18-Fluoro-2-deoxyglucose positron emission tomography-computed tomography: an additional tool in the diagnosis of prosthetic valve endocarditis

Objectives: To evaluate the role of 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG-PET-CT) in the diagnosis of infectious endocarditis (IE). Methods: We retrospectively examined 27 consecutive patients who were admitted to the Infectious Diseases Department of Tor Vergata University Hospital between 2009 and 2013 with a suspicion of IE. The final IE diagnosis was defined according to the modified Duke criteria, and the microbiological and diagnostic results were collected for each patient. Results: Twenty out of 27 patients had a suspected prosthetic valve endocarditis (PVE) and seven had a suspected native valve endocarditis (NVE). Twenty-five out of 27 patients (92%) had a confirmed diagnosis of IE (18/25 PVE and 7/25 NVE); 16 had a positive echocardiography evaluation and 16 had positive ¹⁸F-FDG-PET-CT findings. Echocardiography showed a higher sensitivity as a diagnostic tool for the detection of IE compared to ¹⁸F-FDG-PET-CT (80% vs. 55%). However, a greater number of PVE had positive ¹⁸F-FDG-PET-CT results compared to those with positive echocardiography findings (11/13 vs. 9/13), and overall 89% (16/18) of confirmed PVE resulted ¹⁸F-FDG-PET-CT positive. Analyzing only the cases who underwent transoesophageal echocardiography, ¹⁸F-FDG-PET-CT showed a sensitivity of 85% in PVE (vs. 69% for echocardiography and 77% for the Duke criteria). All seven patients with NVE had a positive echocardiography and negative ¹⁸F-FDG-PET-CT findings (p18F-FDG-PET-CT in these cases.