The AZAVI study is a multicenter observational registry (ICU and Infectious Diseases departments), designed to evaluate the real-world use of aztreonam-avibactam for suspected or documented infections caused by metallo-β-lactamase (MBL)-producing Enterobacterales or highly resistant Gram-negative bacteria. The study combines a retrospective cohort (patients treated during the 12 months prior to the drug's hospital availability) and a prospective cohort (patients consecutively included over 24 months).
The primary outcome is clinical success at day 7 after antibiotic discontinuation, defined as resolution of signs and symptoms of infection without recurrence or need for additional active therapy. Secondary outcomes include microbiological eradication, 14-day and 28-day all-cause mortality, infection relapse, length of stay, safety outcomes, and predictors of treatment failure.
Data will be collected using a standardized CRF, including demographics, severity scores, infection site and pathogens, therapeutic regimens, organ failures and support, adverse events, and outcomes. Descriptive statistics and multivariable models will be used to assess real-world effectiveness, identify determinants of clinical response, and inform stewardship strategies. This registry will provide the first national-scale evidence on the role of aztreonam-avibactam in critically ill patients outside the framework of controlled clinical trials.