Recurrent ischaemic stroke in young adults: a multi-centre cohort study, systematic review and meta-analysis

Background Recurrent ischemic stroke (IS) disproportionately affects individuals in their most productive years, contributing to significant morbidity and mortality. Despite its growing importance, data on this critical population remain limited. Aims To characterise rates and factors associated with recurrent ischaemic stroke in young adults. Methods We performed a retrospective multicentre cohort study of consecutive acute IS patients aged 18-50 years from three tertiary hospitals in Singapore and Christchurch, New Zealand. We characterised rates and prognostic factors associated with recurrent IS over 1-year follow up using univariate and multivariable Cox Proportional Hazards models. We then performed a systematic review and meta-analysis of PubMed, Embase, Scopus and Cochrane databases for all studies from January 2000 to July 2024 evaluating recurrent stroke or transient ischaemic attack (TIA) following an index IS or TIA. We meta-analysed rates and factors associated with recurrent cerebrovascular events based on aggregate count, aggregate survival, and individual patient-level survival data reconstructed from Kaplan-Meier curves. Results The cohort study of 845 patients showed a 3.41% (95%CI 2.16-4.64) recurrence rate over 1-year follow-up. Patients with diabetes mellitus and prior stroke/TIA had significantly higher rates of recurrent IS. The systematic review and meta-analysis of 18,955 patients across 31 studies yielded a recurrence rate of 4.5-7.3% at 1 year, 10.5-12.8% at 5 years and 14.0-20.3% at >10 years. Large Artery Atherosclerosis (LAA) aetiology, hypertension, diabetes mellitus, and prior stroke/TIA were significantly associated with recurrent stroke or TIA. Conclusions Young adults with IS face a long-term risk of recurrent cerebrovascular events. More prospective studies are warranted to better characterise long-term prognosis for these patients.