title: Increased vascular calcification in patients receiving warfarin.
abstract: OBJECTIVE
  Matrix gla protein is a vitamin K-dependent inhibitor of medial arterial calcification whose synthesis and activity are blocked by warfarin. Warfarin induces arterial calcification in experimental models, but whether this occurs in humans is unclear. This was addressed by examining breast arterial calcification, which is exclusively medial and easily identified on mammograms.
  
  
  RESULTS
  Screening mammograms from women with current, past, or future warfarin use were examined for the presence of arterial calcification and compared with mammograms obtained in untreated women matched for age and diabetes mellitus. Women with a serum creatinine >2.0 mg/dL or a history of end-stage renal disease were excluded. In 451 women with mammograms performed after ≥1 month of warfarin therapy, the prevalence of arterial calcification was 50% greater than in 451 untreated women (39.0% versus 25.9%; P<0.0001). However, in 159 mammograms performed before warfarin therapy, the prevalence of arterial calcification was not increased (26.4% versus 25.8%). The increased prevalence varied with duration of treatment, from 25.0% for <1 year to 74.4% for >5 years. In a multivariable logistic model, only age and duration of warfarin, but not the period of time after stopping warfarin, were significant determinants of arterial calcification in women with current or past warfarin use.
  
  
  CONCLUSIONS
  The prevalence of breast arterial calcification is increased in women with current or past warfarin use independent of other risk factors and conditions predating warfarin use. This effect appears to be cumulative and may be irreversible.
authors.affiliation: From the Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA (E.T., K.H.H., C.O.N.); and Department of Internal Medicine, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, Korea (K.H.H).
authors.forename: Ekamol
authors.initials: E
authors.lastname: Tantisattamo
authors.affiliation: From the Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA (E.T., K.H.H., C.O.N.); and Department of Internal Medicine, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, Korea (K.H.H).
authors.forename: Kum Hyun
authors.initials: KH
authors.lastname: Han
authors.affiliation: From the Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA (E.T., K.H.H., C.O.N.); and Department of Internal Medicine, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, Korea (K.H.H). woneill@emory.edu.
authors.forename: W Charles
authors.initials: WC
authors.lastname: O'Neill
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D001941:Breast Diseases / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000453:epidemiology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004334:Drug Administration Schedule; D005260:Female; D005845:Georgia / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008327:Mammography; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D012307:Risk Factors; D013997:Time Factors; D061205:Vascular Calcification / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000453:epidemiology; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: anticoagulation; matrix proteins; vascular calcification