Case of eustachian valve endocarditis and the importance of synergistic antibiotic therapy

A 46-year-old woman with a history of end-stage renal disease on chronic haemodialysis presented with 1 week of fever, chills, altered mental status and hand pain. She was febrile and ill-appearing on presentation with a pulse rate of 102 beats per minute. She had a tunnelled dialysis catheter in her right neck. Hand examination demonstrated a swollen, erythematous and tender wrist. Cardiovascular examination demonstrated no murmurs. CT of the hand showed abscesses involving the left forearm. Blood and abscess cultures grew methicillin-resistant Staphylococcus aureus (MRSA). Transesophageal echocardiography (TEE) showed a 1.0×1.0 cm mobile vegetation involving the eustachian valve (EV), confirming EV endocarditis. She remained bacteraemic for 18 days despite being on vancomycin with appropriate blood levels. Vancomycin was switched to daptomycin and ceftaroline, which cleared her cultures. Repeat TEE showed improved vegetation size. Our case highlights the rarity and management of EV endocarditis and the importance of synergy for treatment of persistent MRSA bacteraemia.