[Survey of infective endocarditis in the last 10 years: analysis of clinical, microbiological and therapeutic features].

Infective endocarditis still presents problems with early diagnosis, selection of antibiotics and timing of surgical procedure despite modern antibiotics and investigative procedures. A retrospective study was performed to clarify the clinical and microbiological spectrum of recent infective endocarditis in the Japanese population in 38 patients with infective endocarditis (mean age 42.7 +/- 12.5 years) treated from March 1986 to March 1996. The portal of entry to bacteremia was unknown in most cases (57.9%), but the commonest identified portal was dental procedure (18.4%). Overall, the aortic valve was infected most frequently (44.7%) and followed by the mitral valve (36.8%). The most common complication of infective endocarditis were emboli (11/38, 28.9%) and congestive heart failure, NYHA class III and IV (14/38, 36.8%). Organisms were isolated from 26 of the 38 (68.4%) patients. Streptococcus viridans was the most frequent organism (34.2%), and then Staphylococcus aureus (13.2%). The blood culture positivity of microorganism was significantly higher in patients not receiving antibiotics than in those the received antibiotics (87.5% vs 50%, p < 0.05). The prevalence of streptococcal endocarditis decreased in the 1990s (1992-1996) in comparison with those in the 1980s (1986-1988). Multiple antibiotics were used frequently in 1990s and the sensitivity titer to piperacillin reduced from 3.0 in the 1980s to 1.8 in the 1990s. In contrast to reduction of streptococcal endocarditis, Staphylococcus aureus endocarditis has increased recently from 12.5% to 30.8%. The most common clinical features are valve destruction, low sensitivity of penicillin, and significantly higher in-hospital mortality. Surgical treatment was indicated most commonly in cases of uncontrollable heart failure, and infected valves were replaced during the active stage in 11/23 cases (47.8%). In-hospital mortality was higher in the medical treatment group than in the surgical group, but a long-term mortality of mean observation term 4.2 +/- 3.2 years was identical in the chronic phase. In patients with infective endocarditis and successful treatment in the acute stage, a long-term survival rate in medically treated patients was found almost comparable to surgically treated patients in our series. However, it should be emphasized that streptococcal endocarditis is being replaced by infection by Staphylococcus aureus, which is resistant to penicillin and requires intensive chemotherapy and proper decision at suitable timing for surgical therapy in the early stage.