Young Adults with Ischemic Stroke in Argentina: A National Multicenter Retrospective Registry Analysis (JACARANDA)

Background: Young adults account for up to 15% of all ischemic strokes, yet data from Latin America remain scarce. Understanding their clinical profile and outcomes is essential to inform targeted interventions and public health strategies. We aimed to characterize demographics, vascular risk factors, stroke etiology, access to acute reperfusion therapies, and 90-day outcomes in Argentine patients aged 18–50 years with ischemic stroke. Methods: We conducted a retrospective multicenter cohort study including consecutive patients aged 18–50 years with ischemic stroke, enrolled between January 2015 and December 2023 across 26 centers in Argentina. Primary outcomes were functional dependence (modified Rankin Scale [mRS] 3–5), stroke recurrence, and all-cause mortality at 90 days. Results: Among 18934 ischemic stroke patients, 1,422 (7.5%) were young adults. Median age was 43 years (IQR 36–47), and 53.7% (n = 763) were male. The most prevalent risk factors were hypertension (31.0% [n = 441]), smoking (29.3% [n = 417]), and obesity (18.8% [ n = 267]). Median NIHSS on admission was 3 (IQR 1–8). Acute reperfusion therapy was administered in 18.9% (n = 269). Stroke etiology remained undetermined in 50.4% (n = 717) of cases; within this group, 26.1% (n = 312) fulfilled criteria for ESUS and 17.8% (n = 198) were cryptogenic strokes associated with patent foramen ovale. Arterial dissection accounted for 56.6% (n = 193) of other determined causes. At 90 days, functional dependence was observed in 12.1% (n = 110), stroke recurrence in 3.9% (n = 37), and mortality in 4.8% (n = 44). Conclusions: In Argentina, nearly 1 in 13 ischemic strokes occurs in young adults. Despite generally mild presentations, functional dependence and mortality remain substantial. The high rate of undetermined etiology underscores the need for standardized diagnostic protocols in this population, whose strokes carry a disproportionate individual and societal burden due to their early onset.