Clinical characteristics and outcomes of enterococcal infective endocarditis: an ancillary study from the ESC-EORP EURO-ENDO registry

Background Enterococci are a leading cause of infective endocarditis, ranking behind Staphylococcus aureus and Streptococci. There incidence is increasing, particularly among elderly patients, due to the widespread use of invasive medical devices and in the context of healthcare-associated infections. Enterococcal IE (EIE) is associated with multiple comorbidities, a high recurrence rate, and significant therapeutic challenges, particularly regarding the optimization of antibiotic regimens and the role of early surgery. The aim of this study was to describe the clinical characteristics, management strategies, and outcomes of patients with EIE compared to non-enterococcal IE (NEIE) within the ESC-EORP EURO-ENDO registry. Methods This ancillary study analyzed data from the EURO-ENDO registry, a prospective, multicenter observational study collecting data on definite or possible IE according to the modified Duke criteria. Patients diagnosed with IE between 2016 and 2018 were included. Clinical characteristics, microbiological profiles, imaging findings, therapeutic strategies, in-hospital and 1-year outcomes were compared between EIE and NEIE patients. Statistical analyses included chi-square and t-tests for group comparisons. Results Of 3,083 patients included in the registry, 365 (11.8%) had EIE and 2,718 (88.2%) had NEIE. Compared to NEIE, EIE patients were older (68 vs. 58 years, p < 0.001) and had a higher prevalence of chronic kidney disease (22.7% vs. 17.0%, p = 0.007), diabetes mellitus (30.1% vs. 21.6%, p < 0.001), and history of cancer (19.2% vs. 10.7%, p < 0.001). EIE was more frequently associated with prosthetic valve involvement (41.1% vs. 26.3%, p < 0.001) and aortic valve localization (64.5% vs. 47.6%, p < 0.001). Although there was no significant difference in embolic events or in-hospital mortality, EIE patients had higher rates of spondylitis (9.0% vs. 5.0%, p = 0.001) and colonic PET uptake. Conclusion EIE is characterized by a distinct clinical profile, including older age, higher burden of comorbidities, and increased prosthetic valve involvement. Despite comparable rates of embolic events, EIE patients exhibit specific imaging findings and were more frequently associated with colonic pathology. These findings highlight the need for tailored diagnostic and therapeutic approaches to improve outcomes in this high-risk population. Further analyses on healthcare-associated infections, IE recurrences, and comparisons with other bacterial etiologies are underway and will help refine management strategies and optimize treatment algorithms for enterococcal IE.