Accumulation of risk factors enhances the prothrombotic state in atrial fibrillation.
BACKGROUND
The present study was conducted to investigate the relation between the accumulation of the risk factors of thromboembolism and the levels of hemostatic markers in patients with nonvalvular atrial fibrillation (NVAF).


METHODS
Five hundred ninety-one NVAF patients and 129 control subjects were categorized into low, moderate or high risk of thromboembolism, according to CHADS(2) index. One point each was given to patients with advanced age (> or =75 years), hypertension, congestive heart failure, and diabetes mellitus, and 2 points, to those with prior ischemic stroke or transient ischemic attack. Patients with CHADS(2) score of 0, 1 or 2, and > or =3 were classified as low, moderate and high risk, respectively. Levels of hemostatic markers (platelet factor 4, beta-thromboglobulin, prothrombin fragment F1+2 and D-dimer) were determined.


RESULTS
Of 591 patients with NVAF, 302 were treated with warfarin (mean international normalized ratio 1.88). D-dimer levels increased as the risk level increased irrespective of warfarin use. Particularly, NVAF patients without receiving warfarin (n=289) had significantly higher D-dimer levels than control patients (e.g., for high risk patients, 175+/-144 vs 75+/-87 ng/ml, p<0.001), while NVAF patients receiving warfarin had intermediate levels (136+/-156 ng/ml). F1+2 levels increased as the risk level increased, and were significantly suppressed by warfarin. Levels of markers of platelet activation (platelet factor 4 and beta-thromboglobulin) were increased in NVAF patients but not affected by the risk level.


CONCLUSIONS
Coagulation and fibrinolytic activity is increased along with the accumulation of the risk factors of thromboembolism in NVAF patients.
Ohara
Kazumasa
K
Second Department of Internal Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
Inoue
Hiroshi
H
Nozawa
Takashi
T
Hirai
Tadakazu
T
Iwasa
Atsushi
A
Okumura
Ken
K
Lee
Jong-Dae
JD
Shimizu
Akihiko
A
Hayano
Motonobu
M
Yano
Katsusuke
K
D017677:Age Distribution; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology*; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010978:Platelet Factor 4 / Q000032:analysis; D011336:Probability; D011516:Prothrombin / Q000032:analysis; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D016019:Survival Analysis; D013923:Thromboembolism / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D014859:Warfarin / Q000627:therapeutic use; D001620:beta-Thromboglobulin / Q000032:analysis
D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; D001620:beta-Thromboglobulin; C036309:fibrin fragment D; D010978:Platelet Factor 4; D014859:Warfarin; D011516:Prothrombin