Vancomycin-resistant Enterococci Bacteremia: Risk Factors for Mortality and Influence of Antimicrobial Therapy on Clinical Outcome

Objectives: This study evaluated the effects of antimicrobial treatment against vancomycin-resistant enterococci (VRE) and delayed administration of anti-VRE therapy on mortality, and determined independent risk factors for delayed all-cause mortality of VRE bacteremia patients.

Methods: Over 10 years, 153 patients with clinically significant monomicrobial VRE bacteremia were identified among a total of 2834 patients in a VRE cohort. The main outcomes were immediate (7-day) and delayed (28-day, 60-day) all-cause mortality.

Results: The 7-day (P<0.001) and 28-day (P=0.041) mortalities were lower in the group receiving anti-VRE therapy, but the 60-day mortality (P=0.113) was unaffected. The mortalities of patients receiving anti-VRE therapy later than 72h after the onset of bacteremia were no different from that of patients receiving treatment within 72h. Both a higher APACHE II score (hazard ratio [HR], 1.10; P<0.001 and HR, 1.12; P<0.001, respectively) and the presence of septic shock at the onset of bacteremia (HR, 1.91; P=0.047 and HR, 1.78; P=0.034, respectively) were independent risk factors for 28-day and 60-day mortality.

Conclusion: These findings suggest that in spite of antibiotic therapy against VRE, patients with VRE bacteremia eventually have a higher risk of death because of severe illness at the onset of bacteremia.