Stroke Subtypes Drive Distinct Neurological, Cognitive, and Mortality Outcomes in UK Biobank Cohort

Area of Science:

• Neurology
• Public Health
• Epidemiology

Background:

• Stroke subtypes, including acute ischemic stroke (AIS), subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), and other nontraumatic intracranial hemorrhage (ONIH), have distinct pathophysiological characteristics.
• However, their long-term associations with mortality, cognitive function, and dementia risk are not fully understood.

Purpose of the Study:

• To investigate how different stroke subtypes impact long-term survival, cognitive performance, dementia risk, and neuroimaging findings.
• To compare these outcomes across stroke subtypes and against stroke-free individuals.

Main Methods:

• Utilized UK Biobank data to analyze subtype-specific associations with mortality, dementia incidence, cognitive performance, and white matter hyperintensity (WMH) burden.
• Employed multivariable Cox proportional hazards models for survival and dementia risk, and covariate-adjusted linear models for cognitive outcomes.

Main Results:

• Mortality risk varied significantly by stroke subtype, with ICH exhibiting the highest hazard ratio (HR 7.62) compared to stroke-free individuals.
• At 5 years post-stroke, mortality rates were highest for ICH (43.5%), followed by ONIH (39.8%), SAH (30.0%), and AIS (20.0%).
• ICH was associated with the highest dementia risk, and post-stroke cognitive deficits, including slower reaction times and lower fluid intelligence, were observed across multiple subtypes, particularly AIS and ICH.

Conclusions:

• Stroke subtype is a critical determinant of distinct long-term outcomes, including mortality, dementia risk, cognitive impairment, and neuroimaging characteristics.
• These findings underscore the heterogeneity of stroke and emphasize the need for subtype-specific monitoring and prognostication strategies.