ABSTRACT
Objective To evaluate the level of international normalized ratio (INR) stability and explore the relationship between INR and complication.Methods One hundred and twenty-nine patients with nonvalvular atrial fibrillation (NVAF) and receiving warfarin anticoagulation treatment were collected from May 2005 to May 2010.INR stability in all patients was calculated.INR stability was defined as the ratio of INR check times within the target range over the total INR check times in the same time period.Results The median time of follow-up was 1.8 years.During the follow-up period,the total effective monitoring value of INR was 2574 times (INR was 0.9-6.0),in which 1085 times (42.2％) was outside the anticoagulation target range (INR was 2.0-3.0).INR stability was (60.9 ± 14.9)％.INR stability had significant difference between patients with or without stroke [(61.2 ± 15.0)％ vs.(53.3 ± 4.9)％] (P ＜ 0.05).The factors effecting warfarin anticoagulation intensity were analyzed:unexplained reason (573 times,52.8％),poor medication compliance (214 times,19.7％),changing food structure (143 times,13.2％),the western medicine(109 times,10.0％),the traditional Chinese medicine (12 times,1.1％) and intaking of spirits (34 times,3.1％).Conclusions During warfarin anticoagulation treatment,INR stability ＞ 60％ is safe and effective.Among the known factors which effect anticoagulation stability of warfarin,medication compliance is still the main factor.