Impact of cognitive decline on long-term stroke outcomes

Takeaway

• During the first three months after stroke, approximately one in three stroke survivors either cognitively improved, deteriorated, or remained the same.
• Early deterioration in cognitive function within the first three months after stroke was strongly associated with poor stroke outcomes.

• Findings highlight that cognitive functions of patients with stroke should be closely monitored to improve stroke outcomes especially during the first three months.

Study design

• This study included 6504 patients with first-ever strokes (mean age of 73 years) using population-based data from the South London Stroke Register between 1995 and 2018.
• Five-year outcomes of patients with cognitive deficits within the first three months after stroke were assessed.
• Funding: None disclosed.

• Of 6504 patients with stroke, 1891 patients had cognitive function measured at both 7 days and 3 months.
• Of these 1891 patients, 37% showed about 10% improvement, 30% showed 10% deterioration and 33% showed no changes in cognitive function.
• Post-stroke cognitive impairment was associated with an increased risk of:
  • mortality (adjusted relative risk [aRR], 1.8 [95% CI, 1.4-2.3] and aRR, 1.3 [95% CI, 1.1-1.5] at 1 and 5 years respectively);
  • dependency (aRR, 1.9 [95% CI, 1.4-2.7] and aRR, 1.9 [95% CI, 1.3-2.6]);
  • depression (aRR, 1.4 [95% CI, 1.0-2.0] and aRR, 1.6 [95% CI, 1.1-2.4]); and
  • being institutionalised (aRR, 2.1 [95% CI, 1.6-2.8] and aRR, 1.5 [95% CI, 1.1-2.3]).
• Compared with stable cognitive function, deterioration in cognitive function by 10% or more between 7 days and 3 months was associated with an increased risk of:
  • mortality (aRR, 1.8; 95% CI, 1.1-3.0);
  • dependency (aRR, 1.7; 95% CI, 1.2-2.4); and
  • being institutionalised after 1 year (aRR, 2.0; 95% CI, 1.3-3.2).

• Possibility of unmeasured confounding.
• Risk of bias.