Variations in clinical characteristics and outcomes of infective endocarditis across age groups

Background Both the life expectancy and the global incidence of infective endocarditis (IE) among patients of 80 years and older have increased in the past decades. Diagnosis and management of IE among these elderly patients can be more challenging due to comorbid disease and frailty. Purpose To investigate clinical characteristics, management and outcome of elderly patients with IE, with specific attention to patients ≥80 years of age. Methods We included all patients with definite or possible IE discussed in our endocarditis team between 2016 and 2025. The cohort was divided into three groups based on age: group 1 (<65 years), group 2 (65-79 years), and group 3 (≥80 years). Survival was visualized with Kaplan Meier and compared using a log-rank test. Survival compared to the general Dutch population (GDP) was performed using a patient-level matching strategy. Results Of the 1042 patients discussed in our endocarditis team, 864 had definite/possible IE, with no significant differences between groups (p=0.19). Group 1 consisted of 348 patients, group 2 of 398 patients, and group 3 of 118 patients. The median age was 53 [42- 60] in group 1, 73 [69-76] in group 2, and 83 [81-85] in group 3. The proportion of female patients was significantly larger in group 3 (p=0.004, table 1). Both comorbidity and predisposing conditions for IE (p=0.005) were more often observed in group 2 and 3 compared to group 1 (table 1). Positive blood cultures were also more often present in group 2 and 3 compared to group 1 (p=0.03). There was no difference in positive imaging findings for IE (p=0.36). S. bovis and E. faecalis/faecium more often were the causative pathogen in group 2 and 3 compared to group 1. The proportion of those patients with a medical history of gastrointestinal pathology, additional testing for gastrointestinal pathology after positive blood cultures, or positive results (i.e., polyps or malignancy) of additional testing (61.8% in the total cohort) were not different between the age groups. An indication for surgery was less often present in group 3 compared to group 1 and 2 (p<0.001). In addition, the patients in group 3 with an indication for surgery were less often operated on (p=0.003), with high risk/frailty being the most important reason to withhold surgery. Survival was significantly worse in group 2 and 3, and survival relative to that of the GDP in was lowest in group 3 (figure 1). Conclusion Elderly patients had more comorbid disease and predisposing conditions for IE. There were more positive blood cultures among elderly, and S. bovis and E. faecalis/faecium more often being the causative pathogen in this group. However, evidence of gastrointestinal pathology was not different between the groups. Elderly less often had an indication for surgery, and when there was an indication, they were less often operated on. This might have contributed to the worse survival.Figure 1Table 1