2441. Outcomes of Patients With Vancomycin-Resistant Enterococcus Blood Stream Infections (BSI) Treated With Daptomycin

BACKGROUND: Reports of poor outcomes in patients (patients) infected with VRE strains with daptomycin (DAP) minimum inhibitory concentrations (MIC) near the susceptible breakpoint (<=4 μg/ml) are noted in the literature. We assessed the relationship of clinical outcomes for patients treated with DAP to the initial MIC. METHODS: Retrospective study of consecutive adult patients with VRE BSI treated with DAP for at least 48 hours (November 2011–January 2015) in a tertiary hospital in Cleveland, OH. Patients were grouped based on the initial DAP MIC (MIC ≤ 2 μg/mL and MIC = 4 μg/mL) determined by a commercial broth microdilution method (Sensititre). Demographic and clinical data were extracted via EMR. Outcomes for all-cause mortality at 30 days (30-D mortality) and 90 days (90-D mortality), 30-day mortality attributed directly to VRE BSI (30-D mortality VRE) and microbiological failure (MF) were measured. MF was defined as duration of bacteremia ≥4 days after at least 48 hours of DAP use and achievement of source control when possible. We also assessed the impact of concomitant β-lactam use on MF. RESULTS: A total of 192 patients were identified. Baseline characteristics are shown in Table 1. Outcomes for MF, 30-D mortality VRE, 30-D mortality and 90-D mortality are shown in Table 2. Impact of concomitant β-lactam use on MF is shown in Figure 1. CONCLUSION: In this retrospective study, MF and mortality were not significantly higher for BSI caused by VRE with DAP MICs of 4 μg/ml, regardless of concomitant β-lactam use. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: S. S. Richter, bioMerieux: Grant Investigator, Research grant. BD Diagnostics: Grant Investigator, Research grant. Roche: Grant Investigator, Research grant. Hologic: Grant Investigator, Research grant. Diasorin: Grant Investigator, Research grant. Accelerate: Grant Investigator, Research grant. Biofire: Grant Investigator, Research grant.