D-dimer levels in combination with clinical risk factors can effectively predict subsequent thromboembolic events in patients with atrial fibrillation during oral anticoagulant therapy.
OBJECTIVE
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.


METHODS
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 μg/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 CHADS₂ 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 CHADS₂ score. Elevated D-dimer levels also predicted thromboembolic events in the subgroup of patients with high CHADS₂ score (n = 76, HR 12.1, p = 0.021).


CONCLUSIONS
CHADS₂ 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.
Sadanaga
Tsuneaki
T
Division of Cardiology, Ueki Hospital, Kumamoto, Japan. kamefu@rb3.so-net.ne.jp
Kohsaka
Shun
S
Ogawa
Satoshi
S
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood*; D018572:Disease-Free Survival; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D013923:Thromboembolism / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology
D000925:Anticoagulants; D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D