Delirium and subsyndromal delirium are associated with the long-term risk of death after ischaemic stroke

Background Post-stroke delirium has a negative impact on functional outcome. We explored if there is any association between delirium, subsyndromal delirium and long-term mortality after ischaemic stroke and transient ischaemic attack. Methods We included 564 patients with ischaemic stroke or transient ischaemic attack. We assessed symptoms of delirium during the first 7 days after admission. We used Cox proportional hazards models to analyse all-cause mortality during the first 5 years after stroke. Results We diagnosed delirium in 23.4% and subsyndromal delirium in 10.3% of patients. During the follow-up, 72.7% of patients with delirium, 51.7% of patients with subsyndromal delirium and 22.7% of patients without delirious symptoms died (P < 0.001). Patients with subsyndromal delirium and delirium had higher risk of death in the multivariate analysis (HR 1.72, 95% CI 1.11-2.68, P = 0.016 and HR 3.30, 95% CI 2.29-4.76, P < 0.001, respectively). Conclusions Post-stroke delirium is associated with long-term mortality. Patients with subsyndromal delirium are at the intermediate risk of death.