Ceftazidime-avibactam and aztreonam combination for Carbapenem-resistant Enterobacterales bloodstream infections with presumed Metallo-β-lactamase production: a systematic review and meta-analysis

INTRODUCTION: Carbapenem-resistant Enterobacterales (CRE) due to Metallo-β-lactamase (MBL) production are treated with either polymyxins or the novel combination of ceftazidime-avibactam and aztreonam (AA). This study aims to evaluate the 30-day mortality of AA in patients with BSI caused by MBL-CRE infections. METHODOLOGY: In this systematic review and meta-analysis, all articles up to June 2023 were screened using search terms like 'CRE', 'MBL', 'AA' and 'polymyxins'. The risk ratio for AA vs polymyxins was pooled using a random-effect model, and the results were represented by a point estimate with a 95% confidence interval. RESULTS: < 0.001. There was no significant heterogeneity. CONCLUSION: The meta-analysis from studies with a high risk of bias shows that AA is associated with lesser 30-day mortality when compared to polymyxins in patients with MBL-producing CRE BSI. Registration with PROSPERO- CRD42023433608.