title: Prevalence of atrial fibrillation and antithrombotic prophylaxis in emergency department patients.
abstract: OBJECTIVE
  The emergency department (ED), as the point of first medical contact for many complaints referable to atrial fibrillation (AF) and a common source of primary care, occupies a unique position to identify AF patients at risk of stroke. This study evaluates that potential by determining the prevalence of AF in an ED population and assessing antithrombotic use in those patients with recurrent AF.
  
  
  METHODS
  This was a multicenter, retrospective, cross-sectional study of consecutive records of ED patients with AF identified by ECG between January and June 1998. American Heart Association and modified Stroke Prevention in Atrial Fibrillation criteria established high-risk patients and contraindications to anticoagulation, respectively.
  
  
  RESULTS
  We identified 866 records with ECG-proven AF in 78 787 patient visits for an estimated prevalence of 1.10% (95% CI, 1.03 to 1.17). We found that 556 records had a prior history of AF; of these, 221 (40%) used warfarin alone, 155 (28%) had antiplatelet therapy alone, 28 (5%) used both, and 152 (27%) had no antithrombotic therapy identified. Sixty-eight patients (12%; 95% CI, 0.10 to 0.15) were warfarin eligible and without antithrombotic therapy. An additional 64 (12%; 95% CI, 0.09 to 0.14) had antiplatelet therapy alone. In warfarin-eligible patients, no differences were identified between the anticoagulated and nonanticoagulated groups on the basis of age, sex, or race. Of patients on warfarin with a measured international normalized ratio, 61% (95% CI, 0.55 to 0.67) were outside the AHA-recommended range of 2.0 to 3.0.
  
  
  CONCLUSIONS
  AF is a common finding in an ED population. Many are warfarin eligible and untreated or undertreated. Methods to increase anticoagulant use in this at-risk population warrant further investigation.
authors.affiliation: Department of Emergency Medicine, University of Michigan, Ann Arbor 48109, USA. phillip.scott@umich.edu
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Scott
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Pancioli
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Davis
authors.forename: Shirley M
authors.initials: SM
authors.lastname: Frederiksen
authors.forename: John
authors.initials: J
authors.lastname: Eckman
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D000075202:Contraindications; D003430:Cross-Sectional Studies; D004363:Drug Utilization / Q000706:statistics & numerical data; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D015995:Prevalence; D044469:Racial Groups; D012008:Recurrence; D012189:Retrospective Studies; D017678:Sex Distribution; D020521:Stroke / Q000517:prevention & control*; D014859:Warfarin / Q000008:administration & dosage
chemical_list: D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin