18F-FDG-PET/CT Leads to Improved Source Control of Extracardiac Complications in Infective Endocarditis

Background: Extracardiac complications (ECCs) contribute to morbidity and mortality in patients with infective endocarditis (IE). Current guidelines recommend ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) as a screening tool for ECCs. This study assessed the clinical impact of ECCs detected by ¹⁸F-FDG-PET/CT compared to conventional diagnostics in patients with suspected IE. Methods: Patients with possible or definite IE (European Society of Cardiology 2015 criteria) were prospectively enrolled in the Amsterdam UMC endocarditis team registry from October 2016 till March 2021. The primary outcome, the number of source control interventions (SCIs), was analyzed using Cox regression analyses extended for recurrent events, with ¹⁸F-FDG-PET/CT as a time-dependent covariate. Secondary outcomes included the crude number needed to scan to perform 1 additional SCI, predictors associated with SCIs, and 90-day all-cause mortality adjusted for both immortal time bias and confounders. Results: We included 252 patients, 152 in the ¹⁸F-FDG-PET/CT group and 100 in the control group. In the control group, 18 SCIs were performed. In the ¹⁸F-FDG-PET/CT group, 57 SCIs were performed, of which 21 were prompted by ¹⁸F-FDG-PET/CT findings. The crude number needed to scan leading to 1 additional SCI was 8 (95% confidence interval [CI], 6–15). ¹⁸F-FDG-PET/CT was associated with the number of SCIs, with an adjusted hazard ratio (aHR) of 2.96 (95% CI, 1.36–6.44). No variables were significantly associated with ¹⁸F-FDG-PET/CT-related SCIs. No differences were found in mortality between the control and PET/CT group (aHR, 0.69 [95% CI, .40–1.20]). Conclusions: The use of ¹⁸F-FDG-PET/CT among patients with suspected IE leads to increased SCIs for ECCs.