Abstract
Abstract Background. Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) can cause significant morbidity and mortality in patients with cancer. However, data
on outcomes of patients treated with vancomycin are lacking.
Methods. We identified
223 patients with cancer who developed MRSA BSIs between January 2001
and June 2009 and were treated with vancomycin.
Treatment failure was defined as death within 60
days of infection, persistent bacteremia ≥5 days, fever ≥4 days,
recurrence
or relapse, and secondary MRSA infection.
Results. The treatment
failure rate was 52% (116 of 223 patients). These patients were more
likely to have been hospitalized, been
treated with steroids within the previous 3
months, developed acute respiratory distress syndrome, required
mechanical ventilation,
required intensive care unit care, and
community-onset infections (all p < .05). Risk factors for
MRSA-associated mortality (27 of 223 patients; 12%) included hematologic
malignancy and hematopoietic
stem cell transplantation, community-onset
infection, secondary BSI, MRSA with minimum inhibitory concentration
(MIC) ≥2.0
μg/mL, mechanical ventilation, and a late switch
to an alternative therapy (≥4 days after treatment failure; all p
< .05). On multivariate analysis, mechanical ventilation and recent
hospitalization were identified as independent predictors
of vancomycin failure, and community-onset
infection, secondary BSIs, and MIC ≥2 μg/mL were identified as
significant predictors
of MRSA-associated mortality.
Conclusions. We found a
high treatment failure rate for vancomycin in patients with cancer and
MRSA BSIs, as well as a higher mortality.
A vancomycin MIC ≥2 μg/mL was an independent
predictor of MRSA-associated mortality. An early switch to an
alternative therapy
at the earliest sign of failure may improve
outcome.
