Warfarin Use and Risk of Valvular Calcification

Lerner R G, Sekhri A, Palaniswamy C.  Warfarin Use and Risk of Valvular Calcification.  Journal of Coagulation Disorders, July 2010; 2(2):  57-62

REVIEW ARTICLE

Robert G Lerner, Arunabh Sekhri and Chandrasekar Palaniswamy

Affiliation: Department of Medicine, Division of Hematology & Oncology, New York Medical College, Valhalla, NY, USA


ABSTRACT

Vitamin K is a micronutrient that is required for the activity of various biologically active proteins. Apart from clotting factors, these vitamin K-dependent proteins include regulatory proteins such as protein C, protein S, protein Z, osteocalcin, growth arrest-specific gene 6 protein (Gas6), and matrix Gla protein (MGP). MGP has glutamic acid residues that are gamma-carboxylated by vitamin K-dependent gamma-carboxylase, which enables it to inhibit calcification. Warfarin, being a vitamin K antagonist, inhibits this process and has thus been associated with calcification in various animal and human studies. Although no specific guidelines are presently available to prevent or treat this less recognized side-effect, stopping warfarin and using an alternative anticoagulant seems to be a reasonable therapeutic option. Newer anticoagulants such as dabigatran and rivaroxaban offer promise as future therapeutic options in such a scenario. Agents such as atorvastatin, alendronate, osteoprotegerin, and vitamin K to prevent or treat warfarin-induced calcification are under study.

Keywords: warfarin, valvular calcification, vascular calcification, matrix Gla protein, y-carboxylation, vitamin K

Correspondence: Robert G Lerner, Department of Medicine, Division of Hematology & Oncology, New York Medical College, Valhalla, NY 10595, USA. Tel: M-914-594-4979; Fax: M-914-594-4396; e-mail: ROBERT_LERNER@nymc.edu