1826. Impact of Rapid Diagnostics and Ceftazidime–Avibactam on Mortality after Bacteremia Caused by Carbapenem-Resistant Enterobacteriaceae

BACKGROUND: Patients with bloodstream infections (BSIs) due to carbapenem-resistant Enterobacteriaceae (CRE) have long delays until receipt of appropriate antimicrobial therapy and high mortality rates. Rapid molecular diagnostics and novel therapies, such as ceftazidime–avibactam (CAZ-AVI), offer promise to improve outcomes, but their clinical impact is unclear. METHODS: We conducted an observational study of patients with CRE BSI from January 2016 to June 2018 at 8 New York and New Jersey medical centers. Patient demographics, comorbidities, clinical presentations, diagnostic methods, and treatments were compared between patients who died within 30 days of BSI onset and survivors. Independent risk factors for mortality were identified using logistic regression. We then compared time to receipt of active antimicrobial therapy between patients whose positive blood culture bottles underwent testing for the Klebsiella pneumoniae carbapenemase gene (blaKPC PCR) and patients where this test was not used. RESULTS: We identified 178 patients with CRE BSI (K. pneumoniae: n = 104, 58%; Enterobacter cloacae: n = 26, 15%; Escherichia coli: n = 26, 15%). The 30-day mortality rate was 38%. An increasing Acute Physiology and Chronic Health Evaluation II score (adjusted odds ratio [aOR] 1.06, P = 0.005) was independently associated with increased 30-day mortality; whereas, use of blaKPC PCR (aOR 0.31, P = 0.005), urinary tract source (aOR 0.12, P = 0.001), and source control (aOR 0.25, P = 0.001) were independently associated with survival. Initial targeted therapy with CAZ-AVI was associated with a 28% 30-day mortality rate, compared with a 49% 30-day mortality rate among patients who received a polymyxin or aminoglycoside (P = 0.036). Patients whose blood culture underwent blaKPC PCR were more likely to receive active antimicrobial therapy within 24 hours of BSI onset (42% vs. 28%; P = 0.07) and had a decreased median time until receipt of active therapy (25 hours vs. 46 hours; P = 0.07), although these differences did not achieve statistical significance. CONCLUSION: The use of PCR to rapidly identify blood cultures with blaKPC and definitive therapy with CAZ-AVI instead of polymyxins or aminoglycosides were associated with decreased mortality after CRE bacteremia. DISCLOSURES: All Authors: No reported Disclosures.