[Bacterial endocarditis occurring on native valves: identification of risk patients].

Analysis of the large series of infective endocarditis reported in the medical literature allows identification of the principal poor prognostic factors. Of the clinical factors, the worst prognosis is observed in the most elderly patients, in those with persistence of the infections syndrome despite antibiotic therapy, those with cardiac failure or complications, principally arterial embolism (cerebral or peripheral). From the anatomical viewpoint, aortic valve endocarditis seems to carry a slightly worse prognosis than mitral valve endocarditis, but the extension of infection to the paravalvular region is the complication most likely to aggravate the condition. The infecting organism is also an important factor: non-streptococci, especially staphylococcal endocarditis, have a much worse prognosis. Finally, echocardiographic analysis of the vegetations allows identification of the cases with the highest risk of embolism: those with vegetations over 10 mm in size which appear very mobile. The appearance of signs of poor haemodynamic tolerance, the persistence of an infectious syndrome despite appropriate medical therapy and the detection of large, mobile vegetations by echocardiography should lead to early surgical referral: this attitude now provides good immediate and long-term results.