Factors influencing mortality from infective endocarditis in two district general hospitals.

Factors influencing mortality were studied in 92 consecutive cases of infective endocarditis admitted to two district general hospitals between January 1975 and April 1982. Thirty two patients died, an overall mortality of 35%, 13 patients died before diagnosis and 19 despite aggressive antimicrobial therapy. Bactericidal antibiotic levels were monitored in 39 cases but these did not appear to influence outcome. Mortality was lowest for Streptococcus viridans infection (15%) but rose to 50% for infections with S. faecalis and other less common organisms. Most deaths were in patients over 50. Cardiac failure on admission was a poor predictor of mortality, although this was the principal cause of death during treatment (14 cases). Eight patients had emergency valve replacement and 3 died post-operatively. When the diagnosis was missed during life (13 cases) arterial embolus was a common presenting feature (46%). Classical signs of endocarditis, other than pyrexia, were absent. A cardiac murmur (always mitral incompetence) was noted in only 6 cases and considered to be insignificant.