Stroke–heart syndrome and risk of incident dementia among patients with first‐ever ischemic stroke: A territory‐wide population‐based cohort study

INTRODUCTION The risk of dementia in patients with ischemic stroke and early cardiovascular complications (i.e., stroke–heart syndrome [SHS]) remains underexplored. METHODS Patients with first‐ever ischemic stroke in Hong Kong between 2005 and 2020 were included. Multivariable Fine–Gray competing risk analysis was performed after 1:1 propensity score matching to evaluate the association between SHS and the risk of dementia. RESULTS Of the 130,605 included patients with ischemic stroke, 12,696 (9.7%) patients developed SHS. Patients with SHS had a 19% increased risk of dementia compared to those without SHS at 1 year post‐stroke, driven mainly by vascular dementia. This increased risk gradually declined and became non‐significant after 3 years post‐stroke. Appropriate antithrombotic therapy and comorbidities optimization were associated with a 32% reduced dementia risk in patients with SHS. DISCUSSION SHS is associated with an increased risk of incident dementia. Appropriate antithrombotic therapy and comorbidities optimization post‐stroke may reduce this heightened risk of cognitive impairment. Highlights Association between stroke–heart syndrome (SHS) and dementia was evaluated in a population‐based cohort. Development of SHS associated with a 19% increased 1 year risk of dementia. The increased risk of dementia gradually declined with each year of follow‐up. Integrated post‐stroke management may reduce this heightened risk of cognitive impairment.