Molecular Approach to Diagnosis of Cardiovascular Implantable Electronic Device Infection

BACKGROUND

Sonicate fluid (SF), a solution derived from vortexing and sonication of explanted cardiovascular implantable electronic devices (CIEDs), is a higher-yield specimen compared with swabs or tissues for culture-based detection of microorganisms associated with CIED infection. Despite this, SF culture fails to identify a causative organism in ~50% of cases. We aimed to evaluate the diagnostic performance of 16S ribosomal RNA gene (rRNA) polymerase chain reaction (PCR)/sequencing of SF and compare it with that of SF culture.

METHODS

We identified 322 SF specimens from extracted CIEDs and reviewed clinical data for each patient. Subjects were classified as having or not having CIED infection. Cases were subcategorized as culture negative if no significant growth was reported from SF cultures and as culture positive if an organism was detected above predefined thresholds. 16S rRNA PCR/sequencing was performed, with the organisms identified reported according to Clinical and Laboratory Standards Institute guidelines for sequence data interpretation.

RESULTS

A total of 278 SF samples corresponded to infected cases, of which 160 were culture positive and 118 culture negative. The remaining 44 were from noninfected cases, of which 2 were culture positive. Compared with SF culture, the sensitivity of 16S rRNA PCR/sequencing was higher (64% vs 57.5%, P = .003). 16S rRNA PCR/sequencing detected a potential pathogen in 28 of 118 culture-negative cases, identifying staphylococci in the majority (18/28).

CONCLUSIONS

16S rRNA PCR/sequencing has higher sensitivity to detect bacteria in SF from extracted CIEDs than does SF culture.

Lead Extraction for Cardiovascular Implantable Electronic Device Infection in Patients With Left Ventricular Assist Devices

OBJECTIVES

The goal of this study was to assess the utility of transvenous lead extraction for cardiovascular implantable electronic device (CIED) infection in patients with a left ventricular assist device (LVAD).

BACKGROUND

The use of transvenous lead extraction for the management CIED infection in patients with a durable LVAD has not been well described.

METHODS

Clinical and outcomes data were collected retrospectively among patients who underwent lead extraction for CIED infection after LVAD implantation at Duke University Hospital.

RESULTS

Overall, 27 patients (n = 6 HVAD; n = 15 HeartMate II; n = 6 Heartmate III) underwent lead extraction for infection. Median (interquartile range) time from LVAD implantation to infection was 6.1 (2.5 to 14.9) months. Indications included endocarditis (n = 16), bacteremia (n = 9), and pocket infection (n = 2). Common pathogens were Staphylococcus aureus (n = 10), coagulase-negative staphylococci (n = 7), and Enterococcus faecalis (n = 3). Sixty-eight leads were removed, with a median lead implant time of 5.7 (3.6 to 9.2) years. Laser sheaths were used in all procedures, with a median laser time of 35.0 s (17.5 to 85.5s). Mechanical cutting tools were required in 11 (40.7%) and femoral snaring in 4 (14.8%). Complete procedural success was achieved in 25 (93.6%) patients and clinical success in 27 (100%). No procedural failures or major adverse events occurred. Twenty-one patients (77.8%) were alive without persistent endovascular infection 1 year after lead extraction. Most were treated with oral suppressive antibiotics after extraction (n = 23 [82.5%]). Persistent infection after extraction occurred in 4 patients and was associated with 50% 1-year mortality.

CONCLUSIONS

Transvenous lead extraction for LVAD-associated CIED infection can be performed safely with low rates of persistent infection and 1-year mortality.