Atrial fibrillation: increased the risk of peripheral thromboembolism

Clinical bottom line (level 2b)

  1. Around one in fifty patients with atrial fibrillation diagnosed in hospital went onto have a peripheral thromboembolism.
  2. The risk was increased with
    • younger age at onset
    • peripheral atherosclerosis
Frost et al: Archives of Internal Medicine 2001; 161 : 272-276
Expires November 2003

The study

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

Setting: half of the population selected at random, Denmark 1980 to 1993

29862 patients (aged 50 to 89, 50% male) newly diagnosed in hospital with atrial fibrillation

Excluded if
  • died within 1 month of onset of AF
  • diagnosed in outpatient clinic
  • history of previous thromboembolism
  • history of AF or peripheral thromboembolism before 1979


    Factors studied:
  • age at onset, duration of AF, associated diseases, sex





    100% followed for until December 1993
    Outcomes studied:
  • peripheral arterial thromboembolism

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)    		 NNF
    (95% CI)
    peripheral arterial thromboembolism 10 years 621/29862 2.1%
    (1.9% to 2.2%)    		 48
    (45 to 52)

    • Crude RR compared with the general population:
      • men: 4.0 (95% CI: 3.5 to 4.6)
      • women: 5.7 (95% CI: 5.1 to 6.3)
    • Thromboembolism was more likely with
      • a younger age at onset
      • peripheral atherosclerosis
      • diabetes in men
      • hypertension in women
      • congestive heart failure in women

    Comments

    1. Distribution of thromboembolic events:
      • upper and lower extremities: 61%
      • mesenteric arteries: 29%
      • pelvic arteries: 9%
      • aorta: 7%
      • renal arteries: 2%

    Citation

    1. Frost L, Engholm G, Johnsen S, et al: incident thromboembolism in the aorta and the renal, mesenteric, pelvic and extremity arteries after discharge from hospital with a diagnosis of atrial fibrillation. Archives of Internal Medicine 2001; 161 : 272-276
    Search Terms: from ACP Journal Club other articles noted
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient atrial fibrillation
    Intervention or Exposure other diseases, age, sex, duration of AF
    Outcome thromboembolism
    		•