Pulmonary embolism: ventilation-perfusion scanning was not affected by pre-existing heart-lung disease.

Clinical bottom line (level 1b)

  1. Ventilation-perfusion scans were as effective at diagnosing pulmonary embolism in patients with pre-existing heart or lung disease as in those without.
  2. More patients with pre-existing heart or lung disease had non-diagnostic scans (~ 40% v. 30%).
Stein et al: Chest 1991; 100 (3): 604-606
Expires October 2003

The study

Setting: five centres, Canada

891 patients (aged mean 55 years, 51% female) 365 patients with clinically suspected PE, and no previous heart or lung disease (aged ~ 50 years; 62% female). (No heart or lung disease if:
  • no history or evidence of valvular heart disease, coronary artery disease, myocardial infarction, "other heart disease" or no prior CCF
  • no asthma, COPD, interstitial lung disease, "other lung disease" and no acute pneumonia or acute respiratory distress syndrome on presentation
  • no previous PE)
526 patients with clinically suspected PE and previous heart or lung disease (aged ~ 60 years; 50% male).

Excluded if
  • aged <18



    • Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
    Reference standard:
    • pulmonary angiography or follow-up
    Diagnostic test: ventilation-perfusion scanning

    The evidence

    pre-test probability of pulmonary embolism with no disease: 32%, (95% CI: 27% to 37%)
    pre-test probability of pulmonary embolism with heart or lung disease: 27%, (95% CI: 23% to 30%)

    diagnostic test pulmonary embolism: no disease no pulmonary embolism LR
    (95% CI)    		 post-test probability
    high probability scan 50 4 27
    (10 to 72)     		93%
    intermediate 47 72 1.4
    (1.0 to 1.9)     		40%
    low 17 96 0.38
    (0.24 to 0.60)     		15%
    normal/ near normal 3 76 0.084
    (0.027 to 0.26)     		3.8%
    total 117 248


    diagnostic test pulmonary embolism: heart/ lung disease no pulmonary embolism LR
    (95% CI)    		 post-test probability
    high probability 55 11 14
    (7.4 to 26)     		83%
    intermediate 58 169 0.95
    (0.75 to 1.2)     		26%
    low 25 157 0.44
    (0.30 to 0.64)     		14%
    normal/ near normal 2 49 0.11
    (0.028 to 0.46)     		3.9%
    total 140 386

    • More patients with heart/lung disease had intermediate scans (227/526 (43%) v. 119/ 365 (33%); p < 0.01).

    Citation

    1. Stein PD, Coleman RE, Gottschalk A, et al: Diagnostic utility of ventilation/perfusion lung scans in acute pulmonary embolism is not diminished by pre-existing cardiac or pulmonary disease. Chest 1991; 100 (3): 604-606
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient suspected PE and with or without heart or lung disease
    Intervention or Exposure ventilation-perfusion scans
    Outcome diagnosis of PE