ABSTRACT NUMBER: ESOC2026A2126 ETIOLOGIC SPECTRUM AND RISK FACTOR PROFILES OF ISCHEMIC STROKE IN YOUNG ADULTS: AN AGE- AND SEX-SPECIFIC ANALYSIS FROM SAUDI ARABIA

Abstract Background and aims Ischemic stroke in young adults is heterogeneous with distinct etiologies and long-term consequences. In Saudi Arabia, where the population is predominantly young, data on stroke mechanisms in this age group are limited. Identifying age- and sex-specific patterns is essential to guide diagnostic evaluation and secondary prevention. Methods We conducted a retrospective cohort study at King Faisal Specialist Hospital and Research Centre, Riyadh, including patients aged 18–55 years with confirmed ischemic stroke between January 2010 and May 2024. Demographic data, vascular risk factors, clinical characteristics, imaging, and laboratory findings were collected. Stroke etiology was classified using standard criteria, with comparisons by age (<35 vs. ≥35 years) and sex. Results A total of 366 patients were included; 68.3% were male. Mean age was 42.4 ± 8.9 years, with females presenting younger than males (39.5 vs. 43.8 years; p < 0.001). Traditional vascular risk factors were significantly more prevalent in patients aged ≥35 years. Large artery atherosclerosis (34.2%) and cardioembolism (31.7%) were the most common etiologies, followed by small vessel disease (10.9%). Other determined causes included pregnancy-related stroke, autoimmune disease, hyperhomocysteinemia, Sneddon syndrome, and HIV. Cardioembolic mechanisms varied by age and sex. Hypercoagulable states were identified in 7.9% of patients, with genetic thrombophilia more frequent in younger individuals. Conclusions Young adults with ischemic stroke in Saudi Arabia exhibit distinct age and sex-related etiologic patterns, with a substantial burden of atherosclerotic and cardioembolic disease. Selective use of thrombophilia and genetic testing may enhance diagnostic yield and inform tailored prevention strategies. Conflict of interest Mohammed Alkhudhair: nothing to disclose