Cardiac Index as a Correlate of Brain Volume

Abstract

The importance of vascular risk factors in the development and progression of cognitive disorders is gaining appreciation; the term “vascular cognitive disorders” refers to the common situation in which vascular damage plays a role, either alone or in combination with a neurodegenerative or other process, in the development of cognitive impairment or dementia. Numerous vascular risk factors have been implicated in vascular cognitive disorders, and many of these have been linked to cognitive decline through white matter damage and brain atrophy.1–8 As the American Heart Association launches its new strategic plan to improve the cardiovascular health of all Americans by 20%, a greater focus on ideal cardiovascular health will likely lead to improved brain health and therefore cognitive health. To address the health needs of our aging population, a better understanding of the links between cardiovascular disease and brain structure and function will be required. In addition, it will be important to identify early markers of unsuccessful aging to test interventions that can improve outcomes. Article see p 690 Various quantitative measures are now available to help us understand the relationships between vascular disease and brain health. These include neuropsychological testing, structural and functional magnetic resonance imaging, and metabolic imaging with magnetic resonance imaging and positron emission tomography. These tools have helped us better quantify changes in brain structure and metabolism and relate them to associations between aging, neurovascular risk factors, and cognitive function. In this issue of Circulation , Jefferson et al9 report an association between cardiac index and brain volume and relate these to cognitive function in a subsample of the well-characterized Framingham Study (participants were healthier than the overall cohort, being well enough to undergo magnetic resonance imaging). The brain volumes of participants were smaller among those with lower cardiac index values, even after adjustment …