Cardiac output as a potential risk factor for abnormal brain aging

Sex-dependent effects of antimicrobials and lipopolysaccharide on blood-brain-barrier permeability in pubertal male and female CD1 mice

Exposure to stressors during puberty can disrupt normal development and possibly increase susceptibility to neurodegenerative disorders later in life. However, the mechanisms underlying the relationship between pubertal stress exposure and neurodegeneration remain unclear. As such, the current study was designed to examine the effects of pubertal antimicrobial (AMNS) and lipopolysaccharide (LPS) treatments on intestinal and blood-brain-barrier (BBB) permeability in male and female mice. Moreover, we also examined the sex-specific effects of pubertal AMNS and LPS treatments on gross motor activity, heart rate, and core body temperature. At four weeks of age, male and female CD1 mice were implanted with the G2 HR E-Mitter telemetry system. At five weeks of age, mice received 200 μL of broad-spectrum antimicrobial or water, through oral gavage, twice daily for seven days. Mice received an intraperitoneal injection of either saline or LPS at six weeks of age. BBB and intestinal permeability were examined 24 h, 72 h, and one week post-LPS/saline treatment. Telemetric data was collected for 48 h post-LPS/saline treatment. The results showed that pubertal AMNS and LPS treatments increased sickness behaviours and decreased body temperature and heart rate, in a sex-dependent manner. Furthermore, pubertal AMNS and LPS treatments resulted in sex-dependent regional increases in BBB permeability 24 h and 72 h post-LPS/saline treatment, while global increases in BBB permeability were only observed one week post-LPS/saline treatment. These results further our understanding of the combined effects of AMNS and LPS treatments on physiology and on the enduring negative changes observed following pubertal exposure to stressors.

Cognitive dysfunction in diabetes-related foot complications: A cohort study

Objective

Mild-moderate cognitive impairment has been identified in general diabetes, and early evidence indicates cognitive reductions may be more pronounced in those with diabetes-related foot complications (DRFC). Cognitive difficulties may impede treatment engagement and self-management. This requires further explication to optimise patient care and outcomes. The current study aimed to characterise cognitive function in people with DRFC using comprehensive cognitive measures.

Method

This cross-sectional cohort study recruited 80 adult participants (M age  = 63.38, SD = 11.40, range = 30 - 89) from the Royal Melbourne Hospital Diabetic Foot Unit in Victoria, Australia, all with DRFC. Each completed a comprehensive cognitive battery (memory, attention, executive functions) and scores were calculated using age-matched population norms, where available.

Results

On the majority of tasks, DRFC participants performed significantly worse than age-matched norms, with the largest decrements seen in inhibition control, verbal memory, verbal abstract reasoning and working memory. Small to moderate reductions were also seen in visual learning, verbal fluency, processing speed and premorbid functioning. Demographic (lower education, male gender) and clinical factors (higher HbA1c, macrovascular and microvascular disease, longer diabetes duration) were associated with poorer cognitive functioning.

Conclusions

Marked reductions in cognitive functioning were found in individuals with DRFC, predominantly in the domains of verbal memory and executive functioning. Lower education, male gender and indicators of diabetes severity, such as vascular disease, are associated with heightened risk for poorer cognitive functioning. As DRFCs are a serious complication with devastating outcomes if not successfully managed, cognitive barriers to self-management must be addressed to optimise treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01381-4.

Food Insecurity, Memory, and Dementia Among US Adults Aged 50 Years and Older

Importance

Despite existing federal programs to increase access to food, food insecurity is common among US older adults. Food insecurity may affect Alzheimer disease and Alzheimer disease-related dementias via multiple mechanisms, yet there is almost no quantitative research evaluating this association.

Objective

To examine whether food insecurity in older adults is associated with later-life cognitive outcomes.

Design, Setting, and Participants

This cohort study of US residents aged 50 years and older from the US Health and Retirement Study was restricted to respondents with food insecurity data in 2013 and cognitive outcome data between calendar years 2014 and 2018. Analyses were conducted from June 1 to September 22, 2023.

Exposure

Food insecurity status in 2013 was assessed using the validated US Department of Agriculture 6-item Household Food Security Module. Respondents were classified as being food secure, low food secure, and very low food secure.

Main Outcomes and Measures

Outcomes were dementia probability and memory score (standardized to 1998 units), estimated biennially between 2014 and 2018 using a previously validated algorithm. Generalized estimation equations were fit for dementia risk and linear mixed-effects models for memory score, taking selective attrition into account through inverse probability of censoring weights.

Results

The sample consisted of 7012 participants (18 356 person-waves); mean (SD) age was 67.7 (10.0) years, 4131 (58.9%) were women, 1136 (16.2%) were non-Hispanic Black, 4849 (69.2%) were non-Hispanic White, and mean (SD) duration of schooling was 13.0 (3.0) years. Compared with food-secure older adults, experiencing low food security was associated with higher odds of dementia (odds ratio, 1.38; 95% CI, 1.15-1.67) as was experiencing very low food security (odds ratio, 1.37; 95% CI, 1.11-1.59). Low and very low food security was also associated with lower memory levels and faster age-related memory decline.

Conclusions and Relevance

In this cohort study of older US residents, food insecurity was associated with increased dementia risk, poorer memory function, and faster memory decline. Future studies are needed to examine whether addressing food insecurity may benefit brain health.

Interaction effect of midday napping duration and depressive symptoms on subjective memory impairment among older people in China: evidence from the China health and retirement longitudinal study database

BACKGROUND

Subjective memory impairment (SMI) is common in older people. The aim of this study was to investigate the factors influencing SMI among older people in China, with specific focus on the interaction effect of midday napping duration and depressive symptoms on the risk of SMI.

METHODS

Using a dataset representative of the Chinese population from a longitudinal study of health and retirement in China, subjects with SMI were screened using the question "how do you feel about your memory now?" and the Mini-Mental State Examination. A logistic regression model was applied to explore the factors affecting SMI. Additive and multiplicative models were used to analyze the interaction effect of midday napping duration and depressive symptoms on the risk of SMI.

RESULTS

We enrolled 8,254 subjects included and the incidence of SMI was 63.9%. Depressive symptoms, nap time, and physical activity were influencing factors of SMI. Midday napping duration and depressive symptoms had positive additive interaction effects on the risk of SMI. When extended-length naps and depressive symptoms coexisted, the risk of SMI was 1.06 times greater than that for either alone (RERI, relative excess risk due to interaction = 0.27, 95% CI = 0.07-0.43; AP, attributable proportion = 0.14, 95% CI = 0.01-0.23; S, synergy index = 1.06, 95% CI = 0.57-1.62). When short naps and depressive symptoms coexisted, the risk of SMI was 1.2 times higher than that for either alone (RERI = 0.12, 95% CI=-0.14-0.39; AP = 0.13, 95% CI=-0.07-0.22; S = 1.20, 95% CI = 0.79-1.82).

LIMITATIONS

Since this was a cross-sectional study, the cause-and-effect relationships between the associated variables cannot be inferred.

CONCLUSIONS

The interaction effect that exists between nap time and depressive symptoms in older people is important for the identification and early intervention of people at risk for SMI.

Racial/Ethnic Disparities in the Alzheimer's Disease Link with Cardio and Cerebrovascular Diseases, Based on Hawaii Medicare Data

Background

There is an expanding body of literature implicating heart disease and stroke as risk factors for Alzheimer's disease (AD). Hawaii is one of the six majority-minority states in the United States and has significant racial health disparities. The Native-Hawaiians/Pacific-Islander (NHPI) population is well-known as a high-risk group for a variety of disease conditions.

Objective

We explored the association of cardiovascular disease with AD development based on the Hawaii Medicare data, focusing on racial disparities.

Methods

We utilized nine years of Hawaii Medicare data to identify subjects who developed heart failure (HF), ischemic heart disease (IHD), atrial fibrillation (AF), acute myocardial infarction (AMI), stroke, and progressed to AD, using multistate models. Propensity score-matched controls without cardiovascular disease were identified to compare the risk of AD after heart disease and stroke. Racial/Ethnic differences in progression to AD were evaluated, accounting for other risk factors.

