title: Lysability of fibrin clots is a potential new determinant of stroke risk in atrial fibrillation.
abstract: BACKGROUND
  Atrial fibrillation increases the risk of ischemic stroke, but the risk depends on other factors as well. Present risk stratification schemes use age and co-morbidities, but not biochemical markers. We investigated the hypothesis that the formation, structure and lysability of fibrin clots are potential determinants of stroke risk in patients with atrial fibrillation.
  
  
  METHODS
  A total of 179 patients with atrial fibrillation in stable anticoagulant treatment were included. Thirty-two had a previous ischemic stroke. We measured thrombin generation, plasma concentrations of fibrinogen and C-reactive protein and analysed fibrin structure and lysability by turbidity. Fibrinolytic capacity was measured using the euglobulin fraction of plasma expressed in terms of t-PA equivalents (IU/ml).
  
  
  RESULTS
  The patients with previous stroke had a slightly higher burden of co-morbidities compared with the remaining patients as indicated by the CHA2DS2-VASc score, but no significant differences were found regarding age, fibrinogen concentration, C-reactive protein, thrombin generation or fibrinolytic capacity. Furthermore, the patients with previous stroke had a higher mass/length ratio of fibrin fibers (5.5 vs. 5.1 x10(12) Da/cm, p=0.044) and an increased lysability (79.3 vs. 55.3%, p<0.01).
  
  
  CONCLUSIONS
  The higher lysability of fibrin clots in atrial fibrillation patients with previous stroke is most likely a result of a difference in fibrin fiber properties. An increased lysability may increase the risk of embolization of clots formed in the atria, and therefore fibrin clot structure seems to be a determinant of stroke risk in atrial fibrillation.
authors.affiliation: Unit for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark; Department of Clinical Biochemistry, Hospital of South West Denmark, Esbjerg, Denmark. Electronic address: jskov@health.sdu.dk.
authors.forename: Jane
authors.initials: J
authors.lastname: Skov
authors.affiliation: Unit for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark; Department of Clinical Biochemistry, Hospital of South West Denmark, Esbjerg, Denmark.
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: Sidelmann
authors.affiliation: Unit for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark; Department of Clinical Biochemistry, Hospital of South West Denmark, Esbjerg, Denmark.
authors.forename: Else-Marie
authors.initials: EM
authors.lastname: Bladbjerg
authors.affiliation: Unit for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark; Department of Clinical Biochemistry, Hospital of South West Denmark, Esbjerg, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Jespersen
authors.affiliation: Unit for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark; Department of Clinical Biochemistry, Hospital of South West Denmark, Esbjerg, Denmark.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Gram
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000097:blood / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000032:analysis; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005337:Fibrin / Q000737:chemistry / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D005342:Fibrinolysis / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D013917:Thrombin / Q000378:metabolism
chemical_list: D000925:Anticoagulants; D015415:Biomarkers; D005337:Fibrin; D005340:Fibrinogen; D002097:C-Reactive Protein; D013917:Thrombin
keywords: Atrial fibrillation; Fibrin structure; Fibrinolysis; Stroke