Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.