Warfarin use and prevalence of coronary artery calcification assessed by multislice computed tomography

Warfarin inhibits the synthesis and function of matrix Gla protein, a vitamin K-dependent protein, which is a potent inhibitor of tissue calcification. We had earlier reported the association of warfarin use with valvular calcification in patients with nonvalvular atrial fibrillation. The aim of our present study was to investigate the association of warfarin use with the presence and severity of coronary artery calcification. A total of 233 patients underwent computed tomography scan (CT) at our institution for the assessment of coronary artery calcium score (CACS). Of 233 patients, the mean age was 63 years, 28 patients (12%) were treated with warfarin, and 205 patients (88%) were not on warfarin. Based on their total CACS, the patients were subsequently stratified into 59 with no coronary calcium (CACS = 0), 63 with low CACS (1-100), 49 with moderate CACS (101-400), 33 with severe CACS (410-1000), and 29 with very severe CACS (>1000). The χ test and Student t-test were used for the comparison of categorical and continuous variables, respectively, between warfarin users and nonusers. Using the variables age, gender, race, smoking, hypertension, diabetes, dyslipidemia, glomerular filtration rate, calcium-phosphorus product, alkaline phosphatase, use of aspirin, beta blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and statins, stepwise logistic regression analysis did not show any association of coronary calcification with use of warfarin. In our study, warfarin use was not associated with a higher prevalence or severity of CACS assessed by coronary computed tomography.