
Show Other (Not Including Serious) Adverse Events Hide Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events 1%
Warfarin Use Short Duration 2 - Warfarin Use Intermediate 3 - Warfarin Use Chronic
Affected / at Risk (%) Affected / at Risk (%) Affected / at Risk (%)
Total   0/31 (0.00%)   0/11 (0.00%)   0/28 (0.00%) 
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.
Certain Agreements
All Principal Investigators ARE employed by the organization sponsoring the study.
Results Point of Contact
Layout table for Results Point of Contact information
Name/Title: Todd C. Villines, MD
Organization: Walter Reed Army Medical Center, Cardiology Service
Phone: 301-295-7839
EMail: todd.villines@us.army.mil
Layout table for additonal information
Responsible Party: Todd C. Villines, Walter Reed Army Medical Center
ClinicalTrials.gov Identifier: NCT00868712     History of Changes
Other Study ID Numbers: WU# 04-12020
First Submitted: March 24, 2009
First Posted: March 25, 2009
Results First Submitted: February 2, 2010
Results First Posted: August 24, 2012
Last Update Posted: August 24, 2012