title: Warfarin versus aspirin for prevention of cognitive decline in atrial fibrillation: randomized controlled trial (Birmingham Atrial Fibrillation Treatment of the Aged Study).
abstract: OBJECTIVE
  Atrial fibrillation is associated with decline of cognitive function. Observational evidence suggests that anticoagulation might protect against this decline. We report the first randomized controlled trial evidence on the effect of anticoagulation on cognitive function in elderly patients with atrial fibrillation.
  
  
  METHODS
  A total of 973 patients aged≥75 years with atrial fibrillation were recruited from primary care and randomly assigned to warfarin (n=488; target international normalized ratio, 2-3) or aspirin (n=485; 75 mg/d). Neither participants nor investigators were masked to group assignment. Follow-up was for a mean of 2.7 years (SD, 1.2). Cognitive outcome was assessed using the Mini-Mental State Examination at 9-, 21-, and 33-month follow-up. Participants who had a stroke were censored from the analysis, which was by intention to treat with imputation for missing data.
  
  
  RESULTS
  There was no difference between mean Mini-Mental State Examination scores in people assigned to warfarin or aspirin at 9 or 21 months. At 33-month follow-up, there was a nonsignificant difference of 0.56 in favor of warfarin that decreased to 0.49 (95% confidence interval, -0.01 to 0.98) after imputation.
  
  
  CONCLUSIONS
  We found no evidence that anticoagulation confers clinically important protection over aspirin against cognitive decline as measured by the Mini-Mental State Examination in atrial fibrillation in the first 33 months of treatment other than that provided by preventing clinical stroke.
  
  
  BACKGROUND
  http://www.controlled-trials.com. Unique identifier: ISRCTN89345269.
authors.affiliation: From the Primary Care Unit, Strangeways Laboratory, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom (N.M., J.M.); Primary Care Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom (A.R., K.F., D.F.); University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom (G.Y.H.L.); and Department of Primary Care Health Sciences, New Radcliffe House, Radcliffe Observatory Quarter, University of Oxford, Oxford, United Kingdom (F.D.R.H.).
authors.forename: Nahal
authors.initials: N
authors.lastname: Mavaddat
authors.forename: Andrea
authors.initials: A
authors.lastname: Roalfe
authors.forename: Kate
authors.initials: K
authors.lastname: Fletcher
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: F D Richard
authors.initials: FD
authors.lastname: Hobbs
authors.forename: David
authors.initials: D
authors.lastname: Fitzmaurice
authors.forename: Jonathan
authors.initials: J
authors.lastname: Mant
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology; D000925:Anticoagulants / Q000008:administration & dosage / Q000494:pharmacology*; D001241:Aspirin / Q000008:administration & dosage / Q000494:pharmacology*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D003072:Cognition Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology / Q000517:prevention & control; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D014859:Warfarin; D001241:Aspirin
keywords: aspirin; atrial fibrillation; cognition; warfarin