Infective endocarditis: transthoracic echocardiogram could diagnose but not exclude vegetations.

Clinical bottom line (level 1b)

  1. Roughly half of patients suspected to have infective endocarditis had vegetations or abscess cavities.
  2. Transthoracic echocardiography was as good as transoesophageal echocardiography at diagnosing vegetations
  3. A normal transthoracic echocardiogram could not safely exclude vegetations and further testing was required.
Irani et al: American Journal of Cardiology 1996; 78: 101-103
Expires July 2003

The study

Setting: university hospital, USA, 1991 to 1995

114 patients (aged range 17 to 89 years; mean 45, 65% male) suspected infective endocarditis

Excluded if
  • prosthetic heart valve
  • had only TTE



    • Independent blinded reference standard, applied in all patients from a non-consecutive appropriate spectrum.
    Reference standard:
    • transoesophageal echocardiography- presence or absence of vegetation or abscess
    Diagnostic test: transthoracic echocardiography in left lateral decubitus position
    • positive- presence of a vegetation or abscess cavity
    • non-diagnostic- presence of leaflet thickening, calcification, and/or more than trace regurgitation but no definite vegetation
    • negative- absence of any valvular abnormality

    The evidence

    pre-test probability of vegetation or abscess cavity: 45%, (95% CI: 36% to 53%)

    diagnostic test vegetation or abscess cavity no vegetation or abscess cavity LR
    (95% CI)    		 post-test probability
    positive TTE 41 0 100
    (17 to inf)     		100%
    non-diagnostic TTE 17 30 0.70
    (0.43 to 1.14)     		36%
    negative TTE 2 44 0.056
    (0.014 to 0.22)     		4%
    total 60 74

    • Patients underwent TEE a mean of 4 +/- 5 days after TTE. No change in clinical status occurred in the time interval between TTE and TEE.
    • Transoesophageal echo is a poor reference standard- patients with negative TEEs may still have vegetations.

    Citation

    1. Irani WN, et al: A negative transthoracic echocardiogram obviates the need for transesophageal echocardiography in patients suspected with native valve active endocarditis. American Journal of Cardiology 1996; 78: 101-103
    Search Terms: explode 'infective, endocarditis and echocardiography'
    Contributor: Sumit Dhingra, Carl Heneghan and Chris Ball, July 2000
    Reviewer:

    Clinical Question.
    Patient suspected endocarditis
    Intervention or Exposure transoesophageal echo, TEE, TOE
    Comparison transthoracic echo, TTE
    Outcome vegetations, abscesses