Prognostic factors in Staphylococcus aureus endocarditis and results of therapy with a penicillin and gentamicin.

Data on 40 patients with Staphylococcus aureus endocarditis treated with appropriate antibiotics in adequate dosage at the University of Cincinnati Medical Center hospitals between January 1961 and June 1975 were analyzed. The overall mortality was 40 per cent. The mortality was 11.1 per cent in patients under 50 years old and 63.6 per cent in patients over 50 years old (p less than 0.01). Seven patients were narcotic addicts who had no underlying disease and were under 50 years old; all survived. For patients without underlying diseases, the mortality was 0 per cent in those under 50 years old and 75 per cent in those over 50 years old. Patients who died had a greater number of major underlying diseases (pre-existing cardiac disease, diabetes mellitus, alcoholism and/or cirrhosis) than the survivors. Patients over 50 years old had significantly more major underlying diseases than patients under 50 years old (p less than 0.001). Among patients over 50 years old, those who died had more complications than the survivors while the number of underlying diseases were comparable. A group of patients treated with gentamicin during the first two to three weeks of therapy in addition to a penicillin was compared to a similar group treated with a single antibiotic. The mortality of both groups was 40 per cent.