Gram Negative Bacterial Infections in CIED Infection-Related Extractions – Clinical Course and Outcomes - The 68th Annual Conference of the Israel Heart Society in association with the Israel Society of Cardiothoracic Surgery

Anat Berkovitch ^1,2 Anat Wieder ^2,3 Anat Milman ^1,2 Eran Leshem ^1,2 Michael Glikson ⁴ David Luria ⁵ Roy Beinart ^1,2 Eyal Nof ^1,2

¹Division of Cardiology, Leviev Heart and Vascular Center, Chaim Sheba Medical Center, Israel
²Sackler School of Medicine, Tel-Aviv University, Israel
³Infectious Disease Unit, Chaim Sheba Medical Center, Israel
⁴Integrated Heart Center,, Shaare Zedek Medical Center, Israel
⁵The Heart Institute, Hadassah Ein-Karem Medical Center, Israel

Background: The vast majority of cardiac implantable electronic device (CIED) related infections are caused by gram positive (GP) bacteria. Furthermore, routine pre-procedural antibiotics do not cover most GN infections. Patients’ characteristics and outcomes of those infected gram negative (GN) bacterial infections are not well defined.

Aims: To identify possible risk factors for contracting GN infection and their prognosis compared to GP related CIED.

Methods: A retrospective analysis of all CIED extraction procedures from 01/2010 to 12/2018 was performed. Only records with confirmed culture growth, either pocket, blood and/or lead cultures, were included in the study population. The study population was divided according to the type of pathogen, for comparison between GP and GN cases.

Results: A total of 244 CIED extraction procedures were performed due to infections. Of whom 189 (77%) patients had GP bacterial infections, 55 (22%) patients had GN infections. Older age was associated with increased risk for contracting a GN CIED related infection, no other significant changes at baseline were found between the two groups. The most common GN bacteria was Pseudomonas Aeruginosa (26 cases, 47%), followed by Klebsiella Pneumonia, Citrobacter, Enterobacter, E.Coli and Serratia (4 cases each, 7%). Positive pocket cultures were significantly more common among the GN group (76% vs. 48%, p<0.001) while positive blood cultures were more frequent with GP (65% vs. 38%, p<0.001). Lead cultures were similarly positive among the two groups (33% and 34%). Procedural complications were slightly higher in the GP group: stroke 1% vs. 0%, need for surgery 5% vs. 0% and bleeding 8.5% vs. 5.5%, none of which reached statistical significance. Intra procedural mortality was similar between the groups (1.6% vs. 1.8%). Long term mortality rates were similar between the two groups (45.5% and 46.6%, p-value=0.9).

Conclusions: GN infections account for a significant portion of infection-related extractions. Proper empiric coverage should be considered in selected patients such as older patients and in cases of clear-cut pocket infection.