Prosthetic valve endocarditis.

During 1965 to 1982, 32 episodes of infective endocarditis on prosthetic valves in 30 patients were treated at this hospital. In early endocarditis (presenting within four months of operation) staphylococci were the organisms most commonly responsible. Early endocarditis appears to be declining in incidence and is largely preventable; sternal sepsis was the main predisposing factor, requiring urgent and effective treatment. Streptococci were the most common organisms in late onset disease, but as with natural valve endocarditis a wide range or organisms was responsible. All but one of the patients with early onset disease were treated conservatively, but mortality was high; prompt surgical replacement of infected prostheses is probably indicated in such patients. Medical management was effective in most patients with late onset disease, and for them early surgical intervention may not be justified.