Background: There is limited data concerning recurrence of ischemic stroke (IS) and mortality in young adults. Furthermore, it remains unclear whether the outcome differs between etiological subgroups, including IS of undetermined etiology.
Methods: Since 2001-02, consecutive individuals hospitalised for IS have been prospectively registered in a single-center database and followed-up clinically. Clinical data, investigation results, stroke etiology, treatments and outcomes are prospectively recorded. Cases of IS aged 18-50 were included and recurrent IS and all-cause mortality outcomes were compared between etiological subgroups. The TOAST classification was used but we considered arterial dissection and isolated patent foramen ovale (iPFO) as separate subgroups.
Results: We identified 450 individuals with IS aged 18-50. Etiology was determined in 360/450 (80%) and remained undetermined in 90/450 (20%) despite investigation by brain imaging (90/90, 100%), echocardiography (85/90, 94%), Holter (64/90, 71%), large artery imaging (83/90, 92%), and prothrombotic work-up (85/90, 94%). Median follow-up duration was 41 months. Recurrence rate by subgroup was: large-artery atherosclerosis (10/38, 26%), cardioembolism (13/83, 16%), small-vessel occlusion (5/35, 14%), arterial dissection (8/61, 13%), iPFO (7/53, 13%), other determined causes (26/90, 29%) and undetermined etiology (15/90, 17%). IS recurrence rate did not differ between etiological categories (p_0.08). Mortality rate was 9/360 (2.5%) for determined etiologies and 3/90 (3.3%) for undetermined etiology (p_0.71). Survival analysis showed no significant difference between determined and undetermined etiologies for recurrent IS (HR_0.88; 95%CI_0.51-1.51) or mortality (HR_1.46; 95%CI_0.34-6.26).
Conclusions: Recurrent IS and death affect a substantial proportion of young adults with IS, but are not predicted by the main IS etiological categories.