Results

We found increased risks of AD for AF, HF, IHD, and stroke. Socioeconomic (SE) status was found to be critical to AD risk. Among the low SE group, increased AD risks were found in NHPIs compared to Asians for all conditions selected and compared to whites for HF, IHD, and stroke. Interestingly, these observations were found reversed in the higher SE group, showing reduced AD risks for NHPIs compared to whites for AF, HF, and IHD, and to Asians for HF and IHD.

Conclusions

NHPIs with poor SE status seems to be mostly disadvantaged by the heart/stroke and AD association compared to corresponding whites and Asians.

Higher body weight-dependent neural activation during reward processing

Obesity is associated with alterations in brain structure and function, particularly in areas related to reward processing. Although brain structural investigations have demonstrated a continuous association between higher body weight and reduced gray matter in well-powered samples, functional neuroimaging studies have typically only contrasted individuals from the normal weight and obese body mass index (BMI) ranges with modest sample sizes. It remains unclear, whether the commonly found hyperresponsiveness of the reward circuit can (a) be replicated in well-powered studies and (b) be found as a function of higher body weight even below the threshold of clinical obesity. 383 adults across the weight spectrum underwent functional magnetic resonance imaging during a common card-guessing paradigm simulating monetary reward. Multiple regression was used to investigate the association of BMI and neural activation in the reward circuit. In addition, a one-way ANOVA model comparing three weight groups (normal weight, overweight, obese) was calculated. Higher BMI was associated with higher reward response in the bilateral insula. This association could no longer be found when participants with obesity were excluded from the analysis. The ANOVA revealed higher activation in obese vs. lean, but no difference between lean and overweight participants. The overactivation of reward-related brain areas in obesity is a consistent finding that can be replicated in large samples. In contrast to brain structural aberrations associated with higher body weight, the neurofunctional underpinnings of reward processing in the insula appear to be more pronounced in the higher body weight range.

Association of Arterial Spin Labeling Parameters With Cognitive Decline, Vascular Events, and Mortality in a Memory-Clinic Sample

BACKGROUND

Cognitive decline in older adults has been attributed to reduced cerebral blood flow (CBF). Recently, the spatial coefficient of variation (sCoV) of ASL has been proposed as a proxy marker of cerebrovascular insufficiency. We investigated the association between baseline ASL parameters with cognitive decline, incident cerebrovascular disease, and risk of vascular events and mortality.

DESIGN, SETTING, AND PARTICIPANTS

About 368 memory-clinic patients underwent three-annual neuropsychological assessments and brain MRI scans at baseline and follow-up. MRIs were graded for white matter hyperintensities (WMH), lacunes, cerebral microbleeds (CMBs), cortical infarcts, and intracranial stenosis. Baseline gray (GM) and white matter (WM) CBF and GM-sCoV were obtained with ExploreASL from 2D-EPI pseudo-continuous ASL images. Cognitive assessment was done using a validated neuropsychological battery. Data on incident vascular events (heart disease, stroke, transient ischemic attack) and mortality were obtained.

RESULTS

Higher baseline GM-sCoV was associated with decline in the memory domain over 3 years of follow-up. Furthermore, higher GM-sCoV was associated with a decline in the memory domain only in participants without dementia. Higher baseline GM-sCoV was associated with progression of WMH and incident CMBs. During a mean follow-up of 3 years, 29 (7.8%) participants developed vascular events and 18 (4.8%) died. Participants with higher baseline mean GM-sCoV were at increased risk of vascular events.

CONCLUSIONS

Higher baseline GM-sCoV of ASL was associated with a decline in memory and risk of cerebrovascular disease and vascular events, suggesting that cerebrovascular insufficiency may contribute to accelerated cognitive decline and worse clinical outcomes in memory clinic participants.

Augmented risk of dementia in hypertrophic cardiomyopathy: A propensity score matching analysis using the nationwide cohort

BACKGROUND

Dementia is a big medical and socioeconomic problem on aging society, and cardiac diseases have already shown a significant contribution to developing dementia. However, the risk of dementia related to hypertrophic cardiomyopathy (HCM), the most common inherited cardiomyopathy, has never been evaluated.

METHODS

In a large-scale longitudinal cohort using National Health Insurance database, 4,645 subjects with HCM aged ≥50 years between 2010 and 2016 were collected and matched with 13,935 controls, based on propensity scores (1:3). We investigated the incidence and risk of dementia, Alzheimer's disease (AD), and vascular dementia (VaD) between groups.

RESULTS

During follow-up (median 3.9 years after 1-year lag), incident dementia occurred in 739 subjects (4.0%): 78.2% for AD and 13.0% for VaD. The incidence of dementia, AD, and VaD were 23.0, 18.0, and 2.9/1,000 person-years, respectively, and was generally more prevalent in HCM. HCM group had a 50% increased risk of dementia, particularly AD, whereas there was no difference in the risk of VaD. The impact of HCM on AD (HR 1.52, 95% CI 1.26-1.84, p<0.001) was comparable with that of diabetes mellitus and smoking. Increased risk of AD in relation to HCM was consistent in various subgroups including younger healthier population.

CONCLUSIONS

This is the first to demonstrate the increased risk of dementia, mainly AD rather than VaD, in subjects with HCM. Early surveillance and active prevention for cognitive impairment could help for a better quality of life in an era that HCM is considered a chronic manageable disease with low mortality.

Associations of cognitive performance with cardiovascular magnetic resonance phenotypes in the UK Biobank

AIMS

Existing evidence suggests links between brain and cardiovascular health. We investigated associations between cognitive performance and cardiovascular magnetic resonance (CMR) phenotypes in the UK Biobank, considering a range of potential confounders.

METHODS AND RESULTS

We studied 29 763 participants with CMR and cognitive testing, specifically, fluid intelligence (FI, 13 verbal-numeric reasoning questions), and reaction time (RT, a timed pairs matching exercise); both were considered continuous variables for modelling. We included the following CMR metrics: left and right ventricular (LV and RV) volumes in end-diastole and end-systole, LV/RV ejection fractions, LV/RV stroke volumes, LV mass, and aortic distensibility. Multivariable linear regression models were used to estimate the association of each CMR measure with FI and RT, adjusting for age, sex, smoking, education, deprivation, diabetes, hypertension, high cholesterol, prior myocardial infarction, alcohol intake, and exercise level. We report standardized beta-coefficients, 95% confidence intervals, and P-values adjusted for multiple testing. In this predominantly healthy cohort (average age 63.0 ± 7.5 years), better cognitive performance (higher FI, lower RT) was associated with larger LV/RV volumes, higher LV/RV stroke volumes, greater LV mass, and greater aortic distensibility in fully adjusted models. There was some evidence of non-linearity in the relationship between FI and LV end-systolic volume, with reversal of the direction of association at very high volumes. Associations were consistent for men and women and in different ages.

CONCLUSION

Better cognitive performance is associated with CMR measures likely representing a healthier cardiovascular phenotype. These relationships remained significant after adjustment for a range of cardiometabolic, lifestyle, and demographic factors, suggesting possible involvement of alternative disease mechanisms.

The interaction and pathogenesis between cognitive impairment and common cardiovascular diseases in the elderly

Both cognitive impairment and cardiovascular diseases have a high incidence in the elderly population, increasing the burden of care and reducing the quality of life. Studies have suggested that cognitive impairment interacts with cardiovascular diseases such as coronary heart disease, abnormal blood pressure, heart failure, and arrhythmia. On one hand, cognitive impairment in the elderly influences the progression and self-management of cardiovascular diseases and increases the risk of cardiovascular-related adverse events. On the other hand, coronary heart disease, heart failure, higher blood pressure variability, orthostatic hypotension, and atrial fibrillation may aggravate cognitive impairment. The role of blood pressure levels on cognition remains controversial. Several shared biological pathways have been proposed as the underlying mechanism for the association. Cardiovascular diseases may lead to cognitive decline even dementia through cerebral perfusion damage, brain structural changes, inflammation, β-amyloid deposition, and neuroendocrine disorders. It is of great significance to study the interaction and put forward effective interventions in an overall perspective to reduce care burden and improve the quality of life of the elderly patients.

