title: Atrial fibrillation: estimated excess rate of stroke due to lacking adherence to guidelines.
abstract: OBJECTIVE
  Many patients with atrial fibrillation (AF), risk factors for stroke and no obvious contraindications do not receive oral anticoagulation. Estimations of the increased rate of stroke due to neglected anticoagulation, particularly in an elderly, non-selected population, are unknown.
  
  
  METHODS
  Consecutive patients with paroxysmal or permanent atrial fibrillation admitted to the medical or surgical department of our hospital for any reason were studied. Risk factors for stroke and contraindications for anticoagulation were recorded. Estimations of the increased rate of cerebrovascular events due to neglected anticoagulation were based on data of a large meta-analysis. Patients were further stratified into different age and risk groups.
  
  
  RESULTS
  484 patients with a mean age of 75 (12) years were studied, 45% were female. 237 patients had no oral anticoagulation at hospital discharge, despite guideline recommendations. Contraindications for anticoagulation were found in 85 (36%) of these patients, resulting in 152 patients with neglected anticoagulation (31% of all patients with AF). We estimated that, if all those patients would have been treated according to guidelines, 7.4 strokes per year could be prevented in the study population. The estimated rate of preventable events was 4.9%/year (7.4/152).
  
  
  CONCLUSIONS
  With better adherence to guidelines for oral anticoagulation in patients with atrial fibrillation and risk factors for stroke, a significant number of strokes could be prevented.
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland.
authors.forename: Barbara S
authors.initials: BS
authors.lastname: Zehnder
authors.forename: Beat A
authors.initials: BA
authors.lastname: Schaer
authors.forename: Urs
authors.initials: U
authors.lastname: Jeker
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Cron
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D000075202:Contraindications; D017723:Drug Utilization Review; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006785:Hospitals, University / Q000592:standards; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced; D008297:Male; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control*; D013557:Switzerland
chemical_list: D000925:Anticoagulants