Abstract WP223: Evolution of Ischemic Stroke Subtypes: An Observational Study Over 15 Years

Abstract

Introduction: In the face of population ageing and contemporary cardiovascular risk factor control, understanding the evolution of ischemic stroke mechanisms may inform stroke prevention strategy and guide resources allocation. Method: Through a registry-based observational study in a regional hospital in Hong Kong, we studied the evolution of stroke mechanisms by TOAST classification over a 15-year period (2004-2018). We retrieved demographic data, pre-defined cardiovascular risks, use of medications, intensity of risk factor control and clinical outcomes (2-year recurrence and 3-month mortality and disability) from the stroke registry. We defined stroke mechanisms by clinical signs and symptoms, cardiovascular risk profile and infarct topography. We compared the trends of stroke mechanisms by Chi-square test for trend and continuous variables by one-way ANOVA test with post-hoc Bonferroni test. Interobserver reliability was assessed by kappa statistics. Results: We included 5982 patients over the 15-year period. The number of atrial fibrillation (AF)-related stroke increased by 213% (p<0.001) and large-artery-disease (LAD)-related stroke decreased by 47.7% (p<0.001). AF-related stroke had the highest mean age (77.4±11, p<0.001) and National Institute of Health Stroke Scale on admission (14.8±10.8, p<0.001). Within the AF-related stroke patients, the number of strokes as first presentation of AF increased by 200%. 2-year recurrence of stroke or transient ischemic attack of patients with symptomatic intracranial atherosclerosis (ICAS) decreased from 20.7% to 9.3%. Conclusion: We observed a huge increase in AF-related stroke and newly diagnosed AF at presentation. Our results demanded an enhanced surveillance in detecting AF, primary prevention and thrombectomy facilities given the high morbidity and mortality associated with AF-related strokes. The decline in ICAS-related stroke and its recurrence may underscore the importance of intensive risk factor management in the Asia-Pacific region where ICAS remained prevalent.