Perspectives on the relation of blood pressure and cognition in the elderly

Association of late-life blood pressure change with cerebral small vessel disease in the MIND-China study

OBJECTIVES

This study aimed to investigate the associations between changes in blood pressure (BP) and cerebral small vessel disease (CSVD).

METHODS

This study included 401 participants in the magnetic resonance imaging (MRI) sub-study conducted between 2018 and 2020 as a part of the Multidomain Interventions to Delay Dementia and Disability in Rural China project. MRI markers of CSVD were assessed based on international criteria. Individualized linear regression models evaluated changes in BP by estimating the trend of blood pressure changes over time and fitting a straight line from 2014 to 2018. The data were analyzed using logistic and general linear regression models.

RESULT

The mean age of the participants was 64.48 ± 2.69 years, with 237 (59.1%) being females. Increases in systolic BP in later life were significantly associated with larger volumes of periventricular white matter hyperintensity (WMH), greater perivascular spaces in the basal ganglia (BG-PVS) burden, and the presence of deep lacunes and cerebral microbleeds. Additionally, increases in diastolic BP in later life were significantly associated with the presence of infratentorial and deep lacunes.

CONCLUSIONS

CSVDs are associated with increased exposure to elevated BP later in life.

Acupuncture with twirling reinforcing and reducing manipulation shows a control of hypertension and regulation of blood pressure-related target brain regions in spontaneously hypertensive rat: a preliminary resting-state functional MRI study

Aim

To observe the effects of acupuncture manipulations on blood pressure and brain function in spontaneously hypertensive rats and elucidate the anti-hypertensive effect of the manipulations' central mechanism.

Methods

This study used acupuncture twirling reinforcing, acupuncture twirling reducing, and acupuncture twirling uniform reinforcing-reducing manipulations to act on the bilateral TaiChong point of rats. The depth of acupuncture was 1.5-2 mm, and twisting was performed at a frequency of 60 times/min within ±360° for 3 min, followed by the needle being retained for 17 min. Functional magnetic resonance imaging was performed at the end of the intervention. Regional homogeneity and amplitude of low-frequency fluctuations were used to assess the differences in brain regions in each group of rats, and the core brain region (left hypothalamus) among the differential brain regions was selected as the seed for functional connectivity analysis.

Results

(1) The anti-hypertensive effect was achieved by acupuncture manipulations, and the anti-hypertensive effect of twirling reducing manipulation on spontaneously hypertensive rats was better than that of twirling uniform reinforcing-reducing and twirling reinforcing manipulations. (2) After regional homogeneity and amplitude of low-frequency fluctuations analyses, the hypothalamus, the brain region related to blood pressure, was activated in the twirling uniform reinforcing-reducing manipulation group; the corpus callosum and cerebellum were activated in the twirling reinforcing manipulation group; and the hypothalamus, olfactory bulb, corpus callosum, brainstem, globus pallidum, and striatum were activated in the twirling reducing manipulation group. (3) According to the functional connectivity analysis, different acupuncture manipulations increased the functional connections between seed points and the brainstem, olfactory bulb, and cerebellum, etc.

Conclusion

These results suggest that acupuncture manipulations achieved the hypotensive effect and the twirling reducing manipulation had a better hypotensive effect on spontaneously hypertensive rats than twirling uniform reinforcing-reducing and twirling reinforcing manipulations; the central mechanism of the anti-hypertensive effect of twirling reinforcing and reducing manipulation may be related to the activation of brain regions associated with blood pressure regulation and the functional connections between them. Furthermore, brain regions involved in motor control, cognition, and hearing were also activated. We hypothesize that activation of these brain regions may help prevent or mitigate the onset and progression of hypertensive brain damage.

Hypertension and cognition are minimally associated in late life

Hypertension impacts approximately 65% of persons over 60 years of age. Although previous studies have proposed an association between mid-life hypertension and late-life cognition, reports of associations between late-life hypertension and cognition have been mixed in the direction and magnitude of the observed associations and in the cognitive domains that may be affected. This study contrasted older adults with and without self-reported hypertension at two time points in late life (M_{Baseline age} = 64.3 years, SD₁ = 0.7; M_{Follow-up age} = 71.2 years, SD₂ = 0.9), separated by approximately seven years. Participants included 4314 1957 high school graduates from the Wisconsin Longitudinal Study who were followed longitudinally until 2011. Cognitive, demographic, and health variables from the 2003-2005 and 2011 data collection waves were used. Cognitive measures included letter and category fluency, digit ordering, similarities, and immediate and delayed recall. Bayesian independent t tests and regressions examined the association between self-reported hypertension status and cognition at baseline and follow-up. Persons with self-reported hypertension over seven years showed slightly worse letter fluency and digit ordering performance at follow-up than persons without self-reported hypertension. No baseline cognitive differences were observed between groups. Participants with self-reported hypertension showed no improvement in letter fluency or digit ordering compared to persons without self-reported hypertension. After controlling for cardiovascular risk factors, hypertension was associated only with a slight decline in letter fluency. Finally, hypertension duration was not associated with cognitive performance. Self-reported hypertension was associated with minimal to no effects on cognition in older adults. Controlling for cardiovascular risk factors eliminated virtually all associations between self-reported hypertension and cognition.

