Changing Epidemiology of Native Valve Infective Endocarditis

Abstract

Introduction and objectives The aim of our study is to assess changes in the epidemiologic features of patients with native valve infective endocarditis. Methods 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). Results 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%). Conclusions 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.