Brain age estimation at tract group level and its association with daily life measures, cardiac risk factors and genetic variants

Brain age can be estimated using different Magnetic Resonance Imaging (MRI) modalities including diffusion MRI. Recent studies demonstrated that white matter (WM) tracts that share the same function might experience similar alterations. Therefore, in this work, we sought to investigate such issue focusing on five WM bundles holding that feature that is Association, Brainstem, Commissural, Limbic and Projection fibers, respectively. For each tract group, we estimated brain age for 15,335 healthy participants from United Kingdom Biobank relying on diffusion MRI data derived endophenotypes, Bayesian ridge regression modeling and 10 fold-cross validation. Furthermore, we estimated brain age for an Ensemble model that gathers all the considered WM bundles. Association analysis was subsequently performed between the estimated brain age delta as resulting from the six models, that is for each tract group as well as for the Ensemble model, and 38 daily life style measures, 14 cardiac risk factors and cardiovascular magnetic resonance imaging features and genetic variants. The Ensemble model that used all tracts from all fiber groups (FG) performed better than other models to estimate brain age. Limbic tracts based model reached the highest accuracy with a Mean Absolute Error (MAE) of 5.08, followed by the Commissural ([Formula: see text]), Association ([Formula: see text]), and Projection ([Formula: see text]) ones. The Brainstem tracts based model was the less accurate achieving a MAE of 5.86. Accordingly, our study suggests that the Limbic tracts experience less brain aging or allows for more accurate estimates compared to other tract groups. Moreover, the results suggest that Limbic tract leads to the largest number of significant associations with daily lifestyle factors than the other tract groups. Lastly, two SNPs were significantly (p value [Formula: see text]) associated with brain age delta in the Projection fibers. Those SNPs are mapped to HIST1H1A and SLC17A3 genes.

Objectively assessed physical activity and sedentary behavior and global cognitive function in older adults: a systematic review

BACKGROUND

Both physical activity (PA) and sedentary behavior (SB) are important factors for healthy ageing. This systematic review aimed to determine the association of objectively assessed (instrumented) PA and SB with global cognitive function in older adults.

METHODS

PubMed, Embase, the Cochrane Library (via Wiley), CINAHL, PsychINFO, and SPORTDiscus (via EBSCO) were searched from inception to June 21, 2020 for articles that described associations of objectively assessed PA/SB with global cognitive function in older adults aged 60 years and older. Results were synthesized using an effect direction heat map and albatross plots portrayed estimated effect sizes (standardized regression coefficients (βs)), which were summarized in boxplots.

RESULTS

In total, 45 articles were included representing a total of 15,817 older adults (mean/median age ranged from 65 to 88 years; 49.5% female). Longitudinal studies (n = 7) showed that higher moderate-to-vigorous and light PA (MVPA and LPA, respectively) and lower SB were associated with better global cognitive function. Standardized βs of cross-sectional studies (n = 38) showed that lower SB (median [IQR], β = 0.078 [0.004-0.184] and higher LPA (β = 0.096 [0.046-0.188]), activity counts (β = 0.131 [0.049-0.224]), number of steps (β = 0.155 [0.096-0.246]), MVPA (β = 0.163 [0.069-0.285]) and total PA (TPA) (β = 0.174 [0.147-0.255]) were associated with better global cognitive function.

CONCLUSIONS

Higher PA and lower SB are associated with better global cognitive function in older adults. The greatest estimated effect sizes were found for moderate-to-vigorous and TPA, suggesting that greater duration of any PA, and high intensity PA could be most beneficial for global cognitive function.

Neurological complications of heart failure

Heart failure (HF) is a major global cause of death with increasing absolute worldwide numbers of HF patients. HF results from the interaction between cardiovascular aging with specific risk factors, comorbidities, and disease modifiers. The failing heart and neuronal injury have a bidirectional interaction requiring specific management strategies. Decreased cardiac output has been associated with lower brain volumes. Cerebral blood flow (CBF) may normalize following heart transplantation among severe HF patients. Stroke and cognitive impairment remain the main neurologic conditions associated with HF. However, HF patients may also suffer from chronic cerebral hypoperfusion. It seems likely that HF-related ischemic strokes are primarily the result of cardiac embolism. Atrial fibrillation (AF) is present in half of stroke patient with HF. The increased risk of hemorrhagic strokes is less well characterized and likely multifactorial, but may in part reflect a higher use of long-term antithrombotic therapy. The steady improvement of neuroimaging techniques has demonstrated an increased prevalence of silent ischemic lesions among HF patients. The populations most likely to benefit from long-term anticoagulant therapy are HF patients with AF. Cognitive impairment in HF can have a variety of clinical manifestations from mild memory problems to dementia.

Sex-Dependent End-of-Life Mental and Vascular Scenarios for Compensatory Mechanisms in Mice with Normal and AD-Neurodegenerative Aging

Life expectancy decreases with aging, with cardiovascular, mental health, and neurodegenerative disorders strongly contributing to the total disability-adjusted life years. Interestingly, the morbidity/mortality paradox points to females having a worse healthy life expectancy. Since bidirectional interactions between cardiovascular and Alzheimer’s diseases (AD) have been reported, the study of this emerging field is promising. In the present work, we further explored the cardiovascular–brain interactions in mice survivors of two cohorts of non-transgenic and 3xTg-AD mice, including both sexes, to investigate the frailty/survival through their life span. Survival, monitored from birth, showed exceptionally worse mortality rates in females than males, independently of the genotype. This mortality selection provided a “survivors” cohort that could unveil brain–cardiovascular interaction mechanisms relevant for normal and neurodegenerative aging processes restricted to long-lived animals. The results show sex-dependent distinct physical (worse in 3xTg-AD males), neuropsychiatric-like and cognitive phenotypes (worse in 3xTg-AD females), and hypothalamic–pituitary–adrenal (HPA) axis activation (higher in females), with higher cerebral blood flow and improved cardiovascular phenotype in 3xTg-AD female mice survivors. The present study provides an experimental scenario to study the suggested potential compensatory hemodynamic mechanisms in end-of-life dementia, which is sex-dependent and can be a target for pharmacological and non-pharmacological interventions.

Serum Levels of BDNF in Cardiovascular Protection and in Response to Exercise

As doenças cardiovasculares (DCV) são atualmente a maior causa de morte no Brasil e no mundo. Em 2016 as DCV foram responsáveis por mais de 17 milhões de mortes, representando 31% de todas as mortes em nível global. Mecanismos moleculares e genéticos podem estar envolvidos na proteção cardiovascular e devem ser considerados nas novas abordagens terapêuticas. Nesse sentido, recentes estudos têm relatado que o Fator Neurotrófico Derivado do Encéfalo (Brain-Derived Neurotrophic Factor, BDNF) está reduzido em indivíduos predispostos a desenvolverem DCV, e que o treinamento físico aeróbio aumenta as quantidades de BDNF circulante. O BDNF é uma neurotrofina encontrada em altas concentrações no hipocampo e córtex cerebral, sendo considerada molécula-chave na manutenção da plasticidade sináptica e na sobrevivência das células neuronais. Além da plasticidade neuronal, BDNF também é importante na função vascular, promovendo angiogênese por meio da regulação por espécies reativas de oxigênio (ROS). Entretanto, uma variante do gene do BDNF em humanos, o polimorfismo Val66Met (substituição do aminoácido valina por uma metionina na posição 66 do códon), que ocorre em 20-30% da população caucasiana, pode afetar as concentrações de BDNF no plasma e sua atividade em todos os tecidos periféricos contendo receptores tirosina quinase B (TrkB), como o endotélio. De fato, recentemente observamos que o polimorfismo Val66Met prejudica a reatividade vascular e o BDNF circulante em resposta ao treinamento físico. Dessa forma, apresentaremos a seguir uma discussão sobre os níveis séricos de BDNF na proteção cardiovascular, a variante genética Val66Met na reatividade vascular e o efeito do exercício físico.

