Role of [18F]FDG PET/CT in patients with suspected ventricular assist device infection

Objectives Ventricular assist devices (VAD) are used in patients with heart failure either as bridge therapy to cardiac transplantation or as destination therapy. The aim of this study is to evaluate the usefulness and diagnostic capability of [18F]FDG PET/CT in patients carrying VADs with suspected underlying infectious processes. Material and methods Retrospective descriptive study of patients (p) carrying VAD, with performance of [18F]FDG PET/CT for suspected infection between July 2018 and January 2023. Demographic data, baseline pathology, VA purpose and PET/CT findings were studied. Results 11p (5 female, 5 male, 1 transgender female) with a mean age of 55.4 years [31-76], affected by dilated cardiomyopathy (8 ischaemic, 2 toxic secondary to chemotherapeutic treatment, 1 idiopathic) were analysed. 7p were VAD carriers as bridging therapy and 4p as destination. The reasons for requesting PET/CT were in 10p clinical suspicion of device infection and in 1p suspicion of interstitial nephritis. 5p presented PET/CT suggestive of infection (4 on driveline entry and subcutaneous tract; 1 on ventricular device and mediastinal cannulae). Microbiological analysis was performed in all of them and was positive in only 3p. Despite this, all 5p received antibiotic treatment with beta-lactams (4p with resolution of the infectious condition and 1p requiring cardiac transplantation). 1p presented a discrete increase in metabolism at the level of the subcutaneous driveline tract attributable to an inflammatory process. 5p showed no findings suggestive of infection by PET/CT and the final diagnosis was unrelated to the VAD (2p without infection and 3p with infection in locations other than the VAD). The median SUVmax of patients with extrathoracic infection (driveline entry and subcutaneous tract) was 2.5 g/ml vs. 1.36 g/ml in relation to the rest of the patients without infection. The median SUVmax of patients with intrathoracic infection was 4.99 g/ml vs. 3.6 g/ml for the rest of the patients without infection. Conclusion 18F]FDG PET/CT has been able to detect in our sample, in a non-invasive way, infection related to ventricular assist devices, presenting higher diagnostic yield and a high negative predictive value with respect to microbiological analysis.