Cardiovascular exercise to prevent cognitive decline in high risk patient populations: a post-ischaemic stroke exercise intervention study

The two major causes of death, disability and reduced quality of life are dementia and stroke. Stroke is a potent risk factor for dementia. Ten percent of stroke
patients have cognitive impairments on admission; up to 30% have cognitive decline or dementia at 3 years. More than 70% of the total dementia burden in
Australia is due to the joint effect of combined vascular risk factors. Risk factors specific for post-stroke cognitive decline are recurrent stroke, hypertension,
and physical inactivity; in turn, physical inactivity is one of the strongest risk factors for recurrent stroke.
There are no current therapies to prevent cognitive decline from vascular risk. Exercise for dementia prevention is the neglected prescription. We will
examine whether a cardiac-rehabilitation style exercise intervention will preserve brain volume and cognition. In all dementias, atrophy precedes and predicts
cognitive decline, and we will track both. In our prior work, we have shown that stroke patients lose brain volume faster than control participants, and this
loss correlates with cognitive deficits.
We will recruit 100 stroke patients, randomised to a cardiovascular (aerobic exercise) or stretching arm, matching social contact. We will use advanced
imaging techniques to accurately measure brain volumes, scanning them before and after their intervention, and at one year. We will measure cognition at
each visit, and other potential variables, such as blood pressure, daily physical activity and blood biomarkers.
Interventions to prevent atrophy and cognitive decline are urgently needed. The identification of an efficacious exercise intervention would represent a major
public health advance, readily translatable and accessible to all Australians. Results from this study will provide unique information on the role of exercise in
preventing post-stroke dementia and brain atrophy. This study is potentially practice-changing, and will be directly implementable into clinical practice.