18F-FDG PET/CT in left ventricular assist device infections: In-depth characterization and clinical implications

Abstract

BackgroundPrevious retrospective studies suggest a good diagnostic performance of 18F-FDG-PET/CT in left ventricular assist device (LVAD) infections. Our aim was to prospectively evaluate the role of PET/CT in the characterization and impact on clinical management of LVAD infections. Methods40 patients (58[53–62] years) with suspected LVAD infection and 5 controls (69[64–71] years) underwent 18F-FDG-PET/CT. Four LVAD components were evaluated: exit site and subcutaneous driveline (peripheral), pump pocket, and outflow graft. The location with maximal uptake was considered the presumed site of infection. Infection was confirmed by positive culture (exit site or blood) and/or surgical findings. ResultsVisual uptake was present in 40 patients (100%) in the infection group vs 4 (80%) control subjects. For each individual component, presence of uptake was more frequent in the infection than in the control group. The location of maximal uptake was most frequently the pump pocket (48%) in the infection group and the peripheral components (75%) in the control group. SUVmax was higher in the infection than in the control group: SUVmax (average all components):6.9[5.1-8.5] vs 3.8[3.7-4.3], p=0.002; SUVmax (location of maximal uptake):10.6±4.0 vs 5.4±1.9, p=0.01.Pump pocket infections were more frequent in patients with bacteremia than without bacteremia (79% vs 31%, p=0.011). Pseudomonas (32%) and methicillin-susceptible Staphylococcus aureus (29%) were the most frequent pathogens and were associated with pump pocket infections, while Staphylococcus epidermis (11%) was associated with peripheral infections. PET/CT affected the clinical management of 83% of patients with infection, resulting in surgical debridement (8%), pump exchange (13%), and upgrade in the transplant listing status (10%) leading to 8% of urgent transplants. Conclusions18F-FDG-PET/CT enables the diagnosis and characterization of the extent of LVAD infections, which can significantly affect the clinical management of these patients.