title: Atrial fibrillation - patients at high risk for cerebral embolism.
abstract: OBJECTIVE
  Patients with atrial fibrillation (AF) have a risk of cerebral embolism. Echocardiographic parameters elevate this risk significantly. However, there is little knowledge about the long-term fate and the rate of clinically silent cerebral embolism under continued oral anticoagulation. The aims of our study were to assess prognosis of patients with AF and determine a high risk group with an increased risk of cerebral embolism under oral anticoagulation.
  
  
  METHODS
  Consecutive patients with persistent or permanent AF and left atrial (LA) thrombi, dense spontaneous echo contrast (SEC) and/or reduced LA appendage peak emptying velocities (LAAv) were included in the study (N = 128). Patients with AF and without echocardiographic risk factors (N = 114) served as controls. All patients were examined with transesophageal echocardiography, cranial magnetic resonance imaging and clinically during a period of three years.
  
  
  RESULTS
  During the three-year follow-up period 6 (5%) of the high risk patients had cerebral embolism with neurological deficits. 4 (3%) patients died due to embolic events and 17 (13%) patients had silent embolism as documented on MRI. In the control group 8 (7%) patients had embolic events (n = 1 clinically apparent and n = 7 silent embolism) documented on MRI, one was clinically apparent. Study patients with an event had more commonly previous thromboembolism (p < 0.0001).
  
  
  CONCLUSIONS
  Patients with peristent or permanent AF and LA thrombi, dense SEC or reduced LAAv have an explicitly increased risk of cerebral embolism (21%) despite oral anticoagulation. Previous thromboembolic event is another important predictor for an event.
authors.affiliation: Department of Medicine-Cardiology, University of Bonn, Germany. bernhardt@cardiovasc-mri.com
authors.forename: P
authors.initials: P
authors.lastname: Bernhardt
authors.forename: H
authors.initials: H
authors.lastname: Schmidt
authors.forename: T
authors.initials: T
authors.lastname: Sommer
authors.forename: B
authors.initials: B
authors.lastname: Lüderitz
authors.forename: H
authors.initials: H
authors.lastname: Omran
mesh_terms: D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015897:Comorbidity; D017548:Echocardiography, Transesophageal / Q000706:statistics & numerical data; D005260:Female; D005858:Germany; D006801:Humans; D015994:Incidence; D020766:Intracranial Embolism / Q000175:diagnosis* / Q000453:epidemiology*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors