What is the recommended management for prosthetic valve endocarditis?

From the Guidelines

The recommended management for prosthetic valve endocarditis involves prompt initiation of empiric antibiotic therapy, often requiring surgical intervention, with a focus on tailored treatment based on culture results and consideration of the causative organism, as outlined in the 2015 American Heart Association guidelines 1.

Key Considerations

• Initial empiric therapy should include vancomycin (30 mg/kg per 24 hours in 2 equally divided doses) plus rifampin (900 mg per 24 hours IV or orally in 3 equally divided doses), with gentamicin (3 mg/kg per 24 hours IV or IM in 2 or 3 equally divided doses) sometimes added for the first 2 weeks, as recommended for Staphylococci infections 1.
• For Staphylococcus aureus PVE, a combination of anti-staphylococcal penicillin (or vancomycin if MRSA) with rifampin and gentamicin is recommended, based on the unique role of rifampin in sterilizing foreign bodies infected by S aureus, as noted in previous guidelines 1.
• Surgical intervention is indicated in cases with heart failure, uncontrolled infection, abscess formation, persistent bacteremia despite appropriate antibiotics, large vegetations (>10mm), or prosthetic valve dysfunction, highlighting the importance of early surgical consultation 1.
• Blood cultures should be obtained before initiating antibiotics, and transesophageal echocardiography is preferred over transthoracic for diagnosis, given its higher sensitivity for detecting prosthetic valve infections 1.

Treatment Duration and Monitoring

• Treatment duration typically lasts 6 weeks, with careful monitoring of the patient's response to therapy and adjustment of the treatment regimen as needed, based on culture results and clinical progression 1.
• The use of combination therapy, including aminoglycosides like gentamicin, is recommended for the initial 2 weeks of therapy, due to the high morbidity and mortality rates associated with staphylococcal prosthetic valve endocarditis 1.

From the Research

Prosthetic Valve Endocarditis Management

• The management of prosthetic valve endocarditis (PVE) is a complex process that often requires prolonged antimicrobial therapy with or without surgery 2.
• The use of vancomycin-intermediate Staphylococcus aureus has been reported to be challenging, but a combination of daptomycin, ceftaroline, and rifampin has been shown to be effective in treating PVE 2.
• Rifampin has been used in combination with other antibiotics, such as vancomycin or beta-lactam antibiotics, to treat PVE caused by methicillin-resistant Staphylococcus epidermidis, with a cure rate of 70% 3.
• The optimal duration of antibacterial treatment for PVE is 6 weeks, and the use of gentamicin and rifampin has been recommended as adjunctive therapy 4.
• However, recent studies have suggested that the use of gentamicin and rifampin may not be beneficial in treating staphylococcal PVE, and may even be associated with increased nephrotoxicity, hepatotoxicity, and risk of drug-drug interactions 5, 6.
• A multicenter retrospective study found that the use of rifampin was not associated with better outcomes in patients with staphylococcal PVE, and that the 1-year mortality and relapse rates were similar in patients treated with or without rifampin 6.

Treatment Strategies

• The treatment of PVE typically involves a combination of antibiotics, such as vancomycin, daptomycin, and ceftaroline, with or without the use of gentamicin and rifampin 2, 4.
• The choice of antibiotics and the duration of treatment should be individualized based on the specific pathogen, the patient's clinical condition, and the results of susceptibility testing 4.
• Surgery may be necessary in some cases, such as when there is evidence of valve dysfunction or when the infection is not responding to antibiotic therapy 2.

Controversies and Uncertainties

• The use of gentamicin and rifampin as adjunctive therapy for PVE is controversial, and recent studies have raised questions about their effectiveness and safety 5, 6.
• Further research is needed to determine the optimal treatment strategies for PVE and to resolve the uncertainties surrounding the use of gentamicin and rifampin 5, 6.