18F-fluorodeoxyglucose positron emission tomography/computed tomography for the diagnosis of native valve infective endocarditis: A prospective study.

BACKGROUND

18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) has recently been added as a major criterion in the European Society of Cardiology (ESC) 2015 infective endocarditis guidelines. PET/CT is currently used in patients with suspected prosthetic valve and cardiac device-related endocarditis. However, the value of the ESC classification and the clinical impact of PET findings are unknown in patients with native valve endocarditis (NVE).

AIMS: Our aims were: to assess the value of the ESC criteria (including PET/CT) in NVE; to determine the usefulness of PET/CT concerning embolic detection; and to describe a new PET/CT feature (diffuse splenic uptake).

METHODS

Between 2012 and 2017, 75 patients with suspected NVE were included prospectively, after exclusion of patients with uninterpretable or unfeasible PET/CT. Using gold standard expert consensus, 63 cases of infective endocarditis were confirmed and 12 were rejected.

RESULTS

Significant valvular uptake was observed in 11 of 63 patients with definite NVE and in no patients who had the diagnosis of infective endocarditis rejected (sensitivity 17.5%, specificity 100%). Among the 63 patients with NVE, a peripheral embolism or mycotic aneurysm was observed in 20 (31.7%) cases. Application of the ESC criteria increased Duke criteria sensitivity from 63.5% to 69.8% (P<0.001), without a change in specificity. Diffuse splenic uptake was observed in 39 (52.0%) patients, including 37 (58.7%) with a final diagnosis of NVE (specificity 83.3%).

CONCLUSIONS

18F-FDG PET/CT has poor sensitivity but high specificity in the diagnosis of NVE. The usefulness of 18F-FDG PET/CT is high for embolic detection. Diffuse splenic uptake represents a possible new diagnostic criterion for NVE.