PURPOSE: The aim of this study was to assess whether warfarin is overused or underused in atrial fibrillation(af) patients.
METHODS: One hundred seventy five patients, who was followed at our clinic between January 2010 and January 2011,were investigated on CHADs2 score, associated comorbidities and anticoagulation. The decision for anticoagulation was made by the attending physicions at outpatient clinic, and no intervention to guide anticoagulant therapy was made.
RESULTS: The mean age was 74.4(SD 8.8, range 49 to 97),34.3% female. 31(17.7%) had cardiac comodity,35(20.0%) had diabetes mellitus,120(60.6%) hypertension,29(16.6%) prior stroke. Mean CHADS2 score was 2.4(SD 1.4, range 0 to 6). The CHADS2 score was 0 in 13(7.4%), 1 in 32(17.7%), 2 in 42(24.9%),3 in 42(24.0%) and a CHADS2 score of ≧4 34(19.5%). Warfarin was prescribed 1n 121(75.0%), and in 8/13(61.5%) with CHADS" score of 0, 16/31(58.0%) with a CHADS2 score ,of 1, 40/57(70.2%) with a CHADS2 score of 2.31/40(77.5%) in a CHADS2 score of 3 and 24/32(75.0%) with a CHADS2 score of 4-6. Among 175 patients,110(62.9%) had permanet af and 65(37.1%) had intermittent af. Among 34 intermittent af patients with combined CHADS2≧2 and age≧75, 18/34(52.95) were not on warfarin, while 11/66(16.7%) permanent af patients were not on warfarin.(p: less than 0.05,comparing intermittent af with permanent af). Among 45 intermittent af patients with CHADS2 score≧2,33/45(73/4%) were not on warfarin. Of the reasons for not on warfarin, 2(6.1%) was due to prior hemorrhagic event and 12(18.5%) refusal,9(27.6%) discontinued after self decision, while remaining 10(30.3%) had no documented contraindication.
CONCLUSIONS: Warfarin was inappropriately overused on low risk patients with CHADS2 score≦1, and underused in high risk intermittent af patiemts combined CHADS2 score≧2 and age≧75.
CLINICAL IMPLICATIONS: The results may be useful to improve appropriate warfarin use and patients education.
DISCLOSURE: The following authors have nothing to disclose: Nobuyuki Anzai, Rieko Mitobe, Makiko Anzai, Kei Goto
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