Neurovascular Coupling Impairment in Heart Failure with Reduction Ejection Fraction

The hemodynamic consequences of a persistent reduced ejection fraction and unknown cardiac output on the brain have not been thoroughly studied. We sought to explore the status of the mechanisms of cerebrovascular regulation in patients with heart failure with reduced (HFrEF) and recovered (HFrecEF) ejection fraction. We monitored cerebral blood flow velocity (CBFV) with transcranial Doppler and blood pressure. Cerebral autoregulation, assessed by transfer function from the spontaneous oscillations of blood pressure to CBFV and neurovascular coupling (NVC) with visual stimulation were compared between groups of HFrEF, HFrecEF and healthy controls. NVC was significantly impaired in HFrEF patients with reduced augmentation of CBFV during stimulation (overshoot systolic CBFV 19.11 ± 6.92 vs. 22.61 ± 7.78 vs. 27.92 ± 6.84, p = 0.04), slower upright of CBFV (rate time to overshoot: 1.19 ± 3.0 vs. 3.06 (4.30) vs. 2.90 ± 3.84, p = 0.02); p = 0.023) and reduced arterial oscillatory properties (natural frequency 0.17 ± 0.06 vs. 0.20 ± 0.09 vs. 0.24 ± 0.07, p = 0.03; attenuation 0.34 ± 0.24 vs. 0.48 ± 0.35 vs. 0.50 ± 0.23, p = 0.05). Cerebral autoregulation was preserved. The neurovascular unit of subjects with chronically reduced heart pumping capability is severely dysfunctional. Dynamic testing with transcranial Doppler could be useful in these patients, but whether it helps in predicting cognitive impairment must be addressed in future prospective studies.

The central nervous system and heart failure

The view that chronic heart failure was exclusively a disease of the heart dominated the cardiovascular literature until relatively recently. However, over the last 40 years it has increasingly come to be seen as a multisystem disease. Aside from changes in the sympathetic and parasympathetic nervous systems and the renin-angiotensin-aldosterone system, adaptations to the lungs, muscles and gastrointestinal tract have been clearly documented. It is clear that the brain and CNS are also affected in patients with heart failure, although this is often under recognized. The purpose of this review is to summarize the changes in the structure and biochemical function of the CNS in patients with chronic heart failure and to discuss their potential importance.

Association of cardiovascular structure and function with cerebrovascular changes and cognitive function in older patients with end-stage renal disease

The Dutch prospective multicenter cohort study COPE (Cognitive decline in Older Patients with End stage renal disease) aimed to investigate the association of cardiovascular structure and function with cerebrovascular changes and cognitive function in 85 older patients with chronic kidney disease stage 4 and 5, awaiting either dialysis or conservative care. MRI was performed measuring aortic stiffness (pulse wave velocity [PWV]) and cardiac systolic function (ejection fraction and cardiac index). Outcomes were MRI-derived cerebrovascular changes (microbleeds, lacunes and white matter hyperintensities) and cognitive function (memory, executive function and psychomotor speed). Mean age was 76 years and 66% were male. No statistically significant associations were observed between cardiovascular parameters and cerebrovascular changes. Cognitive function was worse in patients with high compared to low PWV in all three cognitive domains. Although there were clinically relevant associations of high PWV with poor cognition in all domains, after adjustment for age, sex and education only the Trail Making Test A remained statistically significant (p=0.030). In conclusion, this study suggests that a higher PWV might be associated with lower cognitive function, suggesting that arterial stiffness may be an underlying mechanism of development of cognitive impairment in older patients with ESRD. Larger studies should replicate and extend these findings.

Associations between heart failure and risk of dementia: A PRISMA-compliant meta-analysis

BACKGROUND

There are differences among the outcomes regarding cognitive impairment in heart failure (HF) because the evidence is fragmented and sample size is small. Therefore we aimed to systematically review and analyze the available evidence about the association between HF and dementia.

METHODS

In the present study, we searched for articles published until August 2019 in the following databases: PubMed, Web of Science, EMBASE, Medline and Google Scholar. The pooled multivariate odds ratio (OR) or relative risk (RR) and 95% confidence intervals (CI) were obtained by the use of STATA 12.0 software.

RESULTS

The meta-analysis showed a positive association between HF and risk of all-cause dementia (OR/RR = 1.28, 95% CI 1.15 to 1.43, I = 70.0%, P < 0.001). Additionally, the study showed no significant association between HF and risk of Alzheimer's disease (AD) (OR/RR = 1.38, 95% CI 0.90 to 2.13, I = 74.8%, P = 0.008).

CONCLUSION

In conclusion, HF was associated with an increased risk of developing dementia. In addition, large scale prospective studies are essential to explore the associations between HF and risk of AD.

Cross-Sectional Associations Between Cardiac Biomarkers, Cognitive Performance, and Structural Brain Changes Are Modified by Age

Objective- NT-proBNP (N-terminal pro-B-type natriuretic peptide) and cardiac troponin T (cTNT) are associated with cognitive performance. Whether this extends to individuals <60 years of age is unclear. We investigated whether age modified the associations between NT-proBNP and cTNT and cognitive performance and structural brain changes. Approach and Results- In 3011 individuals (60±8 years; 49% women), NT-proBNP and cTNT, memory, information processing speed and executive functioning, grey matter (GM) and white matter, and white matter hyperintensity (WMH) volumes were determined. We used regression, adjusted for educational level, cardiovascular factors, and lifestyle factors, to test whether cross-sectional associations between biomarkers and cognitive performance and structural brain changes were modified by age (<60 versus ≥60 years). ≥60 years, higher NT-proBNP was associated with lower memory (β [SD] per 10-fold higher level [95% confidence interval (CI)], -0.11 [-0.22 to -0.00]), information processing speed (-0.12 [95% CI, -0.21 to -0.03]), executive functioning (-0.12 [95% CI, -0.22 to -0.03]), and smaller GM (β [mL] per 10-fold higher level, -6.89 [95% CI, -11.58 to -2.20]). Additionally, higher cTNT was associated with lower memory (-0.33 [95% CI, -0.53 to -0.12]) and information processing speed (-0.17 [95% CI, -0.3 to -0.01]); with smaller GM (-16.07 [95% CI, -24.90 to -7.24]) and greater WMH (10^β WMH per 10-fold higher level, 0.31 [95% CI, 0.10-0.52]). <60 years, NT-proBNP and cTNT were not associated with cognitive performance ( P_interaction, <0.10). In contrast, higher NT-proBNP was associated with smaller GM (-7.43 [95% CI, -11.70 to -3.16]) and greater WMH (0.13 [95% CI, 0.01-0.25]; P_interaction,>0.10). Higher cTNT was associated with greater WMH (0.18 [95% CI, -0.01 to 0.37]; P_interaction,>0.10) but not with GM (0.07 [95% CI, -6.87 to 7.02]; P_interaction, <0.10). Conclusions- Biomarkers of cardiac injury are continuously associated with structural brain changes in both older and younger individuals but with poorer cognitive performance only in older individuals. These findings stress the continuous nature of the heart-brain axis in the development of cognitive impairment.

Crosstalk between Peripheral Small Vessel Properties and Anxious-like Profiles: Sex, Genotype, and Interaction Effects in Mice with Normal Aging and 3×Tg-AD mice at Advanced Stages of Disease

Cardiovascular disease resulting from oxidative stress and inflammation can exacerbate Alzheimer's disease. This brief report provides the first evidence of compromised small peripheral mesenteric resistance artery (MRA) properties in 15-month-old 3xTg-AD mice. Females showed worse physiologically relevant MRA structural (increased passive external and internal diameters, cross sectional area) and functional (increased active internal diameters) alterations suggesting sex-dependent dysfunctions. At both physiological and high intraluminal pressures, vascular alterations correlated with the anxious-like behavioral profile, in a sex-dependent manner. Finally, the results unveil a crosstalk between peripheral small vessel properties and behavior in both 3xTg-AD mice and age-matched counterparts with normal aging.

Overexpression of miR-1 in the heart attenuates hippocampal synaptic vesicle exocytosis by the posttranscriptional regulation of SNAP-25 through the transportation of exosomes

BACKGROUND

The link between cardiac diseases and cognitive deterioration has been accepted from the concept of "cardiogenic dementia", which was proposed in the late 1970s. However, the molecular mechanism is unclarified.

