Added value of semi-quantitative analysis of [18F]FDG PET/CT for the diagnosis of device-related infections in patients with a left ventricular assist device.

AIMS: Left ventricular assist devices (LVADs) improve quality of life and survival in patients with advanced heart failure, but device-related infections (DRIs) remain cumbersome. We evaluated the diagnostic capability of [18F]FDG PET/CT, factors affecting its accuracy, and the additive value of semi-quantitative analysis for the diagnosis of DRI. METHODS AND RESULTS: LVAD recipients undergoing [18F]FDG PET/CT between 2012 and 2020 for suspected DRI were retrospectively included. [18F]FDG PET/CT was performed and evaluated in accordance with EANM guidelines. The final diagnosis of DRI, based on multidisciplinary consensus and findings during surgery, whenever performed, was used as the reference for diagnosis. 41 patients were evaluated for 59 episodes of suspected DRI. The clinical evaluation established driveline infection in 32 (55%) episodes, central device infection in 6 (11%), and combined infection in 2 (4%). Visual analysis of [18F]FDG PET/CT achieved a sensitivity and specificity for driveline infections of 0.79 and 0.71, respectively, whereas semi-quantitative analysis achieved a sensitivity and specificity of 0.94 and 0.83, respectively. For central device component infection, visual analysis of [18F]FDG PET/CT achieved a sensitivity and specificity of 0.75 and 0.60, respectively. Semi-quantitative analysis using SUVratio achieved a sensitivity and specificity of 1.0 and 0.8, respectively. The increase of specificity for central component infection was statistically significant (P = 0.05). CONCLUSIONS: [18F]FDG PET/CT reliably predicts the presence of DRI in LVAD recipients. Semi-quantitative analysis may increase the specificity of [18F]FDG PET/CT for the analysis of central device component infection and should be considered in equivocal cases after visual analysis.

18F-FDG/PET-CT imaging findings after sternotomy.

BACKGROUND: The clinical diagnosis of deep sternal wound infection (DSWI) is supported by imaging findings including 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT). To avoid misinterpretation due to normal post-surgery inflammation we assessed normal imaging findings in non-infected patients after sternotomy. METHODS: This is a prospective cohort study including non-infectious patients with sternotomy. All patients underwent 18F-FDG-PET/CT at either 5 weeks (group 1), 12 weeks (group 2) or 52 weeks (group 3) post-surgery. 18F-FDG uptake was scored visually in five categories and assessed quantitatively. RESULTS: A total of 44 patients were included. Sternal mean SUVmax was 7.34 (± 1.86), 5.22 (± 2.55) and 3.20 (± 1.80) in group 1, 2 and 3, respectively (p < 0.01). Sternal mean SUVmean was 3.84 (± 1.00), 2.69 (± 1.32) and 1.71 (± 0.98) in group 1, 2 and 3 (p < 0.01). All patients in group 1 had elevated uptake whereas group 2 and 3 showed 2/15 (13%) and 11/20 (55%) patients respectively with no elevated uptake. Group 3 still showed an elevated uptake pattern in in 9/20 (45%) and in 3/9 (33%) with a high-grade diffuse uptake pattern. CONCLUSION: This study shows significant lower sternal 18F-FDG at 55 weeks compared to 5 weeks post-sternotomy however elevated uptake patterns may persist.

Screening for coronary artery disease in early surgical treatment of acute aortic valve infective endocarditis.

OBJECTIVES: In patients with unknown coronary status undergoing surgery for acute infective endocarditis (IE), the need to screen for coronary artery disease (CAD) and the risk of embolization during invasive coronary angiography (ICA) are debated. Coronary computed tomography angiography (CCTA) is a non-invasive alternative in these patients. We aimed to evaluate the safety and feasibility of ICA and CCTA to diagnose CAD, and the necessity to treat CAD to prevent CAD-related postoperative complications. METHODS: In this single-centre retrospective cohort study, all patients with acute aortic IE between 2009 and 2019 undergoing surgery were selected. Outcomes were any clinically evident embolization after preoperative ICA, in-hospital mortality, perioperative myocardial infarction or unplanned revascularization and postoperative renal function. RESULTS: Of the 159 included patients, CAD status was already known in 14. No preoperative diagnostics for CAD was done in 46/145, a CCTA was performed in 54/145 patients and an ICA in 52/145 patients. Significant CAD was found after CCTA in 22% and after ICA in 21% of patients. In 1 of the 52 (2%) patients undergoing preoperative ICA, a cerebral embolism occurred. The rate of perioperative myocardial infarction or unplanned revascularization in patients not screened for CAD was 2% (1 out of 46 patients). CONCLUSIONS: Although the risk of embolism after preoperative ICA is low, it should be carefully weighed against the estimated risk of CAD-related perioperative complications. CCTA can serve as a gatekeeper for ICA in most patients with acute aortic IE.