Warfarin and Coronary Calcification Project

Study Overview
=================
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.

Official Title
-----------------
Warfarin and Coronary Calcification Project

Conditions
-----------------
Coronary Calcification

Participation Criteria
=================
Eligibility 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

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1<br>Warfarin use < 6 months | |
| 2<br>Warfarin use 6-24 months | |
| 3<br>Warfarin use >24 months | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| International Normalized Ratio | 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. | 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. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
coronary calcification, vitamin K dependent proteins, warfarin