1069. Combination Therapy Did Not Reduce 30-day Treatment Failure in Patients With Staphylococcus aureus Bacteremia (SAB)
Session: Poster Abstract Session: Clinical Infectious Diseases: Bacteremia and Endocarditis
Friday, October 28, 2016
Room: Poster Hall

Background: Favorable outcomes have been reported when antibiotic combinations are used as salvage therapy in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. However there are few large prospective studies to examine whether combination (combo) therapy reduces treatment failure in all patients with SAB. Methods: Adults with monomicrobial SAB from two prospective observational cohorts were included. Treatment failure was a composite of all-cause mortality, persistent bacteremia (³ 7 days) and recurrent bacteremia within 30 days. Receipt of ³ 2 concurrent anti-staphylococcal agents was considered combo therapy. Predictors of treatment failure were analyzed in a multivariable logistic regression model; a propensity score was used to account for selection bias. Results: 561 patients were analyzed, with 126 experiencing treatment failure. Two-thirds of patients received combo therapy at any time during the 30-day period after onset of SAB (385/561); 29.1% received combo therapy ³ 7 days. Figure 1 shows the frequency of common combinations. Combo therapy was associated with younger age, liver disease, immunosuppression, intensive care unit admission, and elevated C-reactive protein. Combo treatment as empiric therapy or at any time during 30 days after onset of SAB was not associated with reduced treatment failure (p=0.639; p=0.330 respectively), even in the subset with MRSA bacteremia (p=0.922; p=0.382 respectively). Propensity score analysis for combo therapy using quintile adjustment did not reveal any association with reduced treatment failure (p=0.619). Conclusion: Significant diversity in antibiotic combo regimens was observed in this large prospective multi-center cohort. Receipt of combo therapy, either as empiric therapy or at any time during 30 days after onset of SAB, was not associated with reduced 30-day treatment failure. Large randomized controlled trials are required to determine the benefit of combo therapy in SAB.

Figure 1.  Frequency of commonly prescribed combination regimen types and combinations containing multiple agents1.

1 Frequency represents individual combinations; patients could receive more than one combination regimen during the treatment period.

Natasha Holmes, MBBS FRACP PhD, Department of Infectious Diseases, Austin Health, Heidelberg VIC, Australia, J Owen Robinson, MD FRACP, Department of Microbiology and Infectious Diseases, Royal Perth Hospital & Fiona Stanley Hospital, Perth WA, Australia, Sebastian Van Hal, MBBS FRACP FRCPA PhD, Infectious Diseases and Microbiology, Royal Prince Alfred Hospital, Sydney, Australia, Wendy Munckhof, MBBS FRACP FRCPA PhD, Infection Management Services, Princess Alexandra Hospital, Woolloongabba QLD, Australia, Eugene Athan, MBBS, FRACP, MPH, Infectious Diseases, Barwon Health, Deakin University, Geelong, Australia, Tony Korman, MBBS FRACP FRCPA, Department of Infectious Diseases, Monash Infectious Diseases, Clayton VIC, Australia, Allen C. Cheng, MBBS, FRACP, MPH, PhD, Infection Prevention and Hospital Epidemiology Unit, The Alfred Hospital, Melbourne, Australia, Matthew O'sullivan, MBBS MMed FRACP FRCPA PhD, Centre for Infectious Diseases and Microbiology, Westmead Hospital, Westmead NSW, Australia, Tara Anderson, MBBS FRACP, Department of Infectious Diseases,, Royal Hobart Hospital, Hobart TAS, Australia, Sally a. Roberts, MBChB, FRACP, FRCPA, Labplus, Department of Microbiology, Auckland District Health Board, Auckland, New Zealand, Sanchia Warren, MBBS FRACP, Department of Infectious Diseases, Royal Hobart Hospital, Hobart TAS, Australia, John Turnidge, MBBS FRACP FRCPA, Australian Commission on Safety and Quality in Health Care, Sydney NSW, Australia, Benjamin Howden, MBBS FRACP FRCPA PhD, Microbiological Diagnostic Unit, Parkville VIC, Australia, Paul Johnson, MBBS FRACP PhD, Infectious Diseases, Austin Health/University of Melbourne, Melbourne, Australia and VANESSA study group


N. Holmes, National Health and Medical Research Council: Grant Investigator , Grant recipient

J. O. Robinson, None

S. Van Hal, None

W. Munckhof, None

E. Athan, None

T. Korman, None

A. C. Cheng, None

M. O'sullivan, None

T. Anderson, None

S. A. Roberts, None

S. Warren, None

J. Turnidge, None

B. Howden, National Health and Medical Research Council: Grant Investigator , Grant recipient

P. Johnson, None

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