Vascular Cognitive Impairment and Dementia

PURPOSE OF REVIEW

This article gives a broad overview of vascular cognitive impairment and dementia, including epidemiology, pathophysiology, clinical approach, and management. Emphasis is placed on understanding the common underlying types of cerebrovascular disease (including atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy) and awareness of rare inherited cerebrovascular disorders.

RECENT FINDINGS

The pathophysiology of vascular cognitive impairment and dementia is heterogeneous, and the most recent diagnostic criteria for vascular cognitive impairment and dementia break down the diagnosis of major vascular dementia into four phenotypic categories, including subcortical ischemic vascular dementia, poststroke dementia, multi-infarct dementia, and mixed dementia. Control of cardiovascular risk factors, including management of midlife blood pressure, cholesterol, and blood sugars, remains the mainstay of prevention for vascular cognitive impairment and dementia. Cerebral amyloid angiopathy requires special consideration when it comes to risk factor management given the increased risk of spontaneous intracerebral hemorrhage. Recent trials suggest some improvement in global cognitive function in patients with vascular cognitive impairment and dementia with targeted cognitive rehabilitation.

SUMMARY

Thorough clinical evaluation and neuroimaging form the basis for diagnosis. As vascular cognitive impairment and dementia is the leading nondegenerative cause of dementia, identifying risk factors and optimizing their management is paramount. Once vascular brain injury has occurred, symptomatic management should be offered and secondary prevention pursued.

Relationship between Arterial Hypertension with Cognitive Performance in Elderly. Systematic Review and Meta-Analysis

Background: Previous systematic reviews report that arterial hypertension (AHT) is associated with lower performance in cognition in the elderly. However, some studies show that with higher blood pressure, a better cognitive performance is obtained. Objective: The aim of this study was to determine the relationship between AHT with cognitive performance in the elderly. Methods: the review involved a search on PubMed, Scopus and PsycINFO databases from January 1990 to March, 2020 to identify the relationship among AHT and cognitive performance in older people. Results: 1170 articles were identified, 136 complete papers were reviewed, a qualitative analysis of 26 studies and a quantitative analysis of eight studies were carried out. It was found that people with AHT have a lower performance in processing speed SMD = 0.40 (95% CI: 0.25, 0.54), working memory SMD = 0.28 (95% CI: 0.15, 0.41) in short-term memory and learning SMD = −0.27 (95% CI: −0.37, −0.17) and delayed recall SMD = −0.20 (95% CI: −0.35, −0.05). Only one study found that higher blood pressure was associated with better memory performance. Conclusion: Our results suggest that high blood pressure primarily affects processing speed, working memory, short-term memory and learning and delayed recall.

Withdrawal of antihypertensive drugs in older people

BACKGROUND

Hypertension is an important risk factor for subsequent cardiovascular events, including ischaemic and haemorrhagic stroke, myocardial infarction, heart failure, chronic kidney disease, cognitive decline and premature death. Overall, the use of antihypertensive medications has led to reduction in cardiovascular disease, morbidity rates and mortality rates. However, the use of antihypertensive medications is also associated with harms, especially in older people, including the development of adverse drug reactions, drug-drug interactions and can contribute to increasing medication-related burden. As such, discontinuation of antihypertensives may be considered and appropriate in some older people.

OBJECTIVES

To investigate whether withdrawal of antihypertensive medications is feasible, and evaluate the effects of withdrawal of antihypertensive medications on mortality, cardiovascular outcomes, hypertension and quality of life in older people.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to April 2019: the Cochrane Hypertension Specialised Register, CENTRAL (2019, Issue 3), Ovid MEDLINE, Ovid Embase, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also conducted reference checking, citation searches and, when appropriate, contacted study authors to identify any additional studies. The searches had no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of withdrawal versus continuation of antihypertensive medications used for hypertension or primary prevention of cardiovascular disease in older adults (defined as 50 years and over). Participants were eligible if they lived in the community, residential aged care facilities, or were based in hospital settings. We sought to include trials looking at the complete withdrawal of the antihypertensive medication, and those focusing on a dose reduction of the antihypertensive medicine.

