title: Occurrence and characteristics of stroke events in the Atrial Fibrillation Follow-up Investigation of Sinus Rhythm Management (AFFIRM) study.
abstract: BACKGROUND
  Atrial fibrillation (AF) is a risk factor for stroke, especially when accompanied by other high-risk cardiovascular predictors. The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Study was a multicenter comparison of high-risk patients with AF who were randomized to either a sinus rhythm control or a rate control strategy.
  
  
  METHODS
  Physicians were encouraged to continue anticoagulation therapy for their patients. Patients in the sinus rhythm control group could stop warfarin sodium therapy after 4 (preferably a minimum of 12) weeks if they maintained sinus rhythm while receiving an antiarrhythmic drug.
  
  
  RESULTS
  The AFFIRM Study enrolled 4060 patients. Mortality was the same in both groups. Two hundred eleven patients (8.2%) had a stroke event. Ischemic stroke occurred in 157 patients (6.3%), primary intraparenchymal hemorrhage in 34 (1.2%), and subdural or subarachnoid hemorrhage in 24 (0.8%). The most frequently determined ischemic stroke mechanism was cardioembolic (35/71 [49%]). Treatment assignment had no significant effect on the occurrence of ischemic stroke. Patients in AF at the time of the stroke event had a 60% greater chance of having an ischemic stroke, and those taking warfarin at the time of follow-up had a 69% decrease in the risk of having an ischemic stroke.
  
  
  CONCLUSIONS
  In the AFFIRM Study, stroke rates were not significantly different in the rate control and sinus rhythm control arms. However, several clinical and therapeutic variables were associated with stroke risk. In patients with a history of AF at high risk for stroke or death, the presence of AF increases the risk of having a stroke, and warfarin therapy reduces the risk of having a stroke. The beneficial effect of warfarin therapy is seen not only in patients in AF but also in patients with a history of AF but who presumably remain in sinus rhythm.
authors.affiliation: University of Texas Health Science Center, San Antonio, USA. Sherman@uthscsa.edu
authors.forename: David G
authors.initials: DG
authors.lastname: Sherman
authors.forename: Soo G
authors.initials: SG
authors.lastname: Kim
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Boop
authors.forename: Scott D
authors.initials: SD
authors.lastname: Corley
authors.forename: John P
authors.initials: JP
authors.lastname: Dimarco
authors.forename: Robert G
authors.initials: RG
authors.lastname: Hart
authors.forename: L Julian
authors.initials: LJ
authors.lastname: Haywood
authors.forename: Keith
authors.initials: K
authors.lastname: Hoyte
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kaufman
authors.forename: Michael H
authors.initials: MH
authors.lastname: Kim
authors.forename: Elaine
authors.initials: E
authors.lastname: Nasco
authors.forename: Albert L
authors.initials: AL
authors.lastname: Waldo
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D002170:Canada / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D014481:United States / Q000453:epidemiology; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin