Risk factors for stroke in patients with nonrheumatic atrial fibrillation: A case-control study

https://doi.org/10.1016/0002-9343(91)90008-LGet rights and content

Abstract

purpose: Randomized controlled trials have demonstrated that anticoagulant therapy is very effective at preventing stroke among patients with nonrheumatic atrial fibrillation. However, these trials have reported too few strokes for powerful risk factor analysis. Observational studies may provide additional information. The purpose of this study was to identify risk factors in a larger number of patients with stroke and nonrheumatic atrial fibrillation, using case-control methodology.

patients and methods: We identified all patients discharged from one hospital over an 8year period who met our case definition of nonrheumatic atrial fibrillation and ischemic stroke (n = 134), and compared them with contemporaneous control subjects who were discharged with non-rheumatic atrial fibrillation without stroke (n = 131).

results: Cases and controls were similar in terms of duration of atrial fibrillation; proportion with paroxysmal atrial fibrillation; percentage with a past medical history of angina, myocardial infarction, congestive heart failure, diabetes, or smoking; and mean left atrial size. In contrast, cases were significantly older than controls (78.5 versus 74.8 years, p = 0.002) and more likely to have a history of hypertension (55% versus 38%, p = 0.0093). The relative odds for stroke was 1.91 for patients with hypertension, 1.73 for patients older than 75 years, and 3.26 for patients with both factors.

conclusion: Our analysis suggests that age and hypertension should be considered when deciding upon long-term anticoagulant therapy to prevent stroke in patients with nonrheumatic atrial fibrillation.

References (34)

  • PA Wolf et al.

    Duration of atrial fibrillation and imminence of stroke: the Framingham Study

    Stroke

    (1983)
  • PA Wolf et al.

    Atrial fibrillation: a major contributor to stroke in the elderly: the Framingham Study

    Arch Intern Med

    (1987)
  • Stroke Prevention in Atrial Fibrillation Study Group Investigators

    Preliminary report of the Stroke Prevention in Atrial Fibrillation Study

    N Engl J Med

    (1990)
  • The Boston Area Anticoagulation Trial in Atrial Fibrillation Investigators

    The effect of low-dose warfarin on the risk of stroke in patients with non-rheumatic atrial fibrillation

    N Engl J Med

    (1990)
  • AE Weyman

    Cross-sectional echocardiography

    (1982)
  • Crunch Statistical Package

    (1987)
  • OS Miettinen

    Estimability and estimation in case-referent studies

    Am J Epidemiol

    (1976)
  • Cited by (0)

    Partial support for this study was provided by the Harvard General Medicine Fellowship (Dr. Moulton), the Charles Dana Fellowship for Harvard Medical School (Dr. Haas), and the Henry J. Kaiser Family Foundation via a Faculty Scholar Award (Dr. Singer).

    View full text