Late-Breaking Science: Oral step-down antibiotics for endocarditis – what is the effect on outcomes in clinical practice?
26 Aug 2023
In a Late-Breaking Science session yesterday, Doctor Mia Pries-Heje (Rigshospitalet, Copenhagen University Hospital - Copenhagen, Denmark) presented an analysis exploring clinical implementation of the oral step-down antibiotic therapy regimen used in the POET trial in infective endocarditis (IE).1
The POET trial changed the paradigm of antibiotic therapy for left-sided IE by challenging the notion that antibiotics should always be given intravenously.1 The trial demonstrated that after an initial phase of intravenous treatment, it was safe to complete the treatment using oral antibiotics, which made out-patient treatment possible.1
In the POETry analysis, Dr. Pries-Heje and colleagues investigated long-term outcomes after a POET-based oral step-down antibiotic therapy regimen was included in Danish Guidelines for Infective Endocarditis in May 2019. Data were retrospectively collected by medical chart review from patients diagnosed with IE from May 2019 and until December 2020 in Denmark. Patients were considered possible candidates for oral antibiotics if they had left-sided IE with blood cultures positive for streptococcus, Enterococcus faecalis, Staphylococcus aureus or coagulase-negative staphylococci. The primary outcome was a composite of embolism, nonplanned heart valve surgery, relapse of bacteraemia or all-cause mortality from the end of antibiotic treatment until the end of follow-up.
In total, 562 patients were considered possible candidates for oral antibiotics, and of these, 240 (43%) were switched to oral antibiotics at the discretion of the treating physician, leaving 322 (57%) to receive conventional intravenous treatment. Median patient age was 74 years and 30% were female. Patients receiving oral antibiotics underwent surgery less often and were less likely to have a pre-existing pacemaker/implantable cardioverter-defibrillator, intracardiac abscess formation or S. aureus infection. Median length of stay was 19 days shorter in the oral group (24 days; IQR 17–36) than in the intravenous group (43 days; IQR 32–51; p<0.001).
After median 21 months of follow-up, the composite primary outcome occurred in 30% of patients who received oral antibiotics and 38% who received intravenous antibiotics (p=0.056).
Furthermore, all-cause mortality was lower in patients who received oral versus intravenous antibiotics (22% versus 32%; p=0.019).
Summing up, Dr. Pries-Heje says, “More than 40% of possible candidates were switched to oral antibiotics within the first 1.5 years after introducing the new Danish guidelines and these patients’ length of stay was considerably reduced. Although the lower all-cause mortality might, to some extent, relate to case selection, these long-term results are encouraging and further support the safety of oral step-down antibiotics in stabilised patients with endocarditis.”
- Iversen K, et al. N Engl J Med. 2019;380:415–424.