Value of ¹⁸F-FDG pet/CT for prognostic assessment in patients with infective endocarditis

¹⁸F-FDG PET/CT is a valuable diagnostic tool in infective endocarditis (IE). However, the prognostic value is unclear. This study aims to evaluate the prognostic performance of ¹⁸F-FDG PET/CT in native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE).

We retrospectively included 76 patients treated for definite IE (NVE and PVE) that underwent ¹⁸F-FDG PET/CT between January 2016 and December 2018. Clinical, echocardiographic and ¹⁸F-FDG PET/CT (pathologic valvular ¹⁸F-FDG uptake, extracardiac complications (ECC)) data were collected. The primary endpoint was defined as mortality or recurrence of IE at a one-year follow-up.

Pathologic valvular ¹⁸F-FDG uptake was detected in 32 of 57 (56.1%) patients, 30% (9/30) in NVE and 85.2% (23/27) in PVE group. Atrial fibrillation (OR 3.90, 95% CI = 1.14-16.3), prior anticoagulation treatment (OR 6.37, 95% CI = 1.89-26.7), large vegetation (≥ 10 mm) (OR 4.05, 95% CI = 1.14-16.1), perivalvular complications (OR 7.22, 95% CI = 1.68-55.1) and abscess (OR 10.9, 95% CI = 1.84-283) were associated with positive PET/CT. Extracardiac complications were found in 27 of 76 (35.5%) patients, 42.9% (18/42) in the NVE and 26.5% (9/34) in the PVE group. Pathological valvular tracer uptake (HR 1.20, 95% CI = 0.43-3.37) or extracardiac complications (HR 0.58, 95% CI = 0.21-1.62) were not associated with the occurrence of the primary endpoint.

Our study could not demonstrate a prognostic value of ¹⁸F-FDG PET/CT in IE, but confirms high diagnostic performance, which may compromise prognostic significance by accelerated optimal treatment because of earlier diagnostic certainty.