Prosthetic Aortic Valve Infective Endocarditis Caused by Methicillin-Susceptible Staphylococcus aureus with Multisystem Embolic Complications: A Case Report

Background: Prosthetic valve infective endocarditis (PVE) caused by Staphylococcus aureus is associated with high morbidity and mortality, particularly when complicated by peri-annular abscesses and systemic embolization.Case Summary: We report a 70-year-old male with a history of ischemic heart disease, coronary artery bypass grafting, and aortic valve replacement with a bioprosthesis. The patient presented with syncope, fever, and bilateral knee trauma. Blood cultures grew methicillin-susceptible Staphylococcus aureus, and a diabetic foot ulcer was identified as the likely portal of entry. Echocardiography revealed prosthetic valve thickening, an 8-mm mobile filamentous structure (vegetation), and peri-annular abscess. PET/CT confirmed prosthetic valve infection and involvement of both knee prostheses. MRI showed multiple cerebral embolic lesions and probable cervical spondylodiscitis. The patient received prolonged intravenous cefazolin and rifampicin. Multidisciplinary evaluation indicated early surgical intervention.Discussion: This case illustrates the aggressive nature of MSSA PVE, highlights the value of repeated and multimodal imaging including PET/CT, and emphasizes the importance of early multidisciplinary decision-making for surgical intervention.