title: Early mechanical mitral valve thrombosis in a patient with warfarin resistance.
abstract: Warfarin, an oral anticoagulant, is the therapy of choice to maintain anticoagulation. An individual requiring five- to 20-fold higher dosage than average for anticoagulation may be considered as having resistance to warfarin. In order to evaluate a subtherapeutic response to high-dose warfarin, the clinician must consider many possible causes of resistance, such as non-compliance, drug interactions, or pharmacokinetic changes. When these factors have been eliminated, an hereditary warfarin resistance might be considered responsible. The case is reported of a 49-year-old woman who received warfarin after mitral valve replacement and experienced mechanical mitral valve thrombosis due to inadequate anticoagulation, possibly caused by warfarin resistance.
authors.affiliation: Turkiye Yuksek Ihtisas Hospital, Department of Cardiology, Ankara, Turkey. drasaatciyasar@yahoo.com
authors.forename: Ayse Saatci
authors.initials: AS
authors.lastname: Yasar
authors.forename: Yucel
authors.initials: Y
authors.lastname: Balbay
authors.forename: Orhan
authors.initials: O
authors.lastname: Maden
authors.forename: Hatice
authors.initials: H
authors.lastname: Sasmaz
mesh_terms: D000925:Anticoagulants / Q000097:blood / Q000627:therapeutic use; D001705:Bioprosthesis; D004351:Drug Resistance; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D012086:Reoperation; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D014463:Ultrasonography; D014859:Warfarin / Q000097:blood / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin