Abstract 16397: Inflammatory Biomarkers as Predictors of Systemic vs. Isolated Pocket Infection in Patients Undergoing Transvenous Lead Extraction

Intro: Cardiovascular implantable electronic device (CIED) infections are a common indication for device extraction. Early diagnosis and complete device and lead removal are crucial to reduce morbidity and mortality. The lack of clear infectious symptoms and signs make the diagnosis of CIED infections challenging and may delay referral for extraction.

Methods: We performed a retrospective analysis of patients undergoing transvenous lead extraction for CIED infection at UCSD from 2012 to 2022 (n= 164). Our control group underwent extraction for non-infectious etiologies such as device malfunction, lead fracture or system upgrade (n=281). Patients were classified as systemic infection (n=88) or isolated pocket infection (n=68) based on the presence or absence of sepsis. Prospectively collected pre-operative procalcitonin (PCT), C-reactive protein (CRP), and white blood cell count (WBC) were compared between groups using Kruskal-Wallis and Dunn-Bonferroni tests.

Results: PCT and WBC medians differed significantly between the systemic infection, the pocket infection, and the control groups (p<0.001 and p=0.021 respectively). Pairwise comparisons revealed the systemic infection group had a higher PCT than the control group (p<0.001), as well as the pocket infection group (p=0.009). There was no significant difference in PCT between the control group and the isolated pocket infection group (p=0.685). Regarding pairwise differences in WBCs, a higher value was only associated with systemic infection when compared with our control group (p=0.018). CRP levels were not significantly different between groups (p=0.117) and the difference was again limited to systemic infection vs control groups (p=0.017).

Conclusion: In patients with CIED infections requiring extraction, systemic infection was associated with elevated pre-operative PCT when compared to isolated pocket infection and controls. Elevated WBCs and CRP levels were also associated with systemic infection. However, inflammatory biomarkers including PCT were not elevated in isolated pocket infections. The results suggest that inflammatory markers are not predictive to help with the diagnosis of pocket infections, which ultimately requires a high level of clinical suspicion.