681. Epidemiology and Outcomes of Patients with Carbapenem-Resistant Bloodstream Infection in United States Hospitals, 2010–2015

BACKGROUND: Carbapenem resistance (CR) in patients with Gram-negative (GN) bloodstream infections (BSI) presents a mounting therapeutic challenge. To gain a better understanding of CR among patients in US hospitals, we explored their characteristics and outcomes. METHODS: We performed a retrospective cohort analysis of consecutive adult patients (age ≥18 years) with a positive blood culture for GN pathogens (11 most prevalent pathogens reported in ~53,811 study patient samples), hospitalized in one of 181 institutions contributing microbiology data to the Premier Healthcare Database (October 2010–September 2015). We compared patients with CR vs. carbapenem-susceptible (CS) BSIs based on their characteristics and outcomes. Primary outcome was mortality, and secondary outcomes included post-index culture hospital and ICU lengths of stay (LOS), and likelihood of being discharged home. RESULTS: Of the ~53,811 study patient samples, 46,381 patients had a GN BSI, with the prevalence of CR occurring at 3.5% (n = 1,602). Compared with patients with CS, those with CR were younger (mean/SD 60.4/17.1 vs. 67.4/16.4 years, P < 0.01), more likely to be male (52.8% vs. 45.9%, P < 0.01), black (22.7% vs. 17.7%, P < 0.01), and had Medicaid as a payor (18.1% vs. 10.9%, P < 0.01). The mean/SD Charlson Comorbidity Index was higher in CR than CS group (2.9/2.5 vs. 2.3/2.5, P < 0.01). Crude mortality was also higher (20.6% vs. 9.7%, P < 0.01) in the setting of CR than CS, as were unadjusted median (IQR) post-index culture hospital (9 [6, 15] vs. 7 [5, 10] days, P < 0.01), and ICU (5 [2, 11] vs. 3 [2, 6] days, P < 0.01) LOS. Patients with CR BSI were less likely to be discharged home than those with CS (32.7% vs. 53.8%, P < 0.001). CONCLUSION: Patients with CR BSIs have lower likelihood of surviving hospitalization or being discharged home, and longer post-index culture hospital and ICU LOS, compared with those with CS BSIs. This highlights the need for better and more preventive and therapeutic strategies aimed at combating GN CR. DISCLOSURES: A. F. Shorr, Astellas: Consultant and Speaker’s Bureau, Consulting fee, Research support and Speaker honorarium Cidara: Consultant, Consulting fee. Merck & Co.: Consultant and Speaker’s Bureau, Consulting fee, Research support and Speaker honorarium. T. P. Lodise Jr., Motif BioSciences: Board Member, Consulting fee.