Prosthetic valve endocarditis (PVE) is an infectious disease involving prosthetic heart valves and their surrounding tissues, most commonly affecting the aortic valve. Over the past two decades, the use of bioprosthetic valves has surpassed that of mechanical valves. Transcatheter aortic valve replacement (TAVR) and other valve repair or replacement procedures (e.g., mitral, tricuspid, and pulmonary valves) have been rapidly advancing, partially or completely replacing surgical interventions. These developments have introduced new challenges in the clinical diagnosis and treatment of infective endocarditis (IE).
Patients with prosthetic valves have a 50-fold higher risk of developing IE compared to the general population. The incidence of PVE ranges from 1% to 6%, with an annual incidence of 0.3% to 1.2%. Both mechanical and bioprosthetic valves are equally susceptible. The incidence of IE associated with TAVR is 1.0% in the first year and 1.2% annually thereafter.
IE occurring within one year after valve replacement is defined as early PVE, while IE occurring after one year is defined as late PVE. The causative pathogens differ between early and late PVE: early PVE is primarily caused by Staphylococcus, Gram-negative bacilli, and fungi, whereas late PVE resembles native valve endocarditis (NVE) and is mainly caused by Staphylococcus, Streptococcus, and Enterococcus. For TAVR-related IE, the most common pathogens are Enterococcus and Staphylococcus, with Enterococcus being more prevalent.
The clinical presentation of PVE is often atypical and frequently lacks fever. Even when fever is present, it is difficult to distinguish from other common infections, particularly in the early postoperative period. Persistent fever in patients after prosthetic valve replacement raises suspicion for PVE. In such cases, all diagnostic methods used for NVE are also applicable to PVE, with transesophageal echocardiography (TEE) or CT being the most helpful for establishing a definitive diagnosis. Similarly, the ESC diagnostic criteria can be used to evaluate suspected cases.
Antibiotic treatment for PVE is similar to that for NVE but requires an extended duration of 6-8 weeks or longer. Any combination therapy should include gentamicin and rifampin. Surgical intervention for PVE should follow the general principles of NVE and must involve the removal of all infected foreign materials, including implanted prosthetic valves and any residual valve tissue from prior surgeries. For patients requiring valve re-replacement, surgery should be performed as early as possible. Indications for valve re-replacement include:
- Paravalvular leakage or valvular regurgitation causing moderate-to-severe heart failure.
- Fungal infection.
- Persistent bacteremia despite adequate antibiotic treatment.
- Acute valve obstruction.
- Instability of the prosthetic valve.
- New-onset cardiac conduction disturbances.
PVE represents the most severe form of IE, with an in-hospital mortality rate of 20%-40%. Prognosis is influenced by factors such as advanced age, diabetes, healthcare-associated infections, Staphylococcus or fungal infections, early PVE, heart failure, stroke, and intracardiac abscesses. Among these, the presence of complications and Staphylococcus infections are the strongest predictors of poor outcomes