Assessment of infective endocarditis
Baddour, 2015Bayer, 2021Eleyan, 2021 Habib, 2019Habib, 2015Saraste, 2019Satriano, 2020
The diagnosis of infective endocarditis should be made using the modified Duke diagnostic criteria1Li, 2000, although these criteria have lower sensitivity in infections related to prosthetic valves, cardiac devices, endocarditis on the right side of the heart and culture-negative endocarditisChambers, 2020Wang, 2018.
In patients with suspected infective endocarditis, take blood cultures before starting antibiotic therapy. Approach to blood cultures for patients with suspected infective endocarditis outlines the approach to blood cultures for assessment of endocarditis.
- Take blood cultures before starting antibiotic therapy.
- Take at least 3 sets of blood for culture because the pathogen is identified in about 90% of cases when 3 sets are taken. Take 2 sets immediately and take the third set at least 1 hour later.
- In patients with sepsis or septic shock, the priority is to start appropriate empirical antibiotic therapy as soon as possible, so all 3 sets of blood cultures should ideally be taken over a short time period before starting antibiotics.
- Blood cultures should ideally be taken from 3 separate venipuncture sites to avoid any misdiagnosis, in case one set is accidentally contaminated at the time of collection.
- Optimising blood sample volume is important for diagnostic accuracy, whereas timing in relation to onset of fever is less important.
- In children, ideally take 3 sets of blood for culture but this may be difficult to achieve – optimise the volume of blood from 1 to 2 sets.
- For more information on factors that determine the accuracy of blood cultures, see Principles of obtaining blood for culture.
Arrange an echocardiogram for patients with suspected infective endocarditis. Transoesophageal echocardiogram (TOE) is significantly more sensitive in the diagnosis of infective endocarditis than transthoracic echocardiogram (TTE), due to poor visualisation of heart valves and device leads by TTE. In particular, TOE is more sensitive than TTE for prosthetic valve and cardiac implantable electronic device–associated endocarditis. If a TTE is negative in a patient with suspected prosthetic valve and cardiac implantable electronic device–associated endocarditis, arrange a TOE if possiblePhilip, 2020.
The spread of infection to other organs and the progression of cardiac infection are common and should be particularly considered in patients who fail to improve or deteriorate on antibiotic therapy.
The role of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) in the diagnosis of infective endocarditis is yet to be accurately definedAnton-Vazquez, 2022Sag, 2022.