EC Clinical and Medical Case Reports

Aim of the Study: The aim of the report is to present a late prosthetic valve endocarditis with an unusual localization, successfully diagnosed and treated with combined imaging modalities and antibiotic therapy.

Case Report: We report a case of a 55-year-old female with a history of rheumatic mitral stenosis, who underwent mitral valve replacement with a mechanical prosthesis ten years earlier. Two months before admission, she developed recurrent episodes of fever, elevated inflammatory markers, and malaise, partially responsive to empirical antibiotic therapy. On admission, she presented with high-grade fever, fatigue, and elevated inflammatory markers. Transthoracic echocardiography (TTE) revealed a mobile mass measuring 4-5 mm beneath the mitral prosthesis, in an unusual sub valvular location. Three-dimensional transthoracic echocardiography (3D TTE) and transesophageal echocardiography (TEE) confirmed the presence of a mobile echogenic structure without interference with prosthetic function. Blood cultures were positive for Staphylococcus epidermidis. The patient was treated with dual intravenous antibiotic therapy guided by antibiogram for three weeks, followed by sequential oral therapy for an additional five weeks. Clinical symptoms resolved, inflammatory parameters normalized, and no recurrence was observed during a six-month follow-up.

Conclusion: This case highlights the diagnostic challenges of prosthetic valve endocarditis, particularly with atypical localization of vegetations. It underscores the importance of multimodality imaging, microbiological confirmation, and guideline-directed antimicrobial therapy, as well as the critical role of close follow-up in achieving favorable outcomes.

 Keywords: Prosthetic Endocarditis; Infective Endocarditis; Comprehensive Diagnostic Evaluation; Echocardiography; Staphylococcus epidermidis; Antibiotic Treatment

1. Habib G., et al. “2023 ESC Guidelines for the management of endocarditis”. European Heart Journal 39 (2023): 3948-4046.
2. Habib G., et al. “2015 ESC Guidelines for the management of infective endocarditis”. European Heart Journal 44 (2015): 3075-3128.
3. Habib G., et al. “Clinical presentation, aetiology and outcome of infective endocarditis. Results of the ESC-EORP EURO-ENDO (European infective endocarditis) registry: a prospective cohort study”. European Heart Journal 39 (2019): 3222-3232.
4. Moreillon P and Que YA. “Infective endocarditis”. Lancet 9403 (2004): 139-149.
5. Hoen B., et al. “Changing profile of infective endocarditis: results of a 1-year survey in France”. Journal of the American Medical Association1 (2002): 75-81.
6. Anantha Narayanan M., et al. “Early versus late surgical intervention or medical management for infective endocarditis: a systematic review and meta-analysis”. Heart 12 (2016): 950-957.
7. Tornos P., et al. “Infective endocarditis in Europe: lessons from the Euro heart survey”. Heart5 (2005): 571-575.
8. Tubiana S., et al. “Dental procedures, antibiotic prophylaxis, and endocarditis among people with prosthetic heart valves: nationwide population based cohort and a case crossover study”. British Medical Journal 358 (2017): j3776.
9. Wang A., et al. “Contemporary clinical profile and outcome of prosthetic valve endocarditis”. Journal of the American Medical Association12 (2007): 1354-1361.
10. Prendergast BD and Tornos P. “Surgery for infective endocarditis: who and when?” Circulation9 (2010): 1141-1152.
11. Cahill TJ and Prendergast BD. “Infective endocarditis”. Lancet10021 (2016): 882-893.
12. Murdoch DR., et al. “Clinical presentation, etiology, and outcome of infective endocarditis in the 21^st century: the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS)”. Archives of Internal Medicine 5 (2009): 463-473.
13. Baddour LM., et al. “Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications: a scientific statement from the American Heart Association”. Circulation15 (2015): 1435-1486.
14. Saby L., et al. “Positron emission tomography/computed tomography for diagnosis of prosthetic valve endocarditis”. Journal of the American College of Cardiology 23 (2013): 2374-2382.
15. Chu VH., et al. “Native valve endocarditis and prosthetic valve endocarditis”. Current Infectious Disease Reports 4 (2004): 279-285.
16. Habib G., et al. “Clinical presentation, aetiology and outcome of infective endocarditis. Results of the ESC-EORP EURO-ENDO registry”. European Heart Journal 39 (2019): 3222-3232.
17. Fernández-Hidalgo N., et al. “Prognosis of left-sided infective endocarditis in patients transferred to a referral hospital—prospective analysis of referral bias and influence of inadequate antimicrobial treatment”. Clinical Infectious Diseases 2 (2011): 174-180.
18. Iversen K., et al. “Partial oral versus intravenous antibiotic treatment of endocarditis (POET): a randomized controlled trial”. New England Journal of Medicine 5 (2019): 415-424.