Impact of Antibiotic Therapy with Ceftazidime Avibactam vs. Best Available Therapy in Adult Patients with Bacteremia Caused by Carbapenem-Resistant Enterobacterales.

Abstract

Background/Objectives: Carbapenem-resistant Enterobacterales (CRE) infection is associated with a higher mortality rate. The purpose of this study was to evaluate the effect of ceftazidime avibactam (CZA) for treating bacteremia caused by CRE compared to the best available therapy in an area where these microorganisms are endemic. Methods: A retrospective cohort study of patients with CRE bacteremia was conducted. We included adults with CRE bacteremia who were treated with CZA or the best available therapy (BAT) for more than 48 h, and the hospitalization time was recorded. The outcomes included death during hospitalization, relapse, and microbiological cure. Confounders were adjusted using propensity score-derived stabilized inverse probability of treatment weighting (IPTW). Results: A total of 169 patients with CRE bacteremia were included. About 72.6% of isolates had a class A serin carbapenamase, and 20.4% had metallo-β-lactamase co-production. A total of 107 patients were treated with CZA, 63% in monotherapy and 32% with aztreonam (ATM). Crude mortality during hospitalization was 36 (34.5%) in patients treated with CZA and 21 (33.2%) with BAT. No difference was observed between death rates (HR 0.86: IC 95% 0.40-1.83), microbiological cure (OR 1.31 IC 95% 0.46-3.67), clinical response (OR 1.39 IC 95% 0.35-5.43), acute kidney injury (OR 0.56 IC 95% 0.11-2.80) or relapse (OR 0.99 IC 95% 0.17-5.51) during the hospitalization after the adjustment. Conclusions: Among adult patients with CRE, no differences were observed between treatments with CZA and BAT after adjustment with IPTW.