In patients with prosthetic valve endocarditis (PVE) and pathological valvular FDG uptake on the initial FDG-PET and not referred to valve replacement at the acute phase, the study will assess whether FDG-PET is able to identify those at increased risk of PVE relapse.

In patients medically treated for prosthetic valve infection (PVE), identification of persistent infection or of cure could be very useful to 1/ patients referral to high-risk surgery, 2/ initiation of suppressive antibiotic therapy, or 3/ simplify the follow-up in other patients. The hypothesis is that FDG-PET could thus identify patients at increased risk of recurrence in case of persistent pathological uptake In patients with prosthetic endocarditis and pathological valvular FDG uptake on the initial FDG-PET and not referred to valve replacement at the acute phase, the main objective is to estimate the proportion of those still showing pathological valvular FDG uptake after curative antibiotic treatment. The secondary objectives are 1/ to quantitatively compare the valvular FDG-PET uptake for each individual before and after treatment; 2/ to determine the proportion of those in whom extracardiac foci persist at the end of treatment ; 3/ to evaluate the association between valvular FDG uptake on PET at the end of treatment and PVE relapse at 6 months; 4/ to evaluate the diagnostic performance of an automatic analysis by artificial intelligence of FDG uptake before and after treatment to predict PVE relapse at 6 months.

This is a single-center prospective cohort study. The population is composed of 50 adults with definite PVE according to the ESC 2015 classification, not operated in the acute phase and with pathological FDG-PET at the beginning of curative antibiotic treatment.

A change in practices regarding the duration of antibiotic therapy and the use of valve replacement surgery and its potential complications would benefit patients and reduce the overall cost related to valve prosthesis infection to the healthcare system."

"Inclusion criteria:

• Patient aged 18 or over;
• Have a prosthetic valve implanted surgically or by catheter for at least 3 months;
• Presenting a definite IE on a prosthetic valve (ESC definition in force);
• Having benefited from an FDG-PET examination for diagnostic purposes as part of the treatment revealing pathological hyperuptake at the level of the prosthetic valve AND carried out <15 days after the start of antibiotic therapy for infective endocarditis;
• Absence of cardiac surgical intervention performed for the current episode of AE or planned before the end-of-treatment FDG-PET

Exclusion criteria:

• Patient under legal protection, guardianship or curators;
• Pregnancy, breastfeeding;
• Patient not affiliated to a health insurance scheme or not a beneficiary of a social security scheme;
• Simultaneous participation in a study on FDG-PET;
• Absence of informed consent signed by the patient."