Associations between White Matter Microstructural Integrity and Cognition in Older Adults with Coronary Artery Disease: A Diffusion Tensor Imaging Study

Coronary artery disease (CAD) is associated with an increased risk of cognitive decline. Conventional neuroimaging does not fully capture the effect of CAD on cognition. This study uses diffusion tensor imaging to determine whether subtle changes in white matter (WM) microstructural integrity can further predict CAD-associated cognitive impairment. Participants (n=49) were recruited at entry into cardiac rehabilitation. Composite Z-scores were computed for executive function and memory. Diffusion weighted magnetic resonance images were acquired. WM integrity as quantified by fractional anisotropy (FA) in the left parahippocampal cingulum was significantly associated with executive function (F(1,44)=11.43, p=.002). FA in 10 other WM tracts examined was also associated with executive function but did not survive statistical correction for multiple comparisons. No associations were observed between FA in WM tracts and memory. Subtle WM microstructural changes may contribute to pathophysiological mechanisms of cognitive decline in a population prone to early neural risk for dementia.M.Sc