Jesus Ruiz1, Paula Ramirez2, Pablo Concha3, Miguel Salavert-Lletí4, Esther Villarreal1, Monica Gordon3, Juan Frasquet5, Álvaro Castellanos-Ortega3. 1. Intensive Care Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Intensive Care Unit, Instituto de Investigación Sanitaria La Fe, Hospital Universitario y Politécnico La Fe, Valencia, Spain. 2. Intensive Care Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain. Electronic address: ramirez_pau@gva.es. 3. Intensive Care Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain. 4. Infectious Diseases Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain. 5. Microbiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
Abstract
OBJECTIVES: The aim of this study was to determine the persistence of the adverse prognostic effect of elevated vancomycin minimum inhibitory concentration (MIC) in methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in a setting with low vancomycin use. METHODS: A retrospective study focusing on episodes of bacteraemia due to MRSA diagnosed from January 2010 through December 2015 was designed. The main outcome measures were 30-day mortality and treatment failure. Multivariate logistic regression analysis was used to identify variables associated with patient mortality and treatment outcome. RESULTS: In total, 79 MRSA bacteraemia episodes were included. The vancomycin MIC was >1.0μg/mL in 53 episodes (67.1%). The presence of high vancomycin MIC was not associated with a higher mortality rate or treatment success. A daptomycin MIC≥0.5μg/mL was present in 16 (26.2%) of 61 episodes for which the daptomycin MIC was obtained and was associated with 30-day mortality in the multivariate analysis (odds ratio=4.72, 95% confidence interval 1.19-18.71). None of the antimicrobials used were associated with a lower risk of treatment failure or mortality. CONCLUSIONS: The pernicious effect of high vancomycin MIC disappears in the absence of a predominant use of this antibiotic. However, a high daptomycin MIC in MRSA bacteraemia is associated with higher mortality in patients with bacteraemia, irrespective of antimicrobial treatment choice.
OBJECTIVES: The aim of this study was to determine the persistence of the adverse prognostic effect of elevated vancomycin minimum inhibitory concentration (MIC) in methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in a setting with low vancomycin use. METHODS: A retrospective study focusing on episodes of bacteraemia due to MRSA diagnosed from January 2010 through December 2015 was designed. The main outcome measures were 30-day mortality and treatment failure. Multivariate logistic regression analysis was used to identify variables associated with patient mortality and treatment outcome. RESULTS: In total, 79 MRSA bacteraemia episodes were included. The vancomycin MIC was >1.0μg/mL in 53 episodes (67.1%). The presence of high vancomycin MIC was not associated with a higher mortality rate or treatment success. A daptomycin MIC≥0.5μg/mL was present in 16 (26.2%) of 61 episodes for which the daptomycin MIC was obtained and was associated with 30-day mortality in the multivariate analysis (odds ratio=4.72, 95% confidence interval 1.19-18.71). None of the antimicrobials used were associated with a lower risk of treatment failure or mortality. CONCLUSIONS: The pernicious effect of high vancomycin MIC disappears in the absence of a predominant use of this antibiotic. However, a high daptomycin MIC in MRSA bacteraemia is associated with higher mortality in patients with bacteraemia, irrespective of antimicrobial treatment choice.