Reduced regional cerebral blood flow in patients with heart failure

Causal associations between chronic heart failure and the cerebral cortex: results from Mendelian randomization study and integrated bioinformatics analysis

Background

Chronic heart failure (CHF) patients exhibit alterations in cerebral cortical structure and cognitive function. However, the mechanisms by which CHF affects cortical structure and functional regions remain unknown. This study aims to investigate potential causal relationship between CHF and cerebral cortical structure through Mendelian randomization (MR).

Methods

The research utilized genome-wide association studies (GWAS) to explore the causal association between CHF and cerebral cortical structure. The results were primarily analyzed using the inverse-variance weighted (IVW). The reliability of the data was verified through horizontal pleiotropy and heterogeneity analysis by MR-Egger intercept test and Cochran's Q-test, respectively. Replication analysis was conducted in the Integrative Epidemiology Unit (IEU) OpenGWAS project for further validation. In addition, we collected mediator genes that mediate causality to reveal potential mechanisms. Integrated bioinformatics analysis was conducted using the Open Target Genetics platform, the STRING database, and Cytoscape software.

Results

The IVW results did not reveal any significant causal association between genetically predicted CHF and the overall structure of the cerebral cortex or the surface area (SA) of the 34 functional regions of the cerebral cortex (P > 0.05). However, the results revealed that CHF increased the thickness (TH) of pars opercularis (IVW: β = 0.015, 95% CI: 0.005-0.025, P = 3.16E-03). Replication analysis supported the causal association between CHF and pars opercularis TH (IVW: β = 0.02, 95% CI: 0.010-0.033, P = 1.84E-04). We examined the degree centrality values of the top 10 mediator genes, namely CDKN1A, CELSR2, NME5, SURF4, PSMA5, TSC1, RPL7A, SURF6, PRDX3, and FTO.

Conclusion

Genetic evidence indicates a positive correlation between CHF and pars opercularis TH.

Inhibition of Extracellular Signal-Regulated Kinase Activity Improves Cognitive Function in Mice Subjected to Myocardial Infarction

Cognitive impairment is a commonly observed complication following myocardial infarction; however, the underlying mechanisms are still not well understood. The most recent research suggests that extracellular signal-regulated kinase (ERK) plays a critical role in the development and occurrence of cognitive dysfunction-related diseases. This study aims to explore whether the ERK inhibitor U0126 targets the ERK/Signal Transducer and Activator of Transcription 1 (STAT1) pathway to ameliorate cognitive impairment after myocardial infarction. To establish a mouse model of myocardial infarction, we utilized various techniques including Echocardiography, Hematoxylin-eosin (HE) staining, Elisa, Open field test, Elevated plus maze test, and Western blot analysis to assess mouse cardiac function, cognitive function, and signal transduction pathways. For further investigation into the mechanisms of cognitive function and signal transduction, we administered the ERK inhibitor U0126 via intraperitoneal injection. Reduced total distance and activity range were observed in mice subjected to myocardial infarction during the open field test, along with decreased exploration of the open arms in the elevated plus maze test. However, U0126 treatment exhibited a significant improvement in cognitive decline, indicating a protective effect through the inhibition of the ERK/STAT1 signaling pathway. Hence, this study highlights the involvement of the ERK/STAT1 pathway in regulating cognitive dysfunction following myocardial infarction and establishes U0126 as a promising therapeutic target.

Cognitive impairment in young and middle-aged patients with acute heart failure

AIMS

This study aimed to investigate the prevalence, risk factors and prognostic implications of cognitive impairment in young and middle-aged patients with acute heart failure (HF).

METHODS

In a prospective cohort of patients with acute HF, we assessed cognitive function by the Mini-Cog, predictors of the cognitive impairment and its associations with 30 day and 1 year cardiovascular death or HF rehospitalization among young and middle-aged patients (<65 years old).

RESULTS

Among 1958 young and middle-aged patients, the prevalence of cognitive impairment was 19.6%. Predictors of cognitive impairment included older age, females, lower education levels and prior strokes. Compared with patients having normal cognitive function, cognitive impairment was associated with a higher risk of 30 day cardiovascular death or HF rehospitalization [hazard ratio (HR), 1.52, 95% confidence interval (CI), 1.07-2.17, P = 0.02], but not for 1 year cardiovascular death or HF rehospitalization (HR, 1.06, 95% CI, 0.87-1.30, P = 0.55).

CONCLUSIONS

Cognitive impairment is present in a notable proportion of young and middle-aged patients with acute HF and is associated with an increased risk of short-term adverse outcomes. Strategies for screening and intervention for cognitive impairment at a younger age are necessary, particularly for those at high risk.

Covert Cerebrovascular Changes in People With Heart Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

To determine the prevalence of silent brain infarction (SBI) and cerebral small vessel disease (CSVD) in adults with atrial fibrillation (AF), coronary artery disease, heart failure or cardiomyopathy, heart valve disease, and patent foramen ovale (PFO), with comparisons between those with and without recent stroke and an exploration of associations between heart disease and SBI/CSVD.

METHODS

Medline, Embase, and Cochrane Library were systematically searched for hospital-based or community-based studies reporting SBI/CSVD in people with heart disease. Data were extracted from eligible studies. Outcomes were SBI (primary) and individual CSVD subtypes. Summary prevalence (95% confidence intervals [CIs]) were obtained using random-effects meta-analysis. Pooled prevalence ratios (PRs) (95% CI) were calculated to compare those with heart disease with available control participants without heart disease from studies.

RESULTS

A total of 221 observational studies were included. In those with AF, the prevalence was 36% (31%-41%) for SBI (70 studies, N = 13,589), 25% (19%-31%) for lacune (26 studies, N = 7,172), 62% (49%-74%) for white matter hyperintensity/hypoattenuation (WMH) (34 studies, N = 7,229), and 27% (24%-30%) for microbleed (44 studies, N = 13,654). Stratification by studies where participants with recent stroke were recruited identified no differences in the prevalence of SBI across subgroups (phomogeneity = 0.495). Results were comparable across participants with different heart diseases except for those with PFO, in whom there was a lower prevalence of SBI [21% (13%-30%), 11 studies, N = 1,053] and CSVD. Meta-regressions after pooling those with any heart disease identified associations of increased (study level) age and hypertensives with more SBIs and WMH (pregression <0.05). There was no evidence of a difference in the prevalence of microbleed between those with and without heart disease (PR [95% CI] 1.1 [0.7-1.7]), but a difference was seen in the prevalence of SBI and WMH (PR [95% CI] 2.3 [1.6-3.1] and 1.7 [1.1-2.6], respectively).

DISCUSSION

People with heart disease have a high prevalence of SBI (and CSVD), which is similar in those with vs without recent stroke. More research is required to assess causal links and implications for management.

TRIAL REGISTRATION INFORMATION

PROSPERO CRD42022378272 (crd.york.ac.uk/PROSPERO/).

Computerized Cognitive Training and 24-Month Mortality in Heart Failure

BACKGROUND

Cognitive dysfunction predicts mortality in heart failure (HF). Computerized cognitive training (CCT) has shown preliminary efficacy in improving cognitive function. However, the relationship between CCT and mortality is unclear. Aims were to evaluate (1) long-term efficacy of CCT in reducing 24-month mortality and (2) age, HF severity, global cognition, memory, working memory, depressive symptoms, and health-related quality of life as predictors of 24-month mortality among patients with HF.

METHODS

In this prospective longitudinal study, 142 patients enrolled in a 3-arm randomized controlled trial were followed for 24 months. Logistic regression was used to achieve the aims.

RESULTS

Across 24 months, 16 patients died (CCT, 8.3%; control groups, 12.8%). Computerized cognitive training did not predict 24-month mortality (odds ratio [OR], 0.65). Older age (OR, 1.08), worse global cognition (OR, 0.73), memory (OR, 0.81), and depressive symptoms (OR, 1.10) at baseline predicted 24-month mortality.

CONCLUSIONS

Efficacious interventions are needed to improve global cognition, memory, and depressive symptoms and reduce mortality in HF.

Cognitive Impairment in Heart Failure: A Heart Failure Society of America Scientific Statement

Cognitive impairment is common among adults with heart failure (HF), as both diseases are strongly related to advancing age and multimorbidity (including both cardiovascular and noncardiovascular conditions). Moreover, HF itself can contribute to alterations in the brain. Cognition is critical for a myriad of self-care activities that are necessary to manage HF, and it also has a major impact on prognosis; consequently, cognitive impairment has important implications for self-care, medication management, function and independence, and life expectancy. Attuned clinicians caring for patients with HF can identify clinical clues present at medical encounters that suggest cognitive impairment. When present, screening tests such as the Mini-Cog, and consideration of referral for comprehensive neurocognitive testing may be indicated. Management of cognitive impairment should focus on treatment of underlying causes of and contributors to cognitive impairment, medication management/optimization, and accommodation of deficiencies in self-care. Given its implications on care, it is important to integrate cognitive impairment into clinical decision making. Although gaps in knowledge and challenges to implementation exist, this scientific statement is intended to guide clinicians in caring for and meeting the needs of an increasingly complex and growing subpopulation of patients with HF.

Cognitive impairment in heart failure patients: association with abnormal circadian blood pressure rhythm: a review from the HOPE Asia Network

Cognitive impairment (CI) is frequently a comorbid condition in heart failure (HF) patients, and is associated with increased cardiovascular events and death. Numerous factors contribute to CI in HF patients. Decreased cerebral blood flow, inflammation, and activation of neurohumoral factors are all thought to be factors that exacerbate CI. Hypoperfusion of the brain due to decreased systemic blood flow, cerebral venous congestion, and atherosclerosis are the main mechanism of CI in HF patients. Abnormal circadian BP rhythm is one of the other conditions associated with CI. The conditions in which BP does not decrease sufficiently or increases during the night are called non-dipper or riser BP patterns. Abnormal circadian BP rhythm worsens CI in HF patients through cerebral congestion during sleep and atherosclerosis due to pressure overload. Interventions for CI in HF patients include treatment for HF itself using cardiovascular drugs, and treatment for fluid retention, one of the causes of abnormal circadian rhythms. Proposed pathways of cognitive impairment in heart failure through abnormal circadian blood pressure rhythm.

Cerebral hypometabolism mediates the effect of stroke volume on cognitive impairment in heart failure patients

AIMS

The present study aimed to phenotype the cerebral structural and glucose metabolic alterations in patients with heart failure (HF) using simultaneous positron emission tomography (PET)/magnetic resonance (MR) and to investigate their relationship to cardiac biomarkers and cognitive performance.

METHODS AND RESULTS

Forty-two HF patients caused by ischaemic heart disease (mean age 67.2 ± 10.4, 32 males) and 32 age- and sex-matched healthy volunteers (mean age 61.3 ± 4.8, 18 males) were included in this study. Participants underwent simultaneous cerebral fluorine-18 (18 F) fluorodeoxyglucose PET/MR followed by cardiac MR scan, and neuropsychological scores were obtained to assess cognitive performance. The grey matter volume (GMV) and standardized uptake value ratio (SUVR) were calculated to examine cerebral structural and metabolic alterations. Cardiac biomarkers included cardiac MR parameters and cardiac serum laboratory tests. