Abstract Number: Esoc2026ys151 Ischaemic Stroke in Young Adults: A Hospital-Based Study on Epidemiology and Aetiology in a Middle-Income Country

Abstract Background and aims Young-onset ischaemic stroke accounts for up to 15% of all strokes and carries a substantial long-term societal burden. This study aims to describe the epidemiological profile, vascular risk factors, and aetiological subtypes of ischaemic stroke and transient ischaemic attack in adults aged ≤55 years. Based on these findings, the study aims to develop an institutional aetiological investigation protocol for young adults, designed to optimise diagnostic yield while reducing unnecessary costs and length of hospital stay without overlooking rare but clinically relevant causes. Methods We conducted a retrospective hospital-based observational study including patients aged 18–55 years admitted with ischaemic stroke or transient ischaemic attack between 2019 and 2024. Demographic characteristics, vascular risk factors, clinical presentation, investigations, acute treatment, and outcomes were obtained from a semi-automated hospital stroke database and medical records. Stroke severity was assessed using the NIH Stroke Scale and functional status using the modified Rankin Scale. Aetiology was classified according to TOAST. Results A total of 244 patients has been analysed to date (median age 48 years; 58% men). There was a high prevalence of modifiable risk factors, frequently uncontrolled, particularly hypertension. Aetiology showed a heterogeneous pattern: other determined causes and undetermined aetiology were the most frequent categories among younger patients, whereas small- and large-vessel disease increased with advancing age. Ischaemic stroke in young adults is characterised by diverse, age-dependent aetiologies and a substantial burden of preventable vascular risk factors. Findings will support the design of cost-conscious, time-efficient, and comprehensive diagnostic protocols for this population in clinical practice. Conflict of interest Ana Beatriz Baston: nothing to disclose Figure 1 - belongs to Results