Infective endocarditis (IE) is associated with high morbidity and mortality. However, the impact of geriatric syndromes on clinical outcomes in elderly patients with IE remains insufficiently characterized. The aim was to assess the prevalence of geriatric syndromes; focusing on frailty, functional dependence, comorbidity and malnutrition; and their association with in-hospital mortality in advanced-age patients with infective endocarditis.

This prospective multicenter observational registry included patients aged ≥ 75 years with possible or definitive IE. Comprehensive geriatric assessment was performed after IE diagnosis using the Clinical Frailty Scale (CFS), FRAIL scale, Mini Nutritional Assessment Short Form (MNA-SF), Barthel index, and age-adjusted Charlson comorbidity index. Patients were classified as frail (CFS ≥ 4) or non-frail (CFS < 4).

Among 115 patients (median age 81 [78–85] years, 70.4% male), 52 (45.2%) were classified as frail. Despite similar surgical indications, frail patients underwent surgery less frequently than non-frail patients (10 (19.2%) vs. 30 (47.6%), P = 0.001) and presented higher in-hospital mortality (19 (36.5%) vs. 10 (15.9%), P = 0.011). Multivariate analysis identified malnutrition risk (MNA-SF: OR = 0.712, 95% CI: 0.516–0.983, P = 0.039) and comorbidity (adjusted Charlson: OR = 1.623, 95% CI: 1.108–2.379, P = 0.013) as independent predictors of in-hospital mortality. Frailty was significantly associated with mortality in a separate model excluding malnutrition, suggesting overlap between both constructs.

Geriatric syndromes, particularly comorbidity and malnutrition, are highly prevalent in elderly patients with IE and independently predict in-hospital mortality. Comprehensive geriatric assessment should be integrated into clinical decision-making for this population.