METHODS

The two animal models used in this study were cardiac-specific overexpression of microRNA-1-2 transgenic (Tg) mice and a myocardial infarction mouse model generated by left coronary artery ligation (LCA). First, we observed the microRNA-1 (miR-1) level and synaptic vesicles (SV) distribution in the hippocampus using in situ hybridization and transmission electron microscopy (TEM) and evaluated the expression of vesicle exocytosis related proteins by western blotting. Second, we used dual luciferase reporter assay as well as antagonist and miRNA-masking techniques to identify the posttranscriptional regulatory effect of miR-1 on the Snap25 gene. Third, FM1-43 staining was performed to investigate the effect of miR-1 on synaptic vesicle exocytosis. Lastly, we used GW4869 to inhibit the biogenesis and secretion of exosomes to determine the transportation effect of exosomes for miR-1 from the heart to the brain.

RESULTS

Compared with the levels in age-matched WT mice, miR-1 levels were increased in both the hearts and hippocampi of Tg mice, accompanied by the redistribution of SVs and the reduction in SV exocytosis-related protein SNAP-25 expression. In vitro studies showed that SNAP-25 protein expression was down- or upregulated by miR-1 overexpression or inhibition, respectively, however, unchanged by miRNA-masking the 3'UTR of the Snap25 gene. SV exocytosis was inhibited by miR-1 overexpression, which could be prevented by co-transfection with an anti-miR-1 oligonucleotide fragment (AMO-1). The knockdown of miR-1 by hippocampal stereotaxic injection of AMO-1 carried by a lentivirus vector (lenti-pre-AMO-1) led to the upregulation of SNAP-25 expression and prevented SV concentration in the synapses in the hippocampi of Tg mice. The application of GW4869 significantly reversed the increased miR-1 level in the blood and hippocampi as well as reduced the SNAP-25 protein levels in the hippocampi of both Tg and LCA mice.

CONCLUSION

The overexpression of miR-1 in the heart attenuated SV exocytosis in the hippocampus by posttranscriptionally regulating SNAP-25 through the transportation of exosomes. This study contributes to the understanding of the relationship between cardiovascular disease and brain dysfunction.

Cerebral blood flow alteration following acute myocardial infarction in mice

Heart failure is associated with low cardiac output (CO) and low brain perfusion that imposes a significant risk for accelerated brain ageing and Alzheimer’s disease (AD) development. Although clinical heart failure can emerge several years following acute myocardial infarction (AMI), the impact of AMI on cerebral blood flow (CBF) at early stages and up to 30 days following MI is unknown. Sixteen months old male mice underwent left anterior descending (LAD) coronary artery ligation. Hemodynamics analyses were performed at baseline and at days 1, 7, and 30 post-MI. Left ventricular (LV) ejection fraction (EF), LV volumes, CO, and right common carotid artery (RCCA) diameter were recorded by echocardiography. RCCA flow (RCCA FL) was measured by Doppler echocardiography. LV volumes consistently increased (P<0.0012) and LV systolic function progressively deteriorated (P<0.0001) post-MI. CO and RCCA FL showed a moderate but significant decrease over the course of MI with similar fluctuation pattern such that both variables were decreased at day 1, increased at day 7, and decreased at 30 days post-MI. Correlation and regression analyses between CO and RCCA FL showed a strong correlation with significance at baseline and day 30 post-MI (R = 0.71, P=0.03, and R = 0.72, P=0.03, respectively). Days 1 and 7 analyses between CO and RCCA FL showed moderate correlation with non-significance post-MI (R = 0.51, P=0.2, and R = 0.56, P=0.12, respectively). In summary, CBF significantly decreased following AMI and remained significantly decreased for up to 30 days, suggesting a potential risk for brain damage that could contribute to cognitive dysfunction later in life.

N-Terminal pro-Brain Natriuretic Peptide and Associations With Brain Magnetic Resonance Imaging (MRI) Features in Middle Age: The CARDIA Brain MRI Study

Objective

As part of research on the heart–brain axis, we investigated the association of N-terminal pro-brain natriuretic peptide (NT-proBNP) with brain structure and function in a community-based cohort of middle-aged adults from the Brain Magnetic Resonance Imaging sub-study of the Coronary Artery Risk Development in Young Adults (CARDIA) Study.

Approach and results

In a cohort of 634 community-dwelling adults with a mean (range) age of 50.4 (46–52) years, we examined the cross-sectional association of NT-proBNP to total, gray (GM) and white matter (WM) volumes, abnormal WM load and WM integrity, and to cognitive function tests [the Digit Symbol Substitution Test (DSST), the Stroop test, and the Rey Auditory–Verbal Learning Test]. These associations were examined using linear regression models adjusted for demographic and cardiovascular risk factors and cardiac output. Higher NT-proBNP concentration was significantly associated with smaller GM volume (β = −3.44; 95% CI = −5.32, −0.53; p = 0.003), even after additionally adjusting for cardiac output (β = −2.93; 95% CI = −5.32, −0.53; p = 0.017). Higher NT-proBNP levels were also associated with lower DSST scores. NT-proBNP was not related to WM volume, WM integrity, or abnormal WM load.

Conclusion

In this middle-aged cohort, subclinical levels of NT-proBNP were related to brain function and specifically to GM and not WM measures, extending similar findings in older cohorts. Further research is warranted into biomarkers of cardiac dysfunction as a target for early markers of a brain at risk.

Association of Cardiac Structure and Function With Neurocognition in Hispanics/Latinos: The Echocardiographic Study of Latinos

Objective

To study the associations of comprehensive measures of cardiac structure and function with multidimensional neurocognitive measures.

Patients and Methods

The Echocardiographic Study of Latinos is a population-based cohort of Hispanic/Latino adults older than 45 years enrolled from October 1, 2011, through June 30, 2014. Neurocognitive measures included Word Fluency (WF), Brief-Spanish English Verbal Learning Test (B-SEVLT), and Digit Symbol Substitution Test. The B-SEVLT included B-SEVLT-recall and B-SEVLT-sum. Echocardiographic measures included cardiac structure, systolic and diastolic function, and myocardial strain. Multivariable regression models were fit using survey statistics and sampling probabilities.

Results

A total of 1794 participants (mean age, 56±0.5 years; 56% women) were included in the analysis. In the adjusted model, higher left ventricular mass index was associated with lower B-SEVLT-sum and Digit Symbol Substitution Test scores. Left ventricular systolic dysfunction was associated with lower WF scores. Abnormal left ventricular geometry was associated with lower B-SEVLT-sum scores. Higher relative wall thickness was associated with B-SEVLT-recall and B-SEVLT-sum scores. Mitral annular relaxation velocities were associated with lower B-SEVLT-recall, B-SEVLT-sum, and WF scores. Higher mitral inflow to annular early diastolic velocity ratio was associated with lower B-SEVLT-recall and B-SEVLT-sum scores. Diastolic dysfunction was associated with lower B-SEVLT-sum scores. Finally, lower global longitudinal strain was associated with lower WF scores.

Conclusion

Alterations in cardiac structure, systolic and diastolic function, and myocardial strain were associated with worse neurocognitive function. Further study is needed to determine the mechanisms (ie, impairment of cerebral flow and silent brain infarctions) mediating these heart-brain associations.

Cognitive decline in heart failure

Cognitive impairment (CI) is common in older adults with heart failure (HF). The prevalence of CI is higher among patients with HF than in those without. The spectrum of CI in HF is similar to that observed in the general population and may range from delirium to isolated memory or non-memory-related deficits to dementia. Both HF with reduced ejection fraction and HF with preserved ejection fraction have been associated with defects in different domains of cognition. Numerous risk factors have been shown to contribute to CI in HF. Additionally, various pathophysiological mechanisms related to HF can contribute to cognitive decline. These conditions are not routinely screened for in clinical practice settings with HF populations, and guidelines on optimal assessment strategies are lacking. Validated tools and criteria should be used to differentiate acute cognitive decline (delirium) from chronic cognitive decline such as mild cognitive impairment and dementia. CI in HF has been associated with higher rates of disability and impairment in self-care activities that may in turn increase healthcare cost, hospital readmission and mortality. Early detection of CI may improve clinical outcomes in older adults with HF. Appropriate HF management strategies may also help to reduce CI in patients with HF, and future research is needed to develop and test newer and more effective interventions to improve outcomes in patients with HF and CI.

