Lines on the line: evaluating the impact of antibiotic lock therapy versus catheter removal in the management of central vascular catheter infections.

Objectives: To compare the efficacy and safety of antibiotic lock therapy (ALT) versus catheter removal in managing central vascular catheter-associated bloodstream infection (CVC-BSI).

Methods: We conducted a single-centre, retrospective cohort study of adult patients treated with ALT or catheter removal for management of CVC-BSI between 2018 and 2022. The primary outcome was a composite of 90 day microbiological relapse or recurrent BSI. Secondary outcomes included 30 day mortality, CVC-associated complications and Clostridioides difficile infection (CDI). Logistic regression with propensity score-adjustment was used to evaluate differences in outcomes and identify predictors of relapse.

Results: During the study period, 106 participants received ALT and 181 underwent catheter removal. Patients treated with ALT received shorter courses of systemic antimicrobials (11 versus 14 days; P < 0.001) and had shorter hospital stays (4 versus 10 days; P < 0.001). Median duration of catheter salvage in patients receiving ALT was 28 days (IQR 7-80). Primary composite outcome was similar between both groups, but ALT was associated with a significantly higher risk of microbiological relapse within 90 days (20% versus 7%; adjusted odds ratio 3.93, 95% CI 1.64-9.40; P = 0.002). No significant difference in 30 day mortality, CVC-related complications or CDI was observed. CoNS BSI was an independent predictor of microbiological relapse in patients treated with ALT (OR 2.28; P = 0.05).

Conclusions: Although ALT offers a non-invasive catheter salvage strategy, its association with higher relapse rates, particularly in CoNS BSI, suggests catheter removal should remain the preferred approach when feasible. ALT could be considered a short-term catheter salvage strategy for pathogens with low virulence when used with close surveillance.