Atrial fibrillation: a previous stroke or TIA and poor LV function increased the risk of an ischaemic stroke

Clinical bottom line (level 2b)

  1. One in fourteen patients with atrial fibrillation who were not anticoagulated had a stroke within 2 years.
  2. The risk was increased with
    • a previous stroke or transient ischaemic attack
    • moderate to severe LV dysfunction
    • a history of heart failure
    • a history of diabetes
    • increasing age
Atrial Fibrillation Investigators et al: Archives of Internal Medicine 1998; 158 : 1316-1320
Expires November 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: acute hospitals, USA

1066 patients (aged mean 67, 78% male) with atrial fibrillation randomised to placebo (or aspirin) in 3 clinical trials

Factors studied:
  • age, history of hypertension, stroke or TIA, diabetes, heart failure, moderate to severe LV dysfunction on echocardiogram
  • previous stroke or TIA
  • moderate to severe LV dysfunction
  • history of heart failure
  • history of diabetes
  • age



    A Cox proportional hazards model was used to adjust for confounding factors.

    ?100% followed for mean 1.6 years
    Outcomes studied:
  • ischaemic stroke

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    ischaemic stroke 1.6 years 78/1066 7.3%
    (5.8% to 8.9%)    		 14
    (11 to 17)

    prognostic factor for
    ischaemic stroke     		time to outcome adjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    previous stroke or TIA mean 1.6 years 3.4
    (1.8 to 6.6)     		6
    (2 to 17)
    moderate to severe LV dysfunction mean 1.6 years 2.5
    (1.5 to 4.4)     		9
    (4 to 27)
    history of heart failure mean 1.6 years 1.7
    (1.1 to 2.7)     		20
    (8 to 140)
    history of diabetes mean 1.6 years 1.7
    (1.0 to 2.8)     		20
    (8 to infinity)
    age mean 1.6 years 1.5
    (1.1 to 1.9)     		27
    (15 to 140)

    Citation

    1. Atrial Fibrillation Investigators , et al: echocardiographic predictors of stroke in patients with atrial fibrillation: a prospective study of 1066 patients from 3 clinical trials. Archives of Internal Medicine 1998; 158 : 1316-1320
    Search Terms: ?
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient atrial fibrillation
    Intervention or Exposure age, diabetes, heart failure, LV function, previous stroke
    Outcome