From the Guidelines
Prosthetic valve endocarditis (PVE) is a serious infection that requires prompt diagnosis and aggressive treatment, with a recommended initial management including blood cultures and empiric antibiotic therapy, adjusted based on culture results, and often necessitating surgical intervention. The management of PVE involves a multidisciplinary approach, including cardiologists, cardiac surgeons, microbiologists, and intensivists 1.
Diagnosis and Treatment
The diagnosis of PVE rests on the combination of positive blood cultures and echocardiographic evidence of prosthetic infection, including vegetations, paraprosthetic abscesses, or a new paraprosthetic leak, with transoesophageal echocardiography being essential due to its greater sensitivity in detecting these abnormalities 1. Treatment duration is typically 6 weeks of intravenous antibiotics, with the specific regimen depending on the causative organism, such as Staphylococcus species in early PVE or Streptococcus, Enterococcus, or fungi in late PVE 1.
Surgical Intervention
Surgical intervention is often necessary, particularly with valve dysfunction, heart failure, persistent bacteremia despite appropriate antibiotics, large vegetations (>10mm), or abscess formation, and the timing of surgical treatment should be individualized, taking into account co-morbidities, the infecting organism, the risks of surgery, the degree of cardiac decompensation, and the extent to which infection can be controlled 1.
Prevention and Mortality
Prevention includes appropriate antibiotic prophylaxis before dental procedures in high-risk patients with prosthetic valves, and PVE carries a mortality rate of 20-40%, with worse outcomes in early-onset cases, highlighting the importance of rapid diagnosis and treatment 1.
Key Considerations
Key considerations in the management of PVE include the need for a high index of suspicion, particularly in patients at higher risk, the importance of early and effective treatment in reducing mortality, and the role of surgical intervention in maximizing outcomes, especially in cases caused by Staphylococcus aureus 1.
Recent Guidelines
Recent guidelines emphasize the importance of individualized treatment approaches, taking into account the specific characteristics of the patient and the infecting organism, and highlight the need for further research into the optimal management of PVE, particularly with regards to the role of surgical intervention and the most effective antibiotic regimens 1.
From the FDA Drug Label
Vancomycin Hydrochloride for Injection, USP has been used successfully in combination with either rifampin, an aminoglycoside, or both in early-onset prosthetic valve endocarditis caused by S. epidermidis or diphtheroids.
Vancomycin can be used for the treatment of prosthetic valve endocarditis, specifically in early-onset cases caused by S. epidermidis or diphtheroids, in combination with other antibiotics such as rifampin or an aminoglycoside 2.
From the Research
Prosthetic Valve Endocarditis Overview
- Prosthetic valve endocarditis is associated with high mortality and morbidity 3
- The infection can spread into paravalvular structures, producing abscess, and systemic embolization of infected material may cause metastatic abscess 3
Treatment Strategies
- Adjunctive surgical therapy is often necessary, in addition to antibiotics, to optimize clinical results 3
- Radical resection of all infected material and reconstruction of the heart and annuli with fresh autologous or glutaraldehyde-fixed bovine pericardium may offer the best chance to eradicate the infection 3
- Prolonged antibiotic therapy is also necessary in these patients 3
- The use of aminoglycosides for the treatment of endocarditis has been dramatically reduced over the last 20 years, and should be administered once daily, and no longer than 2 weeks 4
- For staphylococcal prosthetic-valve endocarditis, treatment with anti-staphylococcal penicillins, vancomycin, gentamicin, and rifampin may be effective 4, 5
Role of Rifampin and Gentamicin
- The addition of rifampin to vancomycin regimens resulted in an increase in serum bactericidal activity and improved cure rates in patients with prosthetic valve endocarditis caused by methicillin-resistant Staphylococcus epidermidis 5
- However, a systematic review and meta-analysis found that the existing clinical data do not suggest a benefit of either adjunctive gentamicin or rifampin in staphylococcal prosthetic valve endocarditis, and may be associated with increased risk of nephrotoxicity, hepatotoxicity, and drug-drug interactions 6
Prevention Strategies
- Prosthetic valve endocarditis is an important cause of morbidity and mortality associated with heart valve replacement surgery, and prevention is crucial 7
- Scrupulous asepsis and prophylactic perioperative antibiotic therapy are the only means of preventing prosthetic valve endocarditis at present 7
- Understanding of biofilms appears to be pivotal to the development of a successful approach to preventing prosthetic valve endocarditis 7