[Hypercoagulability in atrial fibrillation and its relationship with risk factors for systemic embolism].
BACKGROUND
Atrial fibrillation is associated to a high risk of systemic embolism and to hypercoagulability.


OBJECTIVE
To evaluate the activation of the coagulation cascade through determinations of the thrombin-antithrombin complex in patients with atrial fibrillation and to correlate this data with the clinical and echocardiographic risk factors for systemic embolism.


METHODS
In 53 patients with atrial fibrillation plasma levels of the thrombin-antithrombin complex were determined on admission to a coronary care unit and 30 days later. Using a univariate and multiple regression analysis, the association basal thrombin-antithrombin with the duration of the arrhythmia, age over 70 years, previous use of antiplatelet agents, history of hypertension, mitral valve disease, diabetes, heart failure, previous systemic embolism, left atrial diameter and the presence of spontaneous contrast echo or thrombus in the left atrial appendage, was studied.


RESULTS
Basal thrombin-antithrombin values were 40.1 +/- 69 mg/L (Median 8.34 [3.0-47.5]) compared to 2.7 +/- 3.3 mg/L in healthy controls (p < 0.001). No significant correlation was found between activation of the coagulation cascade and risk factors for systemic embolism. There were no significant differences in thrombin-antithrombin values between patients with chronic or paroxysmal atrial fibrillation (29.5 +/- 43 mg/L and 49.4 +/- 83 mg/L respectively). Mean thrombin-antithrombin values in patients under antiplatelet agents were lower than in those without treatment (17.3 +/- 43 vs 66.8 +/- 127 mg/L; p = 0.018).


CONCLUSIONS
The activation of the coagulation cascade in patients with atrial fibrillation was confirmed. However, no association of this activation with well known clinical and echocardiographic risk factors for systemic embolism, was found. Previous antiplatelet treatment prevented a higher activation of the coagulation cascade.
Pérez
Luis A
LA
Departamentos de Enfermedades Cardiovasculares, Hospital Clínico de la Pontificia Universidad Católica de Chile.
Corbalán
Ramón
R
Acevedo
Mónica
M
Pereira
Jaime
J
Braun
Sandra
S
Tapia
Jorge
J
Kramer
Albrecht
A
Lira
M Teresa
MT
Huete
Isidro
I
Sepúlveda
Gonzalo
G
Springmüller
Daniel
D
D000368:Aged; D000704:Analysis of Variance; D000991:Antithrombins / Q000032:analysis*; D001281:Atrial Fibrillation / Q000097:blood* / Q000150:complications; D001777:Blood Coagulation; D001779:Blood Coagulation Factors / Q000378:metabolism*; D016022:Case-Control Studies; D020147:Coagulation Protein Disorders / Q000209:etiology*; D017548:Echocardiography, Transesophageal; D004617:Embolism / Q000097:blood* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors
D000991:Antithrombins; D001779:Blood Coagulation Factors