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

Abstract

BackgroundReports 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.MethodsRetrospective 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.ResultsA 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.ConclusionIn 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. 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.