Diagnosing infections related to left ventricular assist devices (LVADs) is challenging due to poor accessibility and imaging artifacts, particularly when central components are involved. We investigated whether fluorine-18 fluorodeoxyglucose (18FFDG) positron emission tomography/computed tomography (PET/CT) improves the diagnosis of bloodstream infection (BSI) compared with clinical parameters alone. Sixty-one patients with suspected LVAD infection underwent PET/CT between 2016 and 2022. Fluorodeoxyglucose uptake at the LVAD exit site, driveline, inflow/outflow cannulas, and pump according to Deauville score (DS) and lymphadenopathy were assessed. C-reactive protein (CRP), body temperature, white blood cell count (WBC), and bloodstream infection (BSI) (positive blood cultures obtained within ±7 days) were documented. Overall, 52% of patients were BSI-positive; clinical parameters were not consistently correlated with DS. Sensitivity for detecting BSI was highest for CRP greater than 0.5 mg/dl (69%, 95% confidence interval CI: 50-84) and specificity for WBC (75%, 56-90). Positron emission tomography/computed tomography-based DS greater than or equal to 4 of peripheral components had less than 50% sensitivity and only modest specificity. Diagnostic performance was better for central components with the highest sensitivities for pump and outflow cannula (79%, 41-95; 77%, 56-91) and highest specificity for inflow cannula (85%, 55-98) in conjunction with positive lymphadenopathy (96%, 77-100). Combined with lymphadenopathy, PET/CT-based DS of central LVAD components outperforms standard clinical parameters in detecting LVAD-related BSI, thereby supporting an individualized therapeutic approach.
Metzger et al. (Fri,) studied this question.