Clinical effectiveness of cefiderocol for the treatment of bloodstream infections due to carbapenem-resistant Acinetobacter baumannii during the COVID-19 era: a single center, observational study

Background We assessed the clinical efectiveness of cefderocol (CFDC) in comparison with colistin (COL) for the treatment of carbapenem-resistant Acinetobacter baumannii (CRAB) bloodstream infections (BSI). Materials/methods Retrospective cohort study including adults with CRAB-BSI. Outcomes were mortality, clinical cure and adverse events during therapy. The average treatment efect of CFDC compared to COL was weighted with the inverseprobability treatment weight (IPTW). Results Overall, 104 patients were included (50 CFDC, 54 COL), median age 66.5 years, median Charlson Comorbidity Index 5, septic shock in 33.6% of patients. Primary BSI accounted for 43.3% of cases, followed by ventilator-associated pneumonia (VAP) (26%), catheter-related BSI (20.2%) and hospital-acquired pneumonia (HAP) (9.6%). Although not signifcantly, mortality at all time points was lower for CFDC than COL, while clinical cure was higher in CFDC than COL (66% vs. 44.4%, p=0.027). Adverse events were more frequent in COL than CFDC-group (38.8% vs. 10%, p<0.0001), primarily attributed to acute kidney injury (AKI) in the COL group. Patients with bacteremic HAP/VAP treated with CFDC had a signifcant lower 30-d mortality and higher clinical cure than COL (p=0.008 and p=0.0008, respectively). Increment of CCI (p=0.005), ICU (p=0.025), SARS-CoV2 (p=0.006) and ECMO (p<0.0001) were independently associated with 30-d mortality, while receiving CFDC was not associated with survival. Conclusions CFDC could represent an efective and safe treatment option for CRAB BSI, especially in patients with bacteremic HAP/VAP and frail patients where the risk of acute renal failure during therapy should be avoided