Program Schedule

A Normal Transthoracic Echocardiogram can be Used to Rule Out Infective Endocarditis in Patients with Staphylococcus aureus Bacteremia

Session: Poster Abstract Session: Infective Endocarditits: Epidemiology, Diagnosis, and Management
Friday, October 10, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
  • TTE in SAB IDSA 2014 _Showler.pdf (483.7 kB)
  • Background: Staphylococcus aureus is a major cause of bacteremia and often leads to infective endocarditis (IE). Current guidelines recommend performing transesophageal echocardiography (TEE) in all patients or treating empirically with prolonged intravenous antibiotics.  Many physicians do not adhere to guidelines, and recent studies suggest that low-risk patients do not require TEE.  

    Methods: We retrospectively evaluated hospitalized patients with S. aureus bacteremia (SAB) from seven hospitals in Toronto, Ontario over a 3-year period.  In 536 patients who received a TTE within 28 days of bacteremia, we randomly divided the sample into development (n=268) and validation (n=268) cohorts. We derived criteria to rule out infective endocarditis based on multivariable logistic regression analysis in the development cohort, and applied these criteria to the validation cohort to determine criteria diagnostic properties.

    Results: In multivariable analysis, four criteria were useful to rule out infective endocarditis:  a normal TTE (p<0.001), non-community-acquired bacteremia (p=0.002), no intravenous drug use (p<0.001), and absence of high-risk cardiac conditions (p<0.001).  In the validation sample, failing any criteria had a 97% sensitivity, 52% specificity, 25% positive predictive value, and 99% negative predictive value for infective endocarditis.  The negative likelihood ratio was 0.05.

    Conclusion: A prediction model including normal TTE, non-community acquired bacteremia, no intravenous drug use, and absence of high-risk cardiac conditions is a useful tool to identify patients at low risk of infective endocarditis.  Risk stratification combined with TTE may be adequate to rule out IE in most patients with SAB.

    Adrienne Showler, MD1, Lisa Burry, PharmD2, Anthony Bai, BSc3, Daniel Ricciuto, MD4, Marilyn Steinberg, RN5, Tania Fernandes, PharmD6, Anna Chiu, PharmD6, Sumit Raybardhan, BSc.Phm MPH7, Eshan Ferndando, MD1, Chaim Bell, MD, PhD1 and Andrew Morris, MD, SM1, (1)University of Toronto, Toronto, ON, Canada, (2)Mount Sinai Hospital, Toronto, ON, Canada, (3)University of Ottawa, Ottawa, ON, Canada, (4)Lakeridge Hospital, Oshawa, ON, Canada, (5)Mount Sinai Hospital, 600 University Ave, Toronto, ON, Canada, (6)Trillium Health Center, Toronto, ON, Canada, (7)North York General Hospital, Toronto, ON, Canada


    A. Showler, None

    L. Burry, None

    A. Bai, None

    D. Ricciuto, None

    M. Steinberg, None

    T. Fernandes, None

    A. Chiu, None

    S. Raybardhan, None

    E. Ferndando, None

    C. Bell, None

    A. Morris, None

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