P4‐145: Aspirin in Alzheimer's Disease: Increased Risk of Intracerebral Haemorrhage and no Clinical Benefit

Risk of hemorrhagic and ischemic stroke in patients with Alzheimer disease: A synthesis of the literature

OBJECTIVE

To assess the risk of hemorrhagic and ischemic stroke in patients with Alzheimer disease (AD) compared with non-AD controls with similar risk profiles.

METHODS

A search was conducted on EMBASE and MEDLINE for reports published up to September 26, 2018. Studies were included if they (1) assessed the incidence of stroke in patients diagnosed with AD; (2) included patients with no history of stroke; and (3) reported outcomes by stroke subtype. The main outcome was relative risk of ischemic or hemorrhagic stroke. Furthermore, the rate of stroke occurrence per 1,000 person-years was assessed. A random-effects meta-analysis was undertaken. The risk of bias in included studies was assessed in terms of selection, comparability, and outcome.

RESULTS

A total of 3,605 studies were screened in the title and abstract phase after removing duplicates, and 88 eligible studies were screened for full text. Eight studies met the inclusion criteria representing 121,719 individuals (AD = 73,044; non-AD = 48,675). Five studies were included in the relative risk analysis, among which 4 studies applied formal matching criteria of 44,544 AD and 44,660 non-AD controls. The included studies were based on nationwide registries from Finland, Sweden, Taiwan (2), United Kingdom (2), 1 clinic-based study from the Netherlands, and 1 US population-based cohort. Among patients with AD, the incidence rate of hemorrhagic stroke was 3.41/1000 person-years (95% CI 2.70-4.32) and 2.23 (95% CI 1.72-2.88) among AD cases and non-AD controls, respectively. This is in contrast to 13.98 (95% CI 9.86-19.81) and 12.12 (95% CI 7.55-19.46) for ischemic stroke among AD cases and non-AD controls, respectively. Compared with non-AD controls with similar risk profiles, patients with AD had a relative risk of 1.42 (95% CI 1.23-1.64) for hemorrhagic stroke and 1.15 (95% CI 0.89-1.48) for ischemic stroke.

CONCLUSION

Compared with non-AD controls with similar risk profiles, patients with AD are likely at a higher risk of hemorrhagic but not ischemic stroke.

Aspirin for vascular dementia

BACKGROUND

For patients with a diagnosis of vascular dementia there is evidence that aspirin is widely prescribed - in one study, completed by geriatricians and psychiatrists in the UK, 80% of patients with cognitive impairment (with vascular risk factors) were prescribed aspirin. However, a number of queries remain unanswered: Is there convincing evidence that aspirin benefits patients with vascular dementia? Does aspirin affect cognition or improve prognosis? In addition, does the risk of cerebral or gastric haemorrhage outweigh any benefit? The aim of this review is to assess the evidence of effectiveness of aspirin in those with a diagnosis of vascular dementia.

OBJECTIVES

To assess the evidence of effectiveness of the use of aspirin for vascular dementia.

SEARCH STRATEGY

Computerised databases were searched independently by two reviewers. In addition, relevant websites were searched and some journals were handsearched. Specialists in the field were approached for unpublished material and also any publications found were searched for additional references.

SELECTION CRITERIA

All randomised controlled trials investigating the effect of aspirin for vascular dementia are included. Inclusion/exclusion of studies comprised systematic assessment of the quality of study design and the risk of bias.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by both reviewers, using a previously tested data extraction form and, where required, authors were contacted for data not provided in the papers. The aim was to evaluate data recorded via tools assessing cognitive and behavioural changes along with mortality, morbidity and institutionalisation data.

MAIN RESULTS

One randomised controlled trial ( approximately approximately Meyer 1989 approximately approximately ) was included, and yielded data for analysis on a total of 70 patients. The only relevant outcome assessed in this trial was cognition. Change in cognitive outcome was towards being in favour of treatment.

REVIEWER'S CONCLUSIONS

There is very limited evidence that aspirin is effective in treating patients with a diagnosis of vascular dementia. Further research is needed to assess the effect of aspirin on cognition, and also on additional outcomes such as behaviour, and quality of life. At present it is not possible to provide evidence for other queries regarding the use of aspirin for dementia (these are described in the Background section of this review).