Effect of aspirin on dementia and cognitive impairment in the ASCEND trial

Presented at the American Heart Association’s Scientific Sessions 2021 by: Prof. Jane Armitage - Oxford, UK.

Introduction and methods

Aim of the study

Use of low-dose aspirin once-daily reduces risk of major occlusive vascular events but at the cost of increased risk of serious bleeding. When looking at the brain, aspirin may reduce cognitive impairment by prevention of ischemic strokes and TIAs, but on the other hand may increase cognitive impairment by increased risk of intracranial bleeds and microbleeds. But this is not clear from previous randomized trials with aspirin.

Study design

This study used data of the ASCEND trial. ASCEND enrolled 15,480 diabetes patients ≥40 years without prior CVD. This study used data of the randomization to aspirin 100 mg daily or placebo. Mean follow-up was 7.4 years with an additional 1.8 years post-trial. For this study, 99% of participants were linked to electronic hospital admission records.

Primary outcome

Key outcomes were: a broad dementia outcome consisting of dementia, cognitive impairment, delirium/confusion, dementia medications, referral to memory clinic, geriatric psychiatry; a narrow dementia outcome of dementia alone; and a cognitive function z-score at final follow-up, based on either Telephone Interview for Cognitive Status (TICSm) and verbal fluency or the Healthy Minds test developed by UK Biobank. Data on dementia outcomes were obtained by hospitalizations, patients, caregivers or physicians.

Main results

• Event rate of the broad dementia outcome was 7.1% in the aspirin group and 7.8% in the placebo group (RR 0.91, 95%CI:0.81-1.02).
• Narrow dementia was not different between the two groups (RR 0.89, 95%CI:0.75-1.06).
• The cognitive z-score difference between the two groups was 0.012 (95%CI:-0.016, 0.039), a non-significant difference.

Conclusion

There was no statistically significant effect of aspirin on dementia outcomes in the ASCEND trial. Prof. Jane Armitage concluded that trials with larger number of incident dementia cases are needed to assess whether a 15-18% risk reduction with 5-7 years of aspirin use exists. Furthermore, routine electronic health data in the UK provide a cost-effective means to assess the impact of aspirin and other preventive therapies on dementia.

Discussion

The discussant Erin Michos , MD (John Hopkins, Baltimore, MD, USA) said that these results are consistent with those in the ASPREE trial in healthy older adults. An important finding of ASCEND was that participants who experienced a CV event had a 2.5 fold increased risk of dementia, indicating that CVD should be prevented in the first place by lipid and BP control and smoking cessation. As a prevention strategy for dementia, we need more focus on improving CV health of the population much earlier in life, said Michos.

• Our reporting is based on the information provided at the American Heart Association’s Scientific Sessions 2021 -

Watch a video by prof. Armitage on this study