Common diagnostic flowcharts in infective endocarditis

The presentation of infective endocarditis (IE) has changed over time and its diagnosis remains difficult since it relies on the conjunction of a number of criteria which have their own limitations. The Duke classification allows for a standardized approach and is now recognized as the reference method for the diagnosis of IE. The diagnostic value of the different criteria of the Duke classification can be improved by the use of transoesophageal echocardiography for the detection of endocardial involvement and the use of non-cardiac imaging for the detection of embolic events. The number of cases of IE without identified causative microorganism can be reduced due to serological analyses and broad-range polymerase chain reaction on explanted valves. Radionuclide imaging techniques are useful when the diagnosis of IE remains uncertain. [ ¹⁸F]FDG PET/CT can be used for the diagnosis of cardiac infection and for the detection of embolic events or metastatic infection, keeping in mind the possibility of false positive diagnosis due to its high sensitivity. Radiolabelled-leukocytes scintigraphy is more specific than [¹⁸F]FDG PET/CT and can differentiate between septic and sterile vegetations. Diagnostic flowcharts are proposed to combine the Duke classification and recent imaging techniques for the diagnostic workup of IE.