D-Dimer Levels in Combination with Clinical Risk Factors Can Effectively Predict Subsequent Thromboembolic Events in Patients with Atrial Fibrillation during Oral Anticoagulant Therapy

Objectives: Atrial fibrillation (AF) is associated with hemostatic abnormality and increased risk of thromboembolic events. The aim of the present study was to evaluate whether elevated D-dimer levels in combination with clinical risk factors can adequately predict subsequent thromboembolic events in patients with AF. Method: This was a post hoc analysis of the single-center, prospective observational study. Consecutive patients with nonvalvular AF (245 patients, 74 +/- 9 years) treated with warfarin were included. D-dimer levels were measured in combination with clinical risk factors to assess the relationship of this parameter with subsequent thromboembolic events. Results: D-dimer levels were elevated (>= 0.5 mu g/ml) in 55 (22%) patients. During an average follow-up time of 756 +/- 223 days, 9 (1.8%/year) thromboembolic events occurred. Cox proportional hazard analysis showed that elevated D-dimer levels (hazard ratio, HR, 14.3, p<0.01) as well as high CHADS(2) score (>= 3; HR 9.43, p<0.01) was associated with thromboembolic events. C-statistic improved to 0.848 from 0.781 when D-dimer level was added to the predictor model based on CHADS(2) score. Elevated D-dimer levels also predicted thromboembolic events in the subgroup of patients with high CHADS(2) score (n = 76, HR 12.1, p = 0.021). Conclusion: CHADS(2) scores and D-dimer level can be a useful marker of subsequent thromboembolic events in patients with AF during oral anticoagulant therapy and combination of these can effectively predict thromboembolic events. Copyright (C) 2010 S. Karger AG, Basel