MP-1 - SEX DIFFERENCES IN ISCHEMIC STROKE OUTCOMES AMONG YOUNG ADULTS IN ONTARIO.

Background: Stroke is a leading cause of death and disability in Canada. Stroke incidence among young adults is increasing, but whether the stroke recurrence and poor stroke outcomes vary by sex in this age group is less understood. We use Institute for Clinical Evaluative Sciences (ICES) data to compare clinical outcomes [myocardial infarction (MI), transient ischemic attack (TIA), recurrent stroke, or death from ischemic stroke] between young women and men with acute ischemic stroke.

METHODS AND RESULTS: We used administrative databases to identify community-dwelling adults (aged ≤ 50 years) residing in Ontario on January 1, 2011. We obtained sex from Ontario Registered Persons Database and stroke and prevalence of stroke risk factors from the Ontario Stroke Registry. We identified all people hospitalized with ischemic stroke between 2011 and 2014, and then measured outcomes MI, TIA, recurrent stroke, or death from ischemic stroke at 1 year follow-up from index date of stroke. We further measured composite outcomes of TIA/MI/recurrent stroke/ death from ischemic stroke at 1 year follow-up. We reported baseline differences in vascular risk factors between men and women, stratified by age (Table). We used multivariable Cox proportional hazard models to evaluate the interaction between sex and age (18-44 vs 45-50) on composite outcomes of TIA/MI/recurrent stroke.

Our study population included 2,247 adults (43.1% women, mean age 42.3±7.3) with ischemic stroke matched to same people without stroke (43.1% women, mean age 42.3±7.3). Adults aged 45-50 years had a higher risk of stroke event and outcomes (TIA/ MI/ recurrent stroke and TIA/ MI/ recurrent stroke/ death) compared to adults aged 18-44, regardless of sex. Male sex had a stronger association with MI following ischemic stroke [HR 1.5, 95% CI 1.05-2.24]. When stratified by age, men aged 45-50 years were more likely to experience composite endpoints of TIA, MI and recurrent stroke then women [HR 1.3, 95% CI 1.02-1.6]. Men were more likely to experience TIA, MI and recurrent stroke in ages 45-50 then ages 18-44 years [HR 1.3, 95% CI 1.03-1.58] (Figure).


Conclusion: Composite outcomes of TIA, MI, recurrent stroke and death from ischemic stroke were higher in men and women aged 45–50-years compared to 18-44 years at year after initial ischemic stroke, with a potentially greater influence of age on TIA, MI and stroke recurrence in men. Future work should evaluate the explanations for the differential effect of age on stroke outcomes among men and women Ontario residents with history of ischemic stroke.