Aortic reservoir-excess pressure parameters are associated with worse cognitive function in people with untreated stage II/III hypertension.

Objective: Hypertension is a recognized risk factor for the development of cognitive impairment and dementia in older adults. Aortic stiffness and altered haemodynamics could promote the transmission of detrimental high pressure pulsatility into the cerebral circulation, potentially damaging brain microvasculature and leading to cognitive impairment. We determined whether reservoir-excess pressure parameters were associated with cognitive function in people with hypertension (HT) and normotension (NT).

Methods: We studied 35 middle-aged and older treatment-naïve stage II/III HT (office systolic BP 176 ± 17 mmHg) and 35 age-, sex- and body mass index-matched NT (office systolic BP 127 ± 8 mmHg). Parameters derived from reservoir-excess pressure analysis including reservoir pressure integral (INTPR), excess pressure integral (INTXSP), systolic rate constant (SRC), diastolic rate constant (DRC) and pulse wave velocity (PWV) were calculated from an ensemble-averaged aortic pressure waveform derived from radial artery tonometry. Cognitive function was assessed using the Addenbrooke's Cognitive Examination Revised (ACE-R), Trail Making Test Part A (TMT-A) and Part B (TMT-B).

Results: All reservoir-excess pressure parameters were greater in HT than NT (all P  < 0.05). Greater INTXSP was associated with lower ACE-R score ( rs  = -0.31), longer TMT-A ( r  = 0.31) and TMT-B ( r  = 0.38). Likewise, greater DRC and PWV were also associated with lower ACE-R score ( rs  = -0.27 and rs  = -0.33), longer TMT-A ( r  = 0.51 and r  = 0.40) and TMT-B ( r  = 0.38 and r  = 0.32). Greater INTXSP, DRC and PWV are consistently associated with worse cognitive function in this study.

Conclusions: These observations support a potential mechanistic link between adverse haemodynamics and a heightened risk of cognitive impairment in older adults with hypertension.