Abstract TP112: Stroke In The Young: Etiologies and Hospital Outcomes in a National Cohort

Introduction: Stroke in the young (SITY) is an increasingly important subtype of acute ischemic stroke (AIS). These patients tend to have fewer traditional risk factors and a lower likelihood of conventional stroke etiologies. However, the prevalence of specific stroke etiologies and outcomes in SITY remains poorly understood. Therefore, we aimed to (1) determine the prevalence of stroke etiologies and (2) characterize in-hospital outcomes in SITY. Methods: We conducted a large retrospective study using the 2022 National Inpatient Sample, a stratified national hospital discharge database. All adult AIS patients were identified and stratified into two groups (18–50 and >50 yrs). Presumed stroke etiologies were identified using ICD codes and weighted prevalence was determined using NIS-derived discharge weights. Risk factors, acute treatments, and outcomes were compared. Results: Of 689,594 adult AIS discharges in 2022, 9.3% (64,110) were for SITY. While most risk factors were lower in SITY (hypertension 64.8 vs 85.7%, hyperlipidemia 38.8 vs 61.8% and diabetes 31.3 vs 41.2%, p<0.01), SITY had higher rates of smoking (31.0 vs 17.2%, p<0.01) and obesity (27.1 vs 15.4%, p<0.01). The most likely stroke etiologies in SITY were extracranial atherosclerosis (9.6%), small vessel disease (9.2%), and congenital heart disease (8.1%). Traditional stroke etiologies were less common in SITY including atrial fibrillation (5.5 vs 27.2%, p< 0.01), large artery atherosclerosis (16.9 vs 28.5%, p< 0.01), and small vessel disease (9.2 vs 10.5%, p<0.01). Atypical stroke etiologies were more common in SITY including arterial dissection (5.5 vs 0.9%, p<0.01), hypercoagulable states (6.8 vs 2.7%, p<0.01) and endocarditis (3.6 vs 1.3%, p<0.01). SITY were more likely to receive intravenous thrombolysis (13.6 vs 9.6%, p<0.01) although had similar rates of mechanical thrombectomy (7.0 vs 6.6%). SITY had longer hospital stays (9.5 vs 7.6 days, p<0.01), lower in-hospital mortality (6.3 vs 7.9%, p<0.01) and more complications (cerebral herniation 5.7 vs 2.3%, p<0.01, and mechanical ventilation 15.0 vs 9.5%, p<0.01). Conclusions: SITY accounts for 1 in 11 AIS discharges and represents a distinct clinical entity characterized by unique risk factors and a diverse range of atypical etiologies.SITY are twice as likely to be smokers and obese. Recognizing the unique stroke etiologies in SITY will help optimize secondary stroke prevention leading to fewer recurrent strokes in this growing population.