Diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in prosthetic pulmonary valve infective endocarditis

Background Pulmonary prosthetic valve and conduit infective endocarditis (PPVE) is a major issue in the growing congenital heart disease (CHD) population. Diagnosis is challenging and usual imaging tools are not always efficient nor validated in this specific population. Particularly, the diagnostic yield of 18F-fluorodeoxyglucose (18F-FDG) Positron Emission Tomography (PET)/Computed Tomography (CT) remains poorly studied in PPVE. Aims The Aim of this study was to assess the diagnostic performances of 18F-FDG PET/CT in CHD patients with PPVE suspicion. Methods A retrospective multicenter study was conducted in 8 French tertiary centers. Children and adult CHD patients who underwent a 18F-FDG PET/CT in the setting of PPVE suspicion between January 2010 and May 2020 were included. The cases are initially classified as definite, possible or rejected PPVE regarding the modified Duke criteria (DC) and finally by the Endocarditis Team consensus. The result of 18F-FDG PET/CT had been compared to final diagnosis consensus used as gold-standard in our study. Results Sixty-six cases of PPVE suspicion involving 59 patients (median age 23, 73% male) were included. Sensitivity, specificity, positive predictive value and negative predictive value of 18F-FDG PET/CT in PPVE suspicion were respectively: 79.1% (68.4–91.4), 72.7% (60.4–85.0), 91.9% (79.6–100) and 47.1% (34.8–59.4). 18F-FDG PET/CT findings would help to rightly reclassify 43% of possible PPVE to definite PPVE. Conclusion Using 18F-FDG PET/CT improves the diagnostic accuracy of the Duke Criteria in CHD patients with suspected PPVE. Its high positive predictive value could be helpful in routine to shorten diagnosis and treatment delays and improve clinical outcomes.