ENVISION Study

Aspirin for the prevention of cognitive decline in the Elderly: a Neuro-Vascular Imaging Study

In 2007 a collaborative group of researchers from Monash University, Canberra Hospital and the Centre for Eye Research Australia was successful in gaining NHMRC support for the ENVISion study: a sub-study of ASPREE. 

The ENVISion study aims to examine whether regular low-dose aspirin reduces the rate of increase of brain MRI-based White Matter Hyperintensity (WMH) and Silent Brain Infarction (SBI) volumes in healthy elderly Australians of both genders.  This sub-study will be carried out in 600 people who have consented to take part in, and who are suitable for, randomisation in the ASPREE study, with 300 of the sub-study participants recruited in Canberra and 300 in Victoria.

Dementia is projected to become the leading cause of disability by 2016.  Consequently, "successful" cognitive ageing has become a significant goal for preventative medicine. Brain white matter ischaemia may cause cognitive decline in its own right, but is also present in the majority of those with Alzheimer's disease (AD).  Vascular risk factors have emerged as important contributors to the development of AD and sub-clinical brain infarcts / ischaemia, the combination of which is the most common pathology found in community-based studies of older adults with cognitive decline.  Therefore small-vessel, vascular disease is an attractive target for primary preventative therapy.

Brain magnetic resonance imaging (MRI) changes correlate with white matter ischaemia / infarction, and potentially provide an efficient surrogate for cognitive decline.  However, MRI is relatively costly and is not universally accessible, making it impractical for population screening.  The retinal vasculature shares many features with that of the brain.  So, should changes in the two be highly correlated, retinal digital photography would provide the opportunity to combine a relatively inexpensive, widely available tool with automated analysis to select those likely to benefit most from a preventative intervention such as regular low-dose aspirin treatment.

This sub-study will commence in 2008 with study participants attending CTC for the retinal photography measurements and additional cognitive testing.