Prospective evaluation of the Moleculight i:X™ in the early detection of driveline infections.

Abstract

Objectives: Driveline infection (DLI) is a common complication in patients with left ventricular assist devices. This complication can seriously undermine quality of life while on left ventricular assist devices. Current diagnosis of a DLI in the outpatient setting is based on clinical examination and later bacteria isolation. The Moleculight i:XTM is a handheld fluorescence imaging device capable to visualize bacterial colonization in real-time. We here evaluated the performance of the Moleculight i:XTM for diagnosis of DLIs as this device may have the potential advantage to rapidly identify infection and therefore promptly influence therapy.

Methods: A total of 107 examinations in patients with suspected DLIs were prospectively included in this study. All examinations took place in the outpatient setting. In addition to the standard treatment, Moleculight fluorescence images were captured and swabs were taken at the area of maximal luminosity. Wounds and pictures were reviewed and classified as positive or negative by a wound specialist and two heart surgeons independently from microbiological results.

Results: The Moleculight i:XTM showed positive results (red fluorescence) in 19 cases (17.76%), whereas microbiological examination was positive for microorganisms in 74 cases (69.16%). The most common bacteria was Staphylococcus aureus. The findings resulted in a sensitivity of 13.51% and a specificity of 72.73%. The positive predictive value was 52.63% and the negative predictive value was 27.27%. Sub-analyses of different wound dressings or previous antibiotic treatment did not show any relevant difference.

Conclusions: The results of the Moleculight i:X show a low sensitivity and specificity when being used to detect DLIs in the outpatient setting. Clinical examination and swabs should remain the gold standard despite the delay for bacteria isolation and consequent antibiotic treatment. Sensitivity and specificity of the Moleculight i:X in open wounds after surgical revision of the driveline remain to be clarified.