Search

The population is ageing worldwide, thus increasing the burden of common age-related disorders to the individual, society and economy. Cerebrovascular diseases (stroke, dementia) contribute a significant proportion of this burden and are associated with high morbidity and mortality. Thus, understanding and promoting healthy vascular brain ageing are becoming an increasing priority for healthcare systems. In this review, we consider the effects of normal ageing on two major physiological processes responsible for vascular brain function: Cerebral autoregulation (CA) and neurovascular coupling (NVC). CA is the process by which the brain regulates cerebral blood flow (CBF) and protects against falls and surges in cerebral perfusion pressure, which risk hypoxic brain injury and pressure damage, respectively. In contrast, NVC is the process by which CBF is matched to cerebral metabolic activity, ensuring adequate local oxygenation and nutrient delivery for increased neuronal activity. Healthy ageing is associated with a number of key physiological adaptations in these processes to mitigate age-related functional and structural declines. Through multiple different paradigms assessing CA in healthy younger and older humans, generating conflicting findings, carbon dioxide studies in CA have provided the greatest understanding of intrinsic vascular anatomical factors that may mediate healthy ageing responses. In NVC, studies have found mixed results, with reduced, equivalent and increased activation of vascular responses to cognitive stimulation. In summary, vascular and haemodynamic changes occur in response to ageing and are important in distinguishing “normal” ageing from disease states and may help to develop effective therapeutic strategies to promote healthy brain ageing.

Orthostatic hypotension (OH) and atrial fibrillation (AF) are both regarded as independent risk factors for transient ischemic attack (TIA). However, the clinical implication of OH in the presence of AF is unclear. This study investigates, for the first time, the association between blood pressure (BP), OH and mortality in a cohort of patients with AF and TIA symptoms. To investigate the incidence of the association between OH, AF and TIA. This retrospective observational study utilised the Leicester one-stop transient TIA clinic patient database to consider the initial systolic and diastolic BP of 688 patients with a diagnosis of AF. The primary outcome was time until death. Covariant measures included status of AF diagnosis (known or new AF), cardiovascular risk factors, and primary clinic diagnosis [cerebrovascular (CV) versus non-cerebrovascular (non-CV)]. Statistical models adjusted for sex, age, previous AF diagnosis. Mortality rate was higher in the over 85 age group [191.5 deaths per 1000 person years (py) (95% CI 154.0–238.1)] and lower in the aged 75 and younger age group [40.0 deaths per 1000 py (95% CI 27.0–59.2)] compared to intermediate groups. A 10 mmHg increase in supine diastolic BP was associated with a significant reduction in the hazard of mortality for patients suspected of TIA with AF [adjusted HR 0.79 (95% CI 0.68–0.92), p

Healthy ageing has been associated with lower cerebral blood flow velocities (CBFVs); however, the behaviour of hemodynamic parameters associated with cerebrovascular tone (critical closing pressure, CrCP) and cerebrovascular resistance (resistance-area product, RAP) remains unclear. Specifically, evidence supports ageing being associated with greater cerebrovascular tone and resistance during exercise with elevated CrCP and RAP in older individuals at rest and during exercise. Comprehensive hemodynamic assessment of CrCP and RAP during hyperventilation-induced hypocapnia in two distinct age groups (young ≤ 49 and old > 50) has not been described. CBFV in the middle cerebral artery (CBFV, transcranial Doppler), blood pressure (BP, Finometer) and end-tidal CO2 (EtCO2, capnography) were recorded in 104 healthy individuals (43 young [age 33.8 (9.3) years], 61 old [age 64.1 (8.5) years]) during a minimum of 60 s of metronome-driven hyperventilation-induced hypocapnia. Autoregulation index was calculated as a function of time, using a moving window autoregressive-moving average model. CBFV was reduced in response to age (p

The Head Positioning in Acute Stroke Trial (HeadPoST) is a pragmatic, international, cluster crossover randomized trial of 11,093 patients with acute stroke assigned to a lying-flat (0°) or sitting-up (head elevated ≥30°) position. This post hoc analysis aimed to determine the association between blood pressure variability (BPV) and outcomes for patients from a wide range of international clinical settings and how the association was modified by randomized head position. BPV was defined according to the standard criteria, with the key parameter considered the coefficient of variation (CV) of systolic BP (SBP) over 24 h. Outcome was ordinal 90-day Modified Rankin Scale (mRS) score. The association was analyzed by ordinal, logistic regression, hierarchical, mixed models with fixed intervention (lying flat vs. sitting up), and fixed period, random cluster, and random cluster-period, effects. Nine thousand one hundred and fifty six (8324 acute ischemic stroke and 817 intracerebral hemorrhage; mean age 68.1 years; 39.2% women) were included in the analysis. CV of SBP had a significant linear association with unfavorable shift of mRS at 90 days (adjusted odds ratio 1.06, 95% confidence interval 1.02–1.11; P = 0.01). There was no heterogeneity of the association by randomized head positioning. In addition, CV of diastolic BP (DBP) (1.08, 1.03–1.12; P = 0.001) over 24 h post stroke was significantly associated with 3-month poor outcome. The association was more apparent in sitting-up position (1.12, 1.06–1.19) compared with lying-flat position (1.03, 0.98–1.09) (P interaction = 0.005). BPV was associated with adverse stroke outcome, and the magnitude of the association was greater with sitting-up head positioning in terms of DBP variability.