Treatment of limited disease small cell lung cancer: the multidisciplinary team

Small cell lung cancer (SCLC) presents multiple interdisciplinary challenges with several paradigm shifts in its treatment in recent years. SCLC treatment requires multidisciplinary management and timely treatment. The aim of this review is to focus on the team management aspects in the treatment of limited disease SCLC and how this can contribute towards improving outcomes.

Magnetic Resonance Imaging of Cardiovascular Function and the Brain: Is Dementia a Cardiovascular-Driven Disease?

The proximal aorta acts as a coupling device between heart and brain perfusion, modulating the amount of pressure and flow pulsatility transmitted into the cerebral microcirculation. Stiffening of the proximal aorta is strongly associated with age and hypertension. The detrimental effects of aortic stiffening may result in brain damage as well as heart failure. The resulting cerebral small vessel disease and heart failure may contribute to early cognitive decline and (vascular) dementia. This pathophysiological sequence of events underscores the role of cardiovascular disease as a contributory mechanism in causing cognitive decline and dementia and potentially may provide a starting point for prevention and treatment. Magnetic resonance imaging is well suited to assess the function of the proximal aorta and the left ventricle (eg, aortic arch pulse wave velocity and distensibility) as well as the various early and late manifestations of cerebral small vessel disease (eg, microbleeds and white matter hyperintensities in strategically important regions of the brain). Specialized magnetic resonance imaging techniques are explored for diagnosing preclinical changes in white matter integrity or brain microvascular pulsatility.

Structural Brain Imaging of Long-Term Anabolic-Androgenic Steroid Users and Nonusing Weightlifters

BACKGROUND

Prolonged high-dose anabolic-androgenic steroid (AAS) use has been associated with psychiatric symptoms and cognitive deficits, yet we have almost no knowledge of the long-term consequences of AAS use on the brain. The purpose of this study is to investigate the association between long-term AAS exposure and brain morphometry, including subcortical neuroanatomical volumes and regional cortical thickness.

METHODS

Male AAS users and weightlifters with no experience with AASs or any other equivalent doping substances underwent structural magnetic resonance imaging scans of the brain. The current paper is based upon high-resolution structural T1-weighted images from 82 current or past AAS users exceeding 1 year of cumulative AAS use and 68 non-AAS-using weightlifters. Images were processed with the FreeSurfer software to compare neuroanatomical volumes and cerebral cortical thickness between the groups.

RESULTS

Compared to non-AAS-using weightlifters, the AAS group had thinner cortex in widespread regions and significantly smaller neuroanatomical volumes, including total gray matter, cerebral cortex, and putamen. Both volumetric and thickness effects remained relatively stable across different AAS subsamples comprising various degrees of exposure to AASs and also when excluding participants with previous and current non-AAS drug abuse. The effects could not be explained by differences in verbal IQ, intracranial volume, anxiety/depression, or attention or behavioral problems.

CONCLUSIONS

This large-scale systematic investigation of AAS use on brain structure shows negative correlations between AAS use and brain volume and cortical thickness. Although the findings are correlational, they may serve to raise concern about the long-term consequences of AAS use on structural features of the brain.

Prefrontal gray matter volume mediates genetic risks for obesity

Genetic and neuroimaging research has identified neurobiological correlates of obesity. However, evidence for an integrated model of genetic risk and brain structural alterations in the pathophysiology of obesity is still absent. Here we investigated the relationship between polygenic risk for obesity, gray matter structure and body mass index (BMI) by the use of univariate and multivariate analyses in two large, independent cohorts (n=330 and n=347). Higher BMI and higher polygenic risk for obesity were significantly associated with medial prefrontal gray matter decrease, and prefrontal gray matter was further shown to significantly mediate the effect of polygenic risk for obesity on BMI in both samples. Building on this, the successful individualized prediction of BMI by means of multivariate pattern classification algorithms trained on whole-brain imaging data and external validations in the second cohort points to potential clinical applications of this imaging trait marker.

Pathogenesis of depression- and anxiety-like behavior in an animal model of hypertrophic cardiomyopathy

Cardiovascular dysfunction is highly comorbid with mood disorders, such as anxiety and depression. However, the mechanisms linking cardiovascular dysfunction with the core behavioral features of mood disorder remain poorly understood. In this study, we used mice bearing a knock-in sarcomeric mutation, which is exhibited in human hypertrophic cardiomyopathy (HCM), to investigate the influence of HCM over the development of anxiety and depression. We employed behavioral, MRI, and biochemical techniques in young (3-4 mo) and aged adult (7-8 mo) female mice to examine the effects of HCM on the development of anxiety- and depression-like behaviors. We focused on females because in both humans and rodents, they experience a 2-fold increase in mood disorder prevalence vs. males. Our results showed that young and aged HCM mice displayed echocardiographic characteristics of the heart disease condition, yet only aged HCM females displayed anxiety- and depression-like behaviors. Electrocardiographic parameters of sympathetic nervous system activation were increased in aged HCM females vs. controls and correlated with mood disorder-related symptoms. In addition, when compared with controls, aged HCM females exhibited adrenal gland hypertrophy, reduced volume in mood-related brain regions, and reduced hippocampal signaling proteins, such as brain-derived neurotrophic factor and its downstream targets vs. controls. In conclusion, prolonged systemic HCM stress can lead to development of mood disorders, possibly through inducing structural and functional brain changes, and thus, mood disorders in patients with heart disease should not be considered solely a psychologic or situational condition.-Dossat, A. M., Sanchez-Gonzalez, M. A., Koutnik, A. P., Leitner, S., Ruiz, E. L., Griffin, B., Rosenberg, J. T., Grant, S. C., Fincham, F. D., Pinto, J. R. Kabbaj, M. Pathogenesis of depression- and anxiety-like behavior in an animal model of hypertrophic cardiomyopathy.

Cognitive impairment in heart failure: A protective role for angiotensin-(1-7)

Patients with congestive heart failure (CHF) have increased hospital readmission rates and mortality if they are concomitantly diagnosed with cognitive decline and memory loss. Accordingly, we developed a preclinical model of CHF-induced cognitive impairment with the goal of developing novel protective therapies against CHF related cognitive decline. CHF was induced by ligation of the left coronary artery to instigate a myocardial infarction (MI). By 4- and 8-weeks post-MI, CHF mice had approximately a 50% and 70% decline in ejection fraction as measured by echocardiography. At both 4- and 8-weeks post-MI, spatial memory performance in CHF mice as tested using the Morris water task was significantly impaired as compared with sham. In addition, CHF mice had significantly worse performance on object recognition when compared with shams as measured by discrimination ratios during the novel object recognition NOR task. At 8-weeks post-MI, a subgroup of CHF mice were given Angiotensin (Ang)-(1-7) (50mcg/kg/hr) subcutaneously for 4 weeks. Following 3 weeks treatment with systemic Ang-(1-7), the CHF mice NOR discrimination ratios were similar to shams and significantly better than the performance of CHF mice treated with saline. Ang-(1-7) also improved spatial memory in CHF mice as compared with shams. Ang-(1-7) had no effect on cardiac function. Inflammatory biomarker studies from plasma revealed a pattern of neuroprotection that may underlie the observed improvements in cognition. These results demonstrate a preclinical mouse model of CHF that exhibits both spatial memory and object recognition dysfunction. Furthermore, this CHF-induced cognitive impairment is attenuated by treatment with systemic Ang-(1-7). (PsycINFO Database Record

Brain in Congenital Heart Disease Across the Lifespan: The Cumulative Burden of Injury

The number of patients surviving with congenital heart disease (CHD) has soared over the last 3 decades. Adults constitute the fastest-growing segment of the CHD population, now outnumbering children. Research to date on the heart-brain intersection in this population has been focused largely on neurodevelopmental outcomes in childhood and adolescence. Mutations in genes that are highly expressed in heart and brain may cause cerebral dysgenesis. Together with altered cerebral perfusion in utero, these factors are associated with abnormalities of brain structure and brain immaturity in a significant portion of neonates with critical CHD even before they undergo cardiac surgery. In infancy and childhood, the brain may be affected by risk factors related to heart disease itself or to its interventional treatments. As children with CHD become adults, they increasingly develop heart failure, atrial fibrillation, hypertension, diabetes mellitus, and coronary disease. These acquired cardiovascular comorbidities can be expected to have effects similar to those in the general population on cerebral blood flow, brain volumes, and dementia. In both children and adults, cardiovascular disease may have adverse effects on achievement, executive function, memory, language, social interactions, and quality of life. Against the backdrop of shifting demographics, risk factors for brain injury in the CHD population are cumulative and synergistic. As neurodevelopmental sequelae in children with CHD evolve to cognitive decline or dementia during adulthood, a growing population of CHD can be expected to require support services. We highlight evidence gaps and future research directions.

