[Novel clinical and epidemiologic trends in elderly infective endocarditis]

The age of peak incidence of infective endocarditis (IE) has shifted from 45 years in the 50's to 70 years at the present time. Elderly persons carry a five times higher risk of IE than the general adult population. Factors accounting for this phenomenon include increased use of invasive procedures and implanted medical devices as well as a higher prevalence of degenerative valve disease. In the elderly, IE onset may be insidious, often masked by one or more underlying conditions such as cancer, diabetes and chronic organ failure, hence the diagnosis may be delayed. The leading pathogen is Staphylococcus aureus, more frequently methicillin-resistant, although Streptococcus bovis and enterococci are gaining prevalence. Vascular phenomena and embolic events are less common in the elderly, probably due to a lessened acute phase response and a larger use of antiplatelet and anticoagulant drugs. Because of diminished renal clearance, antibiotics should be carefully titrated in aged IE patients. Cardiac surgery is performed less often in elderly IE due to poor preoperative conditions. Indeed, both these factors may account for the higher mortality rate, that is twice that of younger IE patients. Notwithstanding, age > or = 65 years has been found to be an independent predictor of mortality. Prophylactic measures residing mostly on the prevention of health-care associated acquisition need to be more widely implemented in this growing subgroup of IE patients.