Contribution of ¹⁸F-FDG PET/CT on non-operated prosthetic valve infective endocarditis follow-up

Introduction. - Prosthetic valve endocarditis is a diagnostic and therapeutic challenge; ¹⁸F-FDG PET/CT has seen increasing use and has been incorporated in the latest ESC endocarditis guidelines. Follow-up by PET/CT has never been studied. The aim was to study the use of PET/CT to help predicting recurrences after full antibiotic treatment. Methods. - From January 2011 to April 2016, all patients presenting with definite or possible prosthetic valve endocarditis were included and had a PET/CT after admission. After discharge, non-operated patients had a second PET/CT from 6 to 10 weeks after the end of intravenous antibiotic treatment, in addition to clinical and echocardiographic follow-up. Results. - Among 276 patients with prosthetic valve admitted for suspicion of infective endocarditis, 43 of them with an abnormal prosthetic uptake on the first PET/CT had a second PET/CT within a mean period of 67.3 days after the end of intravenous antibiotic treatment. The mean follow-up was 414 days. Five recurrences occurred among the 34 patients with persistent abnormal prosthetic uptake on second PET/CT, there was no recurrence among the nine patients who had no more abnormal prosthetic uptake. Conclusion. - This is the first study to evaluate the potential benefits of PET/CT for medically treated PVE follow-up. All recurrences occurred among patients with persistent abnormal prosthetic uptake on second PET/CT. An unexpected finding was the potential of bone-marrow and splenic uptake evolution, which is underused in IE and showed an interesting potential in the prognosis of these patients. (authors)