Arterial stiffness, pressure and flow pulsatility and brain structure and function: the Age, Gene/Environment Susceptibility – Reykjavik Study
Key result
Increased aortic stiffness is associated with harmful pulsatility transmission to the brain, leading to microvascular damage and lower cognitive performance (HR 1.62-1.71).
Population
Participants in the community-based Age, Gene/Environment Susceptibility--Reykjavik study who had no history…
Design
Cohort
Authors
Discussion
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Implication
Aortic stiffness may flag higher cognitive risk in older adults; hypothesis-generating and requires trials to test if stiffness reduction preserves brain health.
Key Points
- To determine whether disproportionate stiffening of the proximal aorta relative to the carotid arteries reduces wave reflection and transmits damaging pulsatile energy into cerebral microcirculation.
- Evaluated carotid pressure and flow, carotid-femoral pulse wave velocity, brain MRI, and cognitive performance in older community-dwelling adults without prior stroke, TIA, or dementia (n = 668, 378 females, aged 69–93 years).
- Assessed aortic characteristic impedance and calculated the aorta-carotid reflection coefficient in a random subset of participants (n = 422).
- Carotid flow pulsatility index negatively correlated with the aorta-carotid reflection coefficient (R = -0.66, P < 0.001) and was associated with lower whole brain (-0.127 ± 0.037 SD/SD, P < 0.001), grey matter (-0.079 ± 0.038 SD/SD, P = 0.038), and white matter volumes (-0.128 ± 0.039 SD/SD, P < 0.001).
- Carotid pulse pressure, pulsatility index, and carotid-femoral pulse wave velocity each associated with increased risk for silent subcortical infarcts (HR 1.62–1.71 per SD, P < 0.002), with pulse wave velocity also linking to white matter hyperintensity volume (0.108 ± 0.045 SD/SD, P = 0.018).
- Pulsatility index associated with lower memory scores (-0.165 ± 0.039 SD/SD, P < 0.001), slower processing speed (-0.118 ± 0.033 SD/SD, P < 0.001), and worse executive function (-0.155 ± 0.041 SD/SD, P < 0.001).
Structured PICO
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Population
Participants in the community-based Age, Gene/Environment Susceptibility--Reykjavik study who had no history of stroke, transient ischaemic attack or dementia (69-93 years of age, 56.6% female)
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Outcome
Brain magnetic resonance images (silent subcortical infarcts, white matter hyperintensity volume, brain volumes) and cognitive scores (memory, processing speed, executive function)surrogate
Increased aortic stiffness and excessive flow pulsatility are associated with microvascular structural brain damage and reduced cognitive performance in older adults.
Cite This Study
Mitchell et al. (2011) studied this question. Increased aortic stiffness is associated with harmful pulsatility transmission to the brain, leading to microvascular damage and lower cognitive performance (HR 1.62-1.71).