Clinical and bacteriological characteristics of infective endocarditis in the elderly

OBJECTIVE: To determine the clinical and bacteriological features of infective endocarditis in the elderly. DESIGN: Prospective case series. SETTING: A university hospital that is both a referral and a primary care centre. PATIENTS: 114 consecutive patients treated for infective endocarditis from November 1990 to December 1993: 25 were > 70 years of age (group 1) and 89 were < 70 years old (group 2). RESULTS: Location of infective endocarditis, clinical signs, and symptoms were similar in the two groups, except for a lower occurrence of embolic episodes in the elderly (group 1:8%, group 2: 28%; P < 0.04). A higher rate of infective endocarditis on intracardiac prosthetic devices was noted in group 1 (group 1: 52%, group 2: 25%; P < 0.05). The distribution of causative micro-organisms showed a higher proportion of bacteria from the gastrointestinal tract in the elderly (group D streptococci and enterococci: 48% in group 1 v 20% in group 2) and the presumed portal of entry was more often digestive (group 1: 50%, group 2: 17%; P = 0.01). Elderly patients were less often operated on (group 1: 24%, group 2: 43%; P = 0.07) and their mortality rate was higher (group 1: 28%, group 2: 13%; P = 0.08). CONCLUSIONS: Infective endocarditis in patients over 70 often occurs in those with intracardiac prosthetic devices and is more often due to bacteria from the gastrointestinal tract. Its prognosis appears to be worse than in younger subjects.