Prosthetic valve endocarditis
The risk of developing prosthetic valve endocarditis (PVE) is greatest during the initial 3 months after surgery, remains high for 6 months, and then falls gradually. Infection generally occurs with equal frequency on aortic and mitral sites as well as on mechanical and bioprosthetic devices during the first postoperative year. Afterward, bioprosthetic valves have a higher risk of infection due to age-related alterations in the valves' surfaces.
PVE can be divided into early and late infection.
- Early – Microorganisms reach the prosthesis by direct contamination intraoperatively or via hematogenous spread. Common organisms, in order of decreasing frequency, are Staphylococcus aureus and coagulase-negative staphylococci, gram-negative bacilli, and fungal organisms.
- Late – Generally caused by the same pathogens as native valve infection. The usual organisms are streptococci, S. aureus, coagulase-negative staphylococci, and enterococci.
The mainstay of treatment is antibiotics that are started empirically and later tailored based on culture data. The usual choice for empiric therapy is vancomycin and gentamicin with either cefepime or a carbapenem. The common duration of antibiotic treatment is 6 weeks. Indications for surgery include persistent bacteremia or fever lasting more than 5-7 days despite appropriate antibiotic therapy, valve dysfunction causing heart failure, paravalvular abscess or fistulae, heart block, relapse after optimum medical therapy, and infection with highly resistant organisms like S. aureus, gram-negative rods, or fungi.
T82.6XXA – Infection and inflammatory reaction due to cardiac valve prosthesis, initial encounter
233853009 – Prosthetic valve endocarditis