DATA COLLECTION AND ANALYSIS

We compared the intervention of discontinuing or reducing antihypertensive medication to usual treatment using mean differences (MD) and 95% confidence intervals (95% CIs) for continuous variables and we used Peto odds ratios (ORs) and 95% CI for binary variables. Our primary outcomes included: mortality, myocardial infarction, development of adverse drug reactions or adverse drug withdrawal reactions. Secondary outcomes included: blood pressure, hospitalisation, stroke, success of withdrawing from antihypertensives, quality of life, and falls. Two authors independently, and in duplicate, conducted all stages of study selection, data extraction and quality assessment.

MAIN RESULTS

Six RCTs met the inclusion criteria and were included in the review (1073 participants). Study duration and follow-up ranged from 4 weeks to 56 weeks. Meta-analysis of studies showed that, in the discontinuation group compared to continuation, the odds for all-cause mortality were 2.08 (95% CI 0.79 to 5.46; low certainty of evidence), for myocardial infarction 1.86 (95% CI 0.19 to 17.98; very low certainty of evidence) and for stroke 1.44 (95% CI 0.25 to 8.35; low certainty of evidence). Blood pressure was higher in the discontinuation group than the continuation group (systolic blood pressure: MD = 9.75 mmHg, 95% CI 7.33 to 12.18; and diastolic blood pressure: MD = 3.5 mmHg, 95% CI 1.82 to 5.18; low certainty of evidence). For the development of adverse events, meta-analysis was not possible; antihypertensive discontinuation did not appear to increase the risk of adverse events and may lead to resolution of adverse drug reactions, although eligible studies had limited reporting of adverse effects of drug withdrawal (very low certainty of evidence). One study reported hospitalisation with an odds ratio of 0.83 for discontinuation compared to continuation (95% CI 0.33 to 2.10; low certainty of evidence). No studies were identified which reported falls. Between 10.5% and 33.3% of participants in the discontinuation group compared to 9% to 15% in the continuation group experienced raised blood pressure or other clinical criteria (as pre-defined by the studies) that would require restarting of therapy/removal from the study. The sources of bias included selective reporting (reporting bias), lack of blinding of outcome assessment (detection bias), incomplete outcome data (attrition bias), and lack of blinding of participants and personnel (performance bias).

AUTHORS' CONCLUSIONS

There is no evidence of an effect of discontinuing compared with continuing antihypertensives used for hypertension or primary prevention of cardiovascular disease in older adults on all-cause mortality and myocardial infarction. The evidence was low to very low certainty mainly due to small studies and low event rates. These limitations mean that we cannot make any firm conclusions about the effect of deprescribing antihypertensives on these outcomes. Future research should focus on populations with the greatest uncertainty of the benefit:risk ratio for use of antihypertensive medications, such as those with frailty, older age groups and those taking polypharmacy, and measure clinically important outcomes such as falls, quality of life and adverse drug events.

Management of blood pressure in stroke

Objective

In this review and opinion piece, we discuss recent United States (US)-based guidance statements on the management of BP in stroke according to stroke type and stage of stroke.

Methods

We reviewed the most recent guidance statements on BP control from United States (US)-based organizations such as the American Heart Association/American Stroke Association (AHA/ASA) and American College of Cardiology (ACC), and articles available to the authors in their personal files.

Results

The key BP target before starting alteplase (t-PA) is < 185/110 mm Hg, and the maintenance BP after tPA administration is < 180/105 mm Hg. For IPH patients with systolic BP between 150 and 220 mm Hg and no contraindication to acute BP reduction therapy, acute lowering to 140 mm Hg systolic BP is safe. For persons with small vessel or lacunar cerebral ischemia, a reasonable BP lowering target is < 130 mm Hg systolic. For primary stroke prevention, the target BP for those with hypertension is < 140/90 mm Hg and self-measured BP is recommended to assist in BP control. Recent study and guidance suggest a BP target of <130/80 mm Hg for both primary and recurrent stroke prevention. BP control is reasonable for the prevention of cognitive decline or dementia.

Conclusions

BP targets for the proper management of stroke vary by chronological stage of stroke and by stroke subtype. Furthermore, consideration should be given to control of BP variability, especially in the acute phases of stroke, as it may play a role in conferring longer term outcomes.

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Stroke is an important cause of morbidity and mortality worldwide, and is well suited for prevention and acute treatment with proper BP management.

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BP targets in acute ischemic stroke vary whether intravenous alteplase is administered or an endovascular intervention is implemented or not.

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In acute intraparenchymal hemorrhage of the brain (IPH), it is reasonable to lower BP to a systolic level of 140–150 or up to 160 mm Hg.

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For both first and recurrent stroke prevention it is reasonable to aim for a BP target of <130/80 mm Hg based on the recent data.

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The revised BP target has been lowered to <130/80 mm Hg for prevention of major cardiovascular outcomes including stroke.

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Intensive BP control potentially preserves cognition, brain health, and brain structural integrity.

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Blood pressure variability is a new target for study in the acute treatment and prevention of stroke.