Diagnostic value of FDG PET/CT imaging in patients with surgically managed infective endocarditis: results of a retrospective analysis at a tertiary center

Abstract

Background We assessed the diagnostic value of FDG PET/CT in a real-world cohort of patients with surgically managed infective endocarditis (IE). Methods We performed a retrospective analysis of all patients hospitalized in a tertiary IE referral medical center from January 2014 to October 2018 fulfilling the following criteria: ICD-10 code for IE and OPS code for both, heart surgery and FDG PET/CT. Results Final analysis included 29 patients, whereof 28 patients had surgically proven IE. FDG PET/CT scan was true-positive in 15 patients (sensitivity (SEN) 56%) and false-negative in 12 patients. Combination of Duke criteria (DC) with FDG PET/CT scan resulted in gain of SEN for all patients with confirmed IE (SEN of DC 79% vs SEN of combination DC and FDG PET/CT 89%), driven by a relevant gain in PVE patients only (SEN of DC 78% vs SEN of combination DC and FDG PET/CT 94%). Interestingly, higher prosthesis age was observed in patients with false-negative scans. Conclusions We found a SEN of 56% for FDG PET/CT in a real-world cohort of patients with surgically proven IE which was associated with a 16% gain of IE diagnosis in patients with PVE when combined with DC.

Contemporary Review of Multi-Modality Cardiac Imaging Evaluation of Infective Endocarditis

“…More recent trials show higher sensitivity and specificity than older ones. It has comparable performance in both biological and mechanical prosthetic valves [ 15 , 17 , 59 , 60 , 61 , 62 , 63 ]. It is especially useful when prosthetic valve-related artefacts impair assessment via TTE and TEE [ 64 , 65 ].…”

“…It is especially useful when prosthetic valve-related artefacts impair assessment via TTE and TEE [ 64 , 65 ]. It is also useful in the setting of culture-negative IE with fastidious organisms [ 44 , 57 , 59 , 60 , 61 , 62 , 63 ]. From a prognostic standpoint, positive FDG valvular uptake is associated with worse outcomes (death, hospitalizations, IE recurrence, acute heart failure, new embolic event) [ 66 ].…”

Molecular Imaging of Valvular Diseases and Cardiac Device Infection

“…However, another study showed that the improved sensitivity afforded by the addition of 18 F-FDG PET to modified Duke's criteria when compared against surgical diagnosis was only apparent for patients with prosthetic valve disease. 48 Hence, the absence of 18 F-FDG uptake in native valve endocarditis cannot reliably exclude infection. Several hypothetical explanations for the higher number of false-negative scans in native valve endocarditis compared to prosthetic valve endocarditis have been proposed, including potentially smaller vegetations that lack involvement of paravalvular structures, better response to initial antibiotic treatment, and differences in neutrophil content and fibrosis resulting in less inflammation.…”

Infective Endocarditis: Predictive Factors for Diagnosis and Mortality in Surgically Treated Patients

“…These valves regularly deflect the echo beam leading to reduced sensitivity of echocardiography for the detection of IE. F-18-FDG PET/CT is known to have a high sensitivity and specificity, which may vary within patient characteristics and is especially useful in patients whose prosthetic valves had been implanted >3 months ago [7,12,32,33].…”

“…These have an overall sensitivity of 80-90%, which is significantly lower in specific cases [10,11]. Especially in patients with prosthetic valves, the use of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG-PET/CT) may be helpful [12]. The valve vegetation is the nidus of IE and consequently serves as the main target for preoperative imaging and intraoperative diagnosis.…”