Chronotropic Response and Cognitive Function in a Cohort at Risk for Alzheimer's Disease

The objective of this study was to examine the association of chronotropic response (CR) and heart rate (HR) recovery- two indices of cardiovascular function within the context of a graded exercise test- with cognitive performance in a cognitively healthy, late-middle-aged cohort at risk for Alzheimer's disease (AD). Ninety participants (age = 63.52±5.86 years; 65.6% female) from the Wisconsin Registry for Alzheimer's Prevention participated in this study. They underwent graded exercise testing and a comprehensive neuropsychological assessment that assessed the following four cognitive domains: Immediate Memory, Verbal & Learning Memory, Working Memory, and Speed & Flexibility. Regression analyses, adjusted for age, sex, and education, were used to examine the association between CR, HR recovery, and cognition. We found significant associations between CR and cognitive performance in the domains of Immediate Memory, Verbal Learning & Memory, and Speed & Flexibility. In contrast, HR recovery was not significantly associated with cognitive function. The association between CR and cognition persisted even after controlling for HR recovery. Together, these findings indicatethat, in a cognitively normal, late-middle-aged cohort, CR is a stronger correlate of cognitive performance than HR recovery. Overall, this study reinforces the idea that cardiovascular health plays an important role in cognitive function, specifically in a cohort at risk for AD; and that interventions that promote vascular health may be a viable pathway to preventing or slowing cognitive decline due to AD.

Case report: severe bradycardia, a reversible cause of "Cardio-Renal-Cerebral Syndrome"

Background

Cardio-Renal Syndromes were first classified in 2008 and divided into five subtypes. The type 1 Cardio-Renal Syndrome (CRS) is characterized by acute decompensation of heart failure leading to acute kidney injury (AKI). Bradyarrhythmia was not mentioned in the classification as a cause for low cardiac output (CO) in type 1 CRS. Besides, CRS was not previously associated with central nervous system (CNS) injury despite the fact that cardiac, renal and neurological diseases can coexist.

Case presentation

We report the case of a 93-year old diabetic man who presented for obnubilation. He had a slow atrial fibrillation, was not hypotensive and was not taking any beta-blocker. He developed, simultaneously, during his hospitalization, severe bradycardia (<35 beats per minute), oligoanuria and further neurological deterioration without profound hypotension. An ECG revealed a complete atrioventricular (AV) block and all his symptoms were completely reversed after pacemaker insertion. His creatinine decreased progressively afterwards and at discharge, he was conscious, alert and well oriented.

Conclusion

Our case highlights the importance of an early recognition of low cardiac output secondary to severe bradyarrhythmia and its concurrent repercussion on the kidney and the brain. This association of the CRS with CNS injury-that we called “Cardio-Renal-Cerebral Syndrome”–was successfully treated with permanent pacemaker implantation.

Novel mechanisms for cerebral blood flow regulation in patients with congenital heart disease

BACKGROUND

The mechanisms that regulate cerebral flow in patients after surgery for congenital heart diseases (CHDs) remain poorly understood. We tested our hypothesis that postoperative patients with CHD have disease- or hemodynamic-specific compensatory mechanisms for maintaining cerebral perfusion.

METHODS

A total of 89 children with specific hemodynamics including Glenn (n = 14), Fontan (n = 19), repaired tetralogy of Fallot (n = 24), and control patients (n = 32) were enrolled. The resistance and blood flow distribution between the brain (Rc and CIc) and lower body (Rs and CIs) were calculated by measuring the hemodynamic changes resulting from inferior vena cava occlusion during cardiac catheterization.

RESULTS

Despite considerable differences in cardiac index and superior vena cava pressure (SVCp), cerebral blood flow was preserved in all noncontrol groups, with a ratio between the vascular resistances in the cerebral and lower body circulation (Rc/Rs) that was significantly lower than that in controls. Interestingly, the reduced Rc/Rs of Glenn patients was mediated by the reduced Rc, whereas augmented Rs was conducive to the reduced Rc/Rs in the Fontan and tetralogy of Fallot groups. Multivariate analysis revealed that high SVCp was significantly associated with low Rc. Although low cardiac index was significantly associated with increased Rc and Rs, its impact was much greater on Rs than on Rc.

CONCLUSIONS

Compensatory mechanisms for cerebral flow regulation occur according to hemodynamic abnormality type in postoperative patients with CHD. Because such a regulation mechanism implies cerebral circulation fragility, further investigations are needed to address the impacts of cerebral circulation properties on neurodevelopmental outcomes.

N-terminal pro-brain natriuretic peptide and abnormal brain aging: The AGES-Reykjavik Study

OBJECTIVE

To investigate the independent association of serum N-terminal fragment of the prohormone natriuretic peptide (NT-proBNP) with structural and functional features of abnormal brain aging in older individuals.

METHODS

In this cross-sectional study based on the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study, we included 4,029 older community-dwelling individuals (born 1907 to 1935) with a measured serum level of NT-proBNP. Outcomes included parenchymal brain volumes estimated from brain MRI, cognitive function measured by tests of memory, processing speed, and executive functioning, and presence of depressive symptoms measured using the Geriatric Depression Scale. In a substudy, cardiac output of 857 participants was assessed using cardiac MRI.

RESULTS

In multivariate analyses, adjusted for sociodemographic and cardiovascular factors, higher levels of NT-proBNP were independently associated with lower total (p < 0.001), gray matter (p < 0.001), and white matter (p = 0.001) brain volumes. Likewise, in multivariate analyses, higher levels of NT-proBNP were associated with worse scores in memory (p = 0.005), processing speed (p = 0.001), executive functioning (p < 0.001), and more depressive symptoms (p = 0.002). In the substudy, the associations of higher NT-proBNP with lower brain parenchymal volumes, impaired executive function and processing speed, and higher depressive symptoms were independent of the level of cardiac output.

CONCLUSIONS

Higher serum levels of NT-proBNP, independent of cardiovascular risk factors and a measure of cardiac function, are linked with alterations in brain structure and function. Roles of natriuretic peptides in the process of brain aging need to be further elucidated.

Cardiac over-expression of microRNA-1 induces impairment of cognition in mice

Large cohort studies have revealed a close relationship between cognitive impairment and cardiovascular diseases, although the mechanism underlying this relationship remains incompletely understood. In this study, using a transgenic (Tg) mouse model of cardiac-specific over-expression of microRNA-1-2 (miR-1-2), we observed that microRNA-1 (miR-1) levels were increased not only in the heart but also in the hippocampus and blood, whereas its levels did not change in the skeletal muscle of Tg mice compared with age-matched wild-type (WT) mice. Six-month-old Tg mice showed cognitive impairment compared with age-matched WT mice, as assessed using the Morris Water Maze test. The brain-derived neurotrophic factor (BDNF) level and cyclic AMP-responsive element-binding protein (CREB) phosphorylation were also significantly reduced in the hippocampi of the Tg mice, as evaluated by Western blot. Further examination showed that BDNF protein expression was down- or up-regulated by miR-1 over-expression or inhibition, respectively, and was unchanged by binding site mutations or miRNA-masks for the 3'UTR of Bdnf, indicating that this gene is a potential target of miR-1. Knockdown of miR-1 by hippocampal stereotaxic injection of an anti-miR-1 oligonucleotide fragment carried by a lentivirus vector (lenti-pre-AMO-miR-1) led to up-regulation of BDNF expression and prevented the reduction in cognitive performance in the Tg mice without affecting cardiac function. Our findings demonstrate that cardiac over-expression of miR-1 also induces behavioral abnormalities that may be associated, at least in part, with the down-regulation of BDNF expression in the hippocampus. This study definitely contributes to the understanding of the relationship between cardiovascular disease and cognitive impairment.

