title: [Hypercoagulability in atrial fibrillation and its relationship with risk factors for systemic embolism].
abstract: 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.
authors.affiliation: Departamentos de Enfermedades Cardiovasculares, Hospital Clínico de la Pontificia Universidad Católica de Chile.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Pérez
authors.forename: Ramón
authors.initials: R
authors.lastname: Corbalán
authors.forename: Mónica
authors.initials: M
authors.lastname: Acevedo
authors.forename: Jaime
authors.initials: J
authors.lastname: Pereira
authors.forename: Sandra
authors.initials: S
authors.lastname: Braun
authors.forename: Jorge
authors.initials: J
authors.lastname: Tapia
authors.forename: Albrecht
authors.initials: A
authors.lastname: Kramer
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Lira
authors.forename: Isidro
authors.initials: I
authors.lastname: Huete
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Sepúlveda
authors.forename: Daniel
authors.initials: D
authors.lastname: Springmüller
mesh_terms: 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
chemical_list: D000991:Antithrombins; D001779:Blood Coagulation Factors