Novel Dielectric Coagulometer Identifies Hypercoagulability in Patients with a High CHADS2 Score without Atrial Fibrillation.
BACKGROUND
Recent reports showed that the CHADS2 score predicted the risk of strokes in patients without atrial fibrillation (AF). Although the hypercoagulability may contribute to the thrombogenesis, it has not been fully investigated due to a lack of a sensitive evaluation modality. Recently a novel dielectric blood coagulometry (DBCM) was invented for evaluating the coagulability by measuring the temporal change in whole blood dielectric permittivity.


OBJECTIVE
We evaluated the utility of the DBCM for identifying the coagulability.


METHODS
For fundamental experiments, 133 citrated blood samples were drawn from subjects with or without heparin administration. A DBCM analysis was performed to find the adequate coagulation index, and to delineate its measurement range by adding recombinant human tissue factor (TF) or heparin. Then the coagulability was assessed by DBCM and conventional coagulation assays in 84 subjects without AF, who were divided into 3 groups by their CHADS2 score. Another 17 patients who received warfarin were also assessed by DBCM to evaluate the effect of anticoagulants.


CONCLUSIONS
We calculated the derivative of the dielectric permittivity change after recalcification, and extracted the end of acceleration time (EAT) as a novel index. The EAT showed a dose-dependent shortening with the addition of serial dilutions of TF (×10-2 to ×10-4), and a dose-dependent prolongation with the addition of heparin (0.05 to 0.15 U/ml). The EAT was significantly shorter in the higher CHADS2 score group (19.8 ± 4.8, 18.6 ± 3.1, and 16.3 ± 2.7 min in the CHADS2 = 0, 1, and ≥2 groups, respectively, p = 0.0065 by ANOVA). Patients receiving warfarin had a significantly more prolonged EAT than those without warfarin (18.6±4.2 vs. 25.8±7.3 min, p <0.001). DBCM detected the whole blood coagulability with a high sensitivity. Subjects with higher CHADS2 scores exhibited hypercoagulability without AF.
Department of Biofunctional Informatics, Tokyo Medical and Dental University, Tokyo, Japan.
Yuki
Y
Hasegawa
Department of Biofunctional Informatics, Tokyo Medical and Dental University, Tokyo, Japan.
Satomi
S
Hamada
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Takuro
T
Nishimura
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Takeshi
T
Sasaki
Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Yusuke
Y
Ebana
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Mihoko
M
Kawabata
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Masahiko
M
Goya
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Mitsuaki
M
Isobe
Department of Laboratory Molecular Genetics of Hematology, Tokyo Medical and Dental University, Tokyo, Japan.
Takatoshi
T
Koyama
Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
Tetsushi
T
Furukawa
Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
Kenzo
K
Hirao
Department of Biofunctional Informatics, Tokyo Medical and Dental University, Tokyo, Japan.
Tetsuo
http://orcid.org/0000-0003-3582-6104
T
Sasano
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood; D001780:Blood Coagulation Tests / Q000295:instrumentation / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019851:Thrombophilia / Q000097:blood*