# From Dental Procedures to Endocarditis: Cardiobacterium hominis Infection of a Bioprosthetic Mitral Valve

## TL;DR

A 67-year-old man with a bioprosthetic mitral valve developed a rare infection after a dental procedure, highlighting the need for antibiotic prophylaxis and timely diagnosis.

## Contribution

This case report highlights the rare occurrence of Cardiobacterium hominis causing subacute endocarditis in a bioprosthetic valve patient.

## Key findings

- C. hominis was identified as the causative agent of subacute endocarditis following a dental procedure.
- The patient required redo mitral valve replacement and six weeks of IV ceftriaxone for recovery.
- The case emphasizes the importance of prophylactic antibiotics and timely diagnosis in high-risk patients.

## Abstract

Prosthetic valve endocarditis (PVE) is an extremely rare but serious complication in patients with bioprosthetic heart valves following procedures such as dental work, especially when prophylactic antibiotics are not administered. We present the case of a 67-year-old male with a bioprosthetic mitral heart valve who developed subacute endocarditis caused by Cardiobacterium hominis after undergoing a dental procedure without antibiotic prophylaxis. The patient presented to the emergency department with a six-month history of worsening fatigue, weakness, intermittent fevers, and lower extremity edema. Initial evaluation with a transthoracic echocardiogram suggested infective endocarditis. A follow-up transesophageal echocardiogram confirmed bioprosthetic mitral valve endocarditis with large vegetations and paravalvular regurgitation. While admitted, blood cultures obtained from the patient's primary care physician did come back positive for C. hominis, confirming the diagnosis of C. hominis subacute endocarditis. During the patient's hospitalization, the patient developed multiple sequelae, including septic emboli to the spleen and significant anemia due to macroangiopathic hemolysis. The patient was discharged after initiation of intravenous (IV) ceftriaxone and underwent redo mitral valve replacement. He had a successful postoperative recovery and continued IV ceftriaxone for six weeks. This case highlights the diagnostic challenges of rare pathogens in PVE, particularly C. hominis, and emphasizes the importance of timely diagnosis, appropriate antibiotic therapy, and prophylactic antibiotics for high-risk patients undergoing invasive procedures.