Original Article Frequency and predictors of bleeding complications associated with anti-coagulant therapy using dabigatran in Japanese patients with atrial fibrillation

Background: Few data exist regarding frequency and predictors of bleeding complications associated with anticoagulant therapy using dabigatran in Japanese patients with atrial fibrillation (AF). Methods and Results: We retrospectively studied 184 patients with AF who were administered dabigatran from April 2011 to August 2012 in our institution. Twenty-eight patients (15%) developed some type of bleeding complication. In the Bleeding group, age, CHADS 2 and HAS-BLED score were higher (75 vs. 71 years, p=0.067, 2.7 vs. 1.9, p=0.006 and 2.3 vs. 1.8, p=0.01, respectively), hemoglobin concentration was lower (13.1 vs. 13.7 g/dL, p=0.04), casual activated partial thromboplastin time (APTT) was longer (60.2 vs. 47.4 sec., p<0.0001) and frequency of aspirin use was higher (29 vs. 15%, p=0.09) than those in the Non-bleeding group. Multivariate regression analysis showed that casual APTT was an independent significant predictor of any type of bleeding complications (β=0.431, p<0.0001). Moreover, casual APTT (β=0.359, p=0.049), pre-existing anemia (β=0.457, p=0.02) and aspirin use (β=0.597, p=0.02) were significant predictors of major bleeding. ROC analysis showed that casual APTT exhibited 83.3% sensitivity and 72.5% specificity as predictors of major bleeding and its cut-off value was 54.7 sec. Conclusion: Casual APTT level can serve as a predictor of bleeding complications, while pre-existing anemia and aspirin use may be associated with major bleeding in patients with AF treated with dabigatran.