IV–Oral Antibiotic Switch in Streptococcal and Enterococcal Endocarditis: Evaluating ESC Versus WikiGuideline Criteria

Background: The 2023 European Society of Cardiology (ESC) guideline and the 2023 WikiGuideline both support intravenous (IV)–oral antibiotic switch in selected patients with infective endocarditis but apply different eligibility criteria. We aimed to assess hypothetical eligibility according to both guideline sets and to describe actual IV–oral switch practice at our center. Methods: In this retrospective observational study, adult patients with possible or definite streptococcal or enterococcal infective endocarditis treated between January 2024 and January 2026 were included. Eligibility for IV–oral switch was retrospectively assessed according to the original ESC criteria and WikiGuideline criteria using a predefined hypothetical switch date. Actual IV–oral switches performed in clinical practice and their clinical outcomes were described separately. Results: Ninety patients were included. Based on the original ESC criteria, two patients (2.2%) were hypothetically eligible for IV–oral switch, compared with 67 patients (74.4%) according to the WikiGuideline criteria. The principal reason for ESC ineligibility was the absence of repeat transesophageal echocardiography before the hypothetical switch date. In clinical practice, 22 patients (24.4%) underwent IV–oral switch. None of these patients fulfilled original ESC eligibility criteria, whereas all fulfilled the WikiGuideline criteria. Clinical outcomes of patients who underwent IV–oral switch are presented descriptively. Conclusions: In this retrospective cohort, hypothetical eligibility for IV–oral switch differed substantially depending on whether the ESC or WikiGuideline criteria were applied. At our center, local imaging practice accounted for most ESC ineligibility. Prospective studies are needed to determine which eligibility criteria and imaging approaches best identify patients who can safely undergo IV–oral switch.