Switching to oral abx after 10 days as effective as 6 weeks of IV abx for stable left-sided endocarditis

Reference

Iversen K, Ihlemann N, Gill SU, et al. Partial oral versus intravenous antibiotic treatment of endocarditis. N Engl J Med 2019;380(5):415-424.

Synopsis

Current guidelines recommend at least 6 weeks of IV antibiotic therapy for patients with endocarditis of the left side of the heart. This study identified 400 patients with left-sided endocarditis who had been started on IV antibiotics for culture-proven streptococcus, Enterococcus faecalis, S. aureus, or coagulase-negative staphylococci. All patients were clinically stable and had received at least 10 days of IV antibiotics, and had no sign of abscess or valve abnormality that might require later surgery. Any patient who had undergone surgery was given at least 7 days of IV antibiotics after surgery prior to randomization. They were then randomized to continue to use IV antibiotics in the hospital, or to switch to an oral antibiotic based on the pathogen, sensitivities, and a prespecified protocol. The primary outcome was a composite of death, unplanned cardiac surgery, clinically evident embolic event, or bacteremic relapse, and was ascertained by a trial committee masked to treatment assignment. This was designed as a noninferiority trial, which is appropriate when you are comparing a cheaper, more convenient alternative to the standard of care. The mean age of participants was 67 years, 23% were women, and approximately half had streptococcus as the pathogen. At 6 months, there was no significant difference between groups in the primary outcome (9.0% oral versus 12.1% IV; odds ratio 0.72; 95% CI 0.37 - 1.36). Regarding the individual outcomes there were an identical number of embolic events, relapses, and surgeries between groups; there were 13 deaths in the IV group and 7 in the oral group, but this was not a statistically significant difference. Safety was similar between groups.