18F-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) has been shown to be useful for the diagnosis of infective endocarditis (IE), but its prognostic value remains unknown.

This study sought to assess the prognostic value of 18F-FDG PET/CT in prosthetic (PVE) and native valve endocarditis (NVE).

We prospectively studied 173 consecutive patients (109 PVE and 64 NVE) with definite IE who underwent an 18F-FDG PET/CT study and were follow-up for one year. Primary end-point was a composite of major cardiac events i.e. death, recurrence of IE, acute cardiac failure, non-scheduled hospitalization for cardiovascular reason, and new embolic event.

18F-FDG PET/CT was positive in 100 (58%) patients, 83% (n=90/109) in the PVE and 16% (n=10/64) in the NVE group. At a mean follow of 225days (199 to 251days), the primary end-point occurred in 94 (54%) patients, 63 (58%) in the PVE group and 31 (48%) in the NVE group. In the PVE group, positive 18F-FDG PET/CT was significantly associated with higher rate of primary end-point (OR=2.6, IC95%=1.04 to 6.6; P=0.04). Moderate to intense 18F-FDG valvular uptake was also associated with worse outcome (OR=2.1; IC95%=1.1 to 4.0; P=0.03) and to new embolic events, (OR=7.5; IC95%=1.24 to 45.2) P=0.03). In the NVE group, 18F-FDG PET/CT was not associated with occurrence of the primary end-point.

In addition to be an accurate diagnostic tool, 18F-FDG PET/CT is predictive of major cardiac events in PVE and of embolic events during the first year following IE episode.