Longitudinal trajectories of cognitive decline among older adults with cardiovascular disease

Abstract

Background: The long-term course of cognitive impairments secondary to cardiovascular disease (CVD) is unclear. In this study, we prospectively investigated the temporal pattern, rate and hierarchy of cognitive decline attributable to CVD--a risk factor for the development of vascular cognitive impairment (VCI)--and examined the influence of cardiac surgery and heart failure on cognitive decline.

Methods: A total of 172 older adults with CVD were administered a comprehensive battery of neuropsychological tests at study entry, and at 12 and 36 months thereafter. Random coefficient regressions were used to investigate the temporal course, rate and hierarchy of cognitive decline, as well as to examine the effect of heart failure (reported by 21% of the sample) and cardiac surgery (reported by 44% of the sample) on trajectories of cognitive change.

Results: The course of decline in cognition was linear for language and attention-executive function-psychomotor speed, and curvilinear for visuospatial abilities, memory and overall cognition. The decline in attention-executive function-psychomotor speed was smaller than the decline in other domains. The greatest decline occurred in visuospatial abilities. The rate of decline in cognition was not altered by a history of heart failure. Patients who had undergone cardiac surgery exhibited slower deceleration in their rates of decline in overall cognition. At baseline, patients with a history of heart failure had comparatively poorer attention-executive function-psychomotor speed, overall cognition and, to a lesser extent, visuospatial scores.

Conclusion: There is measurable decline in neurocognitive function among patients with CVD. This decline is linear in some cognitive domains and curvilinear in others and is not attributable to the normal aging process. Cardiac surgery, but not heart failure, significantly affects the trajectory of cognitive decline. Because most vascular risk factors are modifiable, preventive measures such as lifestyle changes may be useful in retarding cognitive decline among patients with CVD, thus preventing the onset of VCI.

Fig. 1

Temporal patterns of change in cognitive function across time. The regression lines for language and attention-executive function-psychomotor speed were derived from linear models, whereas those for visuospatial abilities, memory and overall cognition were derived from quadratic models.

Fig. 2

Effect of major cardiac surgery on change in overall cognition.