We analyzed a prospective series of 228 cases of native valve infective endocarditis in non-intravenous drug users attending our center between 1987 and 2009. We compared three subperiods: 1987-1994 (67 cases), 1995-2002 (74 cases) and 2003-2009 (87 cases).
The mean age of patients has progressively increased (38 ± 22 years in the first subperiod vs 60 ± 16 years in the third; P < .001), as has the proportion of cases without predisposing heart disease (25 % , 46 % and 67 % ; P < .001). Incidence of mitral valve prolapse remained stable (12 % , 18 % and 11 % ). Percentages of patients with predisposing heart disease and who were aware of their condition have fallen in recent years (45 % , 27 % and 21 % ; P < .001). A portal of entry for the infection could not be identified in 64 % . Overall, Staphylococcus aureus is the most frequent causative organism (26 % ) whereas the percentage of cases caused by Streptococcus viridans remains unaltered (22 % , 20 % and 24 % ).
We found significant changes in the epidemiology of native valve infective endocarditis. The incidence of patients without predisposing heart disease has increased significantly and staphylococci are the most frequent causative organisms.