Ceftazidime-avibactam in the treatment of infections from carbapenem-resistant Klebsiella pneumoniae: Ceftazidime-avibactam against CR-KP infections.

BACKGROUND Clinical experience with Ceftazidime-avibactam (CAZ-AVI) for the treatment of carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections are not well evaluated. Our aim is to assess its efficacy in a single-centre cohort of patients infected with CR-KP. METHODS We conducted a retrospective observational study of patients consecutive treated for>72 hours with CAZ-AVI or other active antibiotics (OAAs) for CR-KP infections. The primary outcome was 30-day mortality. The secondary outcomes were 14-day clinical failure and 14-day microbiological failure. Multivariate regression and propensity score matching was used to evaluate the relationship between CAZ-AVI treatment and outcomes. RESULTS 90 infections caused by CR-KP were documented in our study. 42 patients were treated with CAZ-AVI and 48 with OAAs. The crude 30-day mortality (8/42 vs. 22/48, p=0.007), 14-day clinical failure (14/42 vs. 24/48, p=0.046), and 14-day microbiological failure (11/42 vs. 15/48, p=0.034) were significantly lower in patients with CAZ-AVI treatment. The Kaplan-Meier survival curves of 30-day mortality confirmed the findings (logrank=0.004). In the multivariable models, the odds ratio (OR) of 30-day mortality (OR 0.23 95%CI 0.10-0.51, p 5, OR 0.13, 95%CI 0.04-0.36, p 3, OR 0.15, 95%CI 0.04-0.55, p=0.004). After propensity score matching, 29 cases from each group were well matched. The 30-day mortality remained significantly lower in the CAZ-AVI group (6/29 vs. 13/29, p=0.05). CONCLUSION CAZ-AVI may be a more valuable therapeutic option for severe CR-KP infections than for mild cases and further randomized controlled trials are needed to evaluate the efficacy.