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Prosthetic Valve Endocarditis Diagnosed by 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

  • Shigeo Godo
    Correspondence
    Correspondence: Address to Shigeo Godo, MD, PhD, Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
    Affiliations
    Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan

    Department of Emergency and Critical Care Medicine, Tohoku University Hospital, Sendai, Japan
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  • Shigeki Kushimoto
    Affiliations
    Division of Emergency and Critical Care Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan

    Department of Emergency and Critical Care Medicine, Tohoku University Hospital, Sendai, Japan
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      A 74-year-old man with a history of prosthetic aortic valve replacement 4 years before presentation was evaluated for a fever since the previous day. Although multiple blood cultures were positive for penicillin-susceptible Streptococcus gordonii, an oral viridans streptococcus vegetation was not detected by echocardiography, and the modified Duke criteria for infective endocarditis were not met. Despite treatment with penicillin G (18 million units daily) for 2 weeks after negative blood cultures, 4 days after the last dose blood cultures turned positive for the identical organism. Results of repeated echocardiography and physical examinations were unremarkable. Laboratory results showed a mild increase in erythrocyte sedimentation rate and a positive rheumatoid factor, which were suggestive of, but still inconclusive for, the diagnosis of infective endocarditis. 18F-fluorodeoxyglucose positron emission tomography/computed tomography demonstrated a focal hot spot of fluorodeoxyglucose uptake around the prosthetic valve (Figure), a new major criterion for the diagnosis of prosthetic valve endocarditis in the latest guidelines.
      • Habib G.
      • Lancellotti P.
      • Antunes M.J.
      • et al.
      2015 ESC guidelines for the management of infective endocarditis: the Task Force for the Management of Infective Endocarditis of the European Society of Cardiology (ESC) Endorsed by: European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Nuclear Medicine (EANM).
      We diagnosed prosthetic valve endocarditis, which was cured using a higher dose of penicillin G (24 million units daily) for 6 weeks following negative blood cultures without any complications.
      Figure thumbnail gr1
      FigureAbnormal fluorodeoxyglucose uptake around the site of aortic prosthetic valve (arrow).
      Although echocardiography and blood cultures are central to the diagnosis and management of patients with infective endocarditis,
      • Barton T.L.
      • Mottram P.M.
      • Stuart R.L.
      • Cameron J.D.
      • Moir S.
      Transthoracic echocardiography is still useful in the initial evaluation of patients with suspected infective endocarditis: evaluation of a large cohort at a tertiary referral center.
      the modified Duke criteria are inconclusive in more than 20% of patients with suspected prosthetic valve endocarditis.
      • Gomes A.
      • Glaudemans A.
      • Touw D.J.
      • et al.
      Diagnostic value of imaging in infective endocarditis: a systematic review.
      18F-fluorodeoxyglucose positron emission tomography/computed tomography is useful for the diagnosis of infective endocarditis in patients with prosthetic valves, especially when the conventional modified Duke criteria are not met despite a high clinical suspicion of the disease.
      • Swart L.E.
      • Gomes A.
      • Scholtens A.M.
      • et al.
      Improving the diagnostic performance of 18F-FDG PET/CT in prosthetic heart valve endocarditis.

      References

        • Habib G.
        • Lancellotti P.
        • Antunes M.J.
        • et al.
        2015 ESC guidelines for the management of infective endocarditis: the Task Force for the Management of Infective Endocarditis of the European Society of Cardiology (ESC) Endorsed by: European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Nuclear Medicine (EANM).
        Eur Heart J. 2015; 36: 3075-3128
        • Barton T.L.
        • Mottram P.M.
        • Stuart R.L.
        • Cameron J.D.
        • Moir S.
        Transthoracic echocardiography is still useful in the initial evaluation of patients with suspected infective endocarditis: evaluation of a large cohort at a tertiary referral center.
        Mayo Clin Proc. 2014; 89: 799-805
        • Gomes A.
        • Glaudemans A.
        • Touw D.J.
        • et al.
        Diagnostic value of imaging in infective endocarditis: a systematic review.
        Lancet Infect Dis. 2017; 17: e1-e14
        • Swart L.E.
        • Gomes A.
        • Scholtens A.M.
        • et al.
        Improving the diagnostic performance of 18F-FDG PET/CT in prosthetic heart valve endocarditis.
        Circulation. 2018; 138: 1412-1427