The value of fluorine-18 deoxyglucose positron emission tomography scans in patients with ventricular assist device specific infections†

Background: Infections are major complications in patients with ventricular assist devices (VAD). Positron emission tomography with deoxyglucose marked by fluorine-18 ( 18 F-FDG PET/CT) is a diagnostic tool to scan for tissue with high metabolism as present in infections. The specificity of 18 F-FDG PET/CT to discriminate between infection and an aseptic reaction of the implanted device is not defined and its evaluation is the aim of this retrospective analysis.

Methods: Until September 2015 a total of 100 patients underwent VAD implantations in our institution. Twenty-one patients (mean age 53.7 ± 14.3 years) had 29 PET-CT examinations for a suspected infection. All radiology reports were compared to clinical and intraoperative parameters. Infections were reported according to the guidelines of the International Society of Heart and Lung Transplantation. Follow-up was 222 days (range 107-484 days) after PET-CT scans and was complete in all patients.

Results: In 7 patients PET-CT scan ruled out any VAD associated infection. Sixteen patients had a VAD specific infection. Two patients had false negative PET-CT scan results. The sensitivity of VAD-specific infections was 87.5%, the specificity 100%, the positive predictive value was 100% and the negative predictive value 86.7%. Seven patients had more than one PET-CT scans at different time points.

Conclusions: PET-CT scan findings showed a high specificity and positive predictive value for VAD-specific infections. Therefore, it may have the potential to guide the clinician in handling patients with infectious complications after VAD implantation.