Aspirin for the prevention of cognitive decline in the Elderly: a Neuro-Vascular Imaging Study (ENVIS-ion), a sub-study of ASPirin in Reducing Events in the Elderly (ASPREE)

The ENVIS-ion trial will examine whether low dose aspirin is effective in delaying the onset of declining abilities of thinking and memory in healthy older adults. Participants in the ENVIS-ion trial will be recruited from men and women who have agreed and consented to participate in the clinical trial of low dose aspirin (the ASPREE Trial ISRCTN83772183). The main features of the ENVIS-ion trial are additional measurement of brain and retinal structures by magnetic resonance imaging (MRI) and retinal photography in each participant before starting on the study drug and after treatment with aspirin or placebo for 3 years. As a part of the ASPREE study, mental functions are assessed every year by questionnaires administered by a trained researcher. For ENVIS-ion, participants will have extra questionnaires to further test their mental abilities. MRI of brain structure will detect markers of early worsening of thinking and memory abilities. Blood vessels of the retina share many features with vessels of the brain. We will compare whether aspirin lessens changes over time of features shown with brain MRI and retinal photography and compare these with the questionnaire measurements of mental function.