Heart failure and Alzheimer's disease

It has recently been proposed that heart failure is a risk factor for Alzheimer's disease. Decreased cerebral blood flow and neurohormonal activation due to heart failure may contribute to the dysfunction of the neurovascular unit and cause an energy crisis in neurons. This leads to the impaired clearance of amyloid beta and hyperphosphorylation of tau protein, resulting in the formation of amyloid beta plaques and neurofibrillary tangles. In this article, we will summarize the current understanding of the relationship between heart failure and Alzheimer's disease based on epidemiological studies, brain imaging research, pathological findings and the use of animal models. The importance of atherosclerosis, myocardial infarction, atrial fibrillation, blood pressure and valve disease as well as the effect of relevant medications will be discussed.

Usefulness of cognitive dysfunction in heart failure to predict cardiovascular risk at 180 days

Cognitive dysfunction is common in patients with heart failure (HF). Despite the high prevalence and the adverse associations of cognitive dysfunction in HF, the prognostic implications remain poorly understood. We sought to determine the influence of cognitive dysfunction, identified using the Montreal Cognitive Assessment (MoCA), on 180-day cardiovascular events. We analyzed data on 246 participants in an observational cohort study of adults with HF. The interview-format MoCA was administered to all participants. Time to first cardiovascular event was assessed as a cumulative end point during the 180 days after enrollment. Cox proportional hazards model was used for analysis of time to first event. The MoCA score was <26 for 91 patients (37%). Patients with a MoCA score <26 were more likely to have a cardiovascular event at 180 days. MoCA score <26 remained an independent predictor of cardiovascular event risk at 180 days when adjusted for the Seattle Heart Failure Model Score and the Charlson comorbidity index (hazard ratio 1.7, 95% confidence interval 1.1 to 2.6, p = 0.03). In conclusion, in patients with HF, cognitive dysfunction identified with a MoCA score of <26 is associated with increased risk of cardiovascular events at 180 days.

Cardiac hemodynamics are linked with structural and functional features of brain aging: the age, gene/environment susceptibility (AGES)-Reykjavik Study

Background

Advanced heart failure is linked with structural and functional alterations in the brain. It is unclear whether a graded decrease in cardiac function puts older subjects at risk for brain aging. We investigated the association between cardiac hemodynamics and features of brain aging in community‐dwelling older subjects.

Methods and Results

With data from a sub‐study (n=931 subjects, mean age 75.9 years, 47.7% male) of the Age, Gene/Environment Susceptibility (AGES)‐Reykjavik Study, we investigated the association of MRI measures of cardiac hemodynamics, including left ventricular stroke volume (LVSV) and cardiac output (CO) to brain characteristics. In multivariable analyses, each 10 mL lower LVSV was associated with 4.4 mL (95% CI 1.9 to 6.9) lower total parenchymal brain volume (TBV) and 3.7 mL (95% CI 1.8 to 5.7) lower gray matter volume (GMV). Likewise, each unit (L/min) lower CO was associated with 3.9 mL (95% CI 0.4 to 7.4) lower TBV and 3.9 mL (95% CI 0.4 to 7.4) lower GMV. Lower LVSV was associated with worse performance in processing speed (P=0.043) and executive function (P<0.001). Lower CO was associated with worse performance in processing speed (P=0.015) and executive function (P=0.003). Each 10 mL lower LVSV and each unit lower CO associated with a higher risk of mild cognitive impairment or dementia (odds ratio: 1.24, 95% CI 0.99 to 1.57 and odds ratio: 1.40, 95% CI 0.99 to 2.00, respectively).

Conclusions

A graded decrease in cardiac functioning is associated with features of brain aging. Older persons with cardiac or cognitive signs and symptoms may have both cardiac and cerebral diseases and should be evaluated accordingly.

The KEEPS-Cognitive and Affective Study: baseline associations between vascular risk factors and cognition

Midlife vascular risk factors influence later cognitive decline and Alzheimer's disease (AD). The decrease in serum estradiol levels during menopause has been associated with cognitive impairment and increased vascular risk, such as high blood pressure (BP), which independently contributes to cognitive dysfunction and AD. We describe the extent to which vascular risk factors relate to cognition in healthy, middle-aged, recently postmenopausal women enrolled in the Kronos Early Estrogen Prevention Cognitive and Affective Study (KEEPS-Cog) at baseline. KEEPS-Cog is a double-blind, randomized, placebo-controlled, parallel group, clinical trial, investigating the efficacy of low-dose, transdermal 17β-estradiol and oral conjugated equine estrogen on cognition. All results are cross-sectional and represent baseline data only. Analyses confirm that the KEEPS-Cog cohort (n = 571) was middle aged (mean 52.7 years, range 42-59 years), healthy, and free of cognitive dysfunction. Higher systolic BP was weakly related to poorer performance in auditory working memory and attention (p = 0.004; adjusted for multiple comparisons p = 0.10). This relationship was not associated with endogenous hormone levels, and systolic BP was not related to any other cognitive domain. BP levels may be more sensitive than other vascular risk factors in detecting subtle differences in cognitive task performance in healthy, recently menopausal women. Lower BP early in menopause may affect cognitive domains known to be associated with AD.

Relationship between cognitive impairment and echocardiographic parameters: a review

With >24 million people affected worldwide, dementia is one of the main public health challenges modern medicine has to face. The path leading to dementia is often long, with a wide spectrum of clinical presentations, and preceded by a long preclinical phase. Previous studies have demonstrated that clinical strokes and covert vascular lesions of the brain contribute to the risk for developing dementia. Although it is not yet known whether preventing such lesions reduces the risk for dementia, it is likely that starting preventive measures early in the course of the disease may be beneficial. Echocardiography is a widely available, relatively inexpensive, noninvasive imaging modality whereby morphologically or hemodynamically derived parameters may be integrated easily into a risk assessment model for dementia. The aim of this review is to analyze the information that has accumulated over the past two decades on the prognostic value of echocardiographic factors in cognitive impairment. The associations between cognitive impairment and echocardiographic parameters, including left ventricular systolic and diastolic indices, left atrial morphologic parameters, cardiac output, left ventricular mass, and aortic root diameter, have previously been reported. In the light of these studies, it appears that echocardiography may help further improve currently used risk assessment models by allowing detection of subclinical cardiac abnormalities associated with future cognitive impairment. However, many limitations, including methodologic heterogeneity and the observational designs of these studies, restrict the scope of these results. Further prospective studies are required before integrating echocardiography into a preventive strategy.

Coronary heart disease and cortical thickness, gray matter and white matter lesion volumes on MRI

Coronary heart disease (CHD) has been linked with cognitive decline and dementia in several studies. CHD is strongly associated with blood pressure, but it is not clear how blood pressure levels or changes in blood pressure over time affect the relation between CHD and dementia-related pathology. The aim of this study was to investigate relations between CHD and cortical thickness, gray matter volume and white matter lesion (WML) volume on MRI, considering CHD duration and blood pressure levels from midlife to three decades later. The study population included 69 elderly at risk of dementia who participated in the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study. CAIDE participants were examined in midlife, re-examined 21 years later, and then after additionally 7 years (in total up to 30 years follow-up). MRIs from the second re-examination were used to calculate cortical thickness, gray matter and WML volume. CHD diagnoses were obtained from the Finnish Hospital Discharge Register. Linear regression analyses were adjusted for age, sex, follow-up time and scanner type, and additionally total intracranial volume in GM volume analyses. Adding diabetes, cholesterol or smoking to the models did not influence the results. CHD was associated with lower thickness in multiple regions, and lower total gray matter volume, particularly in people with longer disease duration (>10 years). Associations between CHD, cortical thickness and gray matter volume were strongest in people with CHD and hypertension in midlife, and those with CHD and declining blood pressure after midlife. No association was found between CHD and WML volumes. Based on these results, long-term CHD seems to have detrimental effects on brain gray matter tissue, and these effects are influenced by blood pressure levels and their changes over time.