The diagnosis of prosthetic valve endocarditis (PVE) remains challenging. In PVE cases, initial echocardiography is normal or inconclusive in almost 30% of cases, leading to a decreased diagnostic accuracy for the modified Duke criteria.

Aims: The investigators sought to determine the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for diagnosing PVE.

Methods: In two referral French centers (Timone Hospial, Marseille and Georges Pompidou European Hospital, Paris), the investigators plan to include consecutive patients suspected of having PVE. All of the patients will be subjected to clinical, microbiological, and echocardiographic evaluation. Cardiac PET/CT will be performed at admission and the data analysis will be based on visual interpretation and quantitative measurement of FDG uptake (SUVmax). The final diagnosis will be defined according to the clinical and/or pathological modified Duke criteria determined during a 3-month follow-up (gold standard).

Inclusion Criteria:

• unexplained persistent or recurrent fever >38°C;
• and/or unexplained increased serum C-reactive protein (CRP) level >10 mg/L; and/or positive blood cultures, independent of the echocardiographic analysis results;
• and/or positive serological testing for Coxiella burnetii, Bartonella spp., Mycoplasma pneumoniae, Legionella pneumophila, Aspergillus spp., or Tropheryma whipplei;
• and/or a mass or a new partial prosthetic valve dehiscence observed using echocardiography.

Exclusion Criteria:

• pregnancy,
• an inability to lie flat,
• a need for urgent cardiac surgery,
• hemodynamic instability,
• cardiac surgery <1 month ago,
• and a blood glucose level >1.8 g/L. Patients with a poor PET/CT image quality