Preliminary Results of a New Treatment Strategy for Relapsed Left Ventricular Assist Device-Specific Infections

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

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.

Risk factors, diagnostic methods and treatment of infection in adult patients undergoing left ventricular assist device implantation: A scoping review

BACKGROUND

Evidence on infection risk factors is scarce, and precise localization of the site of infection and its treatment remain clinically challenging.

OBJECTIVES

This study aimed to map the recommendations for adult patients undergoing left ventricular assist device implantation.

DESIGN

This is a scoping review, registered in the Open Science Framework under DOI10.17605/OSF.IO/Q76B3(https://osf.io/q76b3/).

METHOD

This is a scoping review limited to the period between 2015 and 2022.The results of this scoping review are discussed and presented separately in 3 articles. This second paper synthesizes research evidence on the risk factors, diagnostic methods and treatment of infection in adult patients undergoing left ventricular assist device implantation.

RESULTS

The initial searches identified 771 studies. Sixty-nine patients met the eligibility criteria and were included in the scoping review. Forty-three articles addressing the risk factors, diagnosis and treatment of infection were included to answer the questions of this review.

CONCLUSION

Obesity has been shown to be the most common risk factor for the described process of infection by left ventricular assist devices.18F-fluorodeoxyglucose positron emission tomography showed high sensitivity in detecting cardiac device infection, and labeled leukocyte or gallium citrate-67 scintigraphy showed high specificity for left ventricular assist device infections; therefore, it can help differentiate infection from inflammation, particularly in patients with equivocal fluorodeoxyglucose positron emission tomography. Also, this review brings and discusses the limitations and strengths of diagnostic tests, the knowledge regarding the risk factors for left ventricular assist device infection, the therapeutic heterogeneity, the methodological issues of the studies, and the vast opportunity for future research on left ventricular assist device.

IMPLICATIONS FOR CLINICAL PRACTICE

Ventricular assist device professionals should evaluate risk factors prior to device implantation and periodically.18F-fluorodeoxyglucose positron emission tomography should be considered as diagnostic tool in detecting superficial and deep driveline infections. Early treatment, including chronic suppressive therapy and serial surgical debridement, combined with driveline exteriorization and delayed driveline relocation may constitute a potential therapeutic strategy for deep driveline infections.

Argon Cold Plasma Use and Driveline Infection in Left Ventricular Assist Device Implant Recipients

We conducted a prospective open-labeled, clinical trial, with a two-by-two factorial design, of argon cold plasma (ACP) application and two different types of driveline positioning for the prevention of driveline infection (DLI) in patients with a left ventricular assist device (LVAD) implant. Here, we present the results of ACP application versus no ACP application. Eighty patients were allocated to the control group (no preventive ACP use; n = 40) or ACP group (preventive ACP use for 30 days post-LVAD implantation; n = 40). Patients were followed up for 1 year. The secondary endpoint was survival on device. Preventive ACP use improved 30 day freedom from DLI significantly (100% vs. 85%; p = 0.012); results remained significant at 6 months (92% vs. 69%, p = 0.007) and were 55% and 60%, respectively ( p = 0.65) at 1 year follow-up. With respect to survival on device, results in the control and ACP groups did not differ significantly at 30 days (97.5% vs. 100%, respectively; p = 0.32), but tended to be lower in the control group than in the ACP group at 1 year follow-up (74% vs. 90%, respectively; p = 0.09). In conclusion, preventive ACP use was able to significantly reduce DLI both during the application period and up to 6 months after LVAD implantation.