Some studies have demonstrated that in infective endocar-ditis (IE) older age is associated with a higher mortality rate[1, 2], higher frequency of mitral-valve involvement [3],renal failure, and cerebral embolism [4]. In the studypresented here, we aimed to analyze the clinical features ofIE and to delineate short- and long-term outcome of IE inchildren, young adults and elderly patients. Charts of allpatients definitively diagnosed with IE from January 1987through December 1996 were identified (n=228) andgrouped according to age: group I included patients aged1–15 years; group II, patients aged 16–40 years; group III,patients aged 41–60 years; and group IV, patients aged≥61 years. For each patient, data on demographics, clinicalfeatures, and outcome were collected. Statistical analyseswere performed using ANOVA, chi-square, and Coxregression for multivariable analysis of survival (SPSSCorporation, Chicago, IL, USA).None of the 228 patients analyzed had a history ofintravenous drug abuse. There were 13 patients in group I,25 in group II, 57 in group III, and 133 in group IV. Nosignificant differences in clinical symptoms, rate of surgicalintervention, and length of hospitalization were foundamong the groups (Table 1). As expected, congenital heartanomalies were common (62%) in group I, while native-valve involvement (rheumatic and degenerative heartdisease) was more frequent in the other groups (40% ingroup II and 47% in groups III and IV; p=0.001).Prosthetic-valve IE occurred more commonly in groups IIand III (36 and 32%, respectively) than in groups I (8%)and IV (16%) (p<0.001). The mitral valve was involvedmost frequently in all groups, while the aortic valve wasinvolved in 41.7 and 41.4% of cases in groups II and IV,respectively (p=NS). Blood cultures were positive in 87%of the patients.In group I, the most commonly involved and evenlydistributed microorganisms were viridans streptococci,coagulase-negative staphylococci, and gram-negativebacilli (23% for each). Gram-negative organisms (Haemo-philus influenzae, Escherichia coli, Brucella melitensis,Klebsiella pneumoniae, and Bacteroides spp) were morecommonly involved in group I compared with the othergroups (23 vs 2–5% in other groups; p=0.014; Table 1).Viridans streptococci were the microorganisms isolatedmost commonly in groups III and IV, whereas Staphylo-coccus aureus was the most frequent in group II (44%,Table 1). The percentage of patients with S. aureusendocarditis was similar in patients with IE of prostheticvalves (35%) and native valves (29%) (p=0.364).Urea levels increased significantly with age (p=0.002),while total bilirubin was inversely related to age (r=−0.181, p=0.0001). No significant differences in echocar-diographic findings were observed among the groups.Mean survival rates were 102.5±79.9 months in group I,101.9±74.5 in group II, 95.7±74.5 in group III, and 55.5±52.0 months in group IV (p=0.001). Surprisingly, in-hospital mortality rates were similar in all groups despitethe age differences (17, 13, 9 and 12% in groups I, II, IIIand IV, respectively; p=0.844; Table 1). Significantpredictors of in-hospital mortality according to univariateanalysis were hypoalbuminemia (3.1±0.8 g% vs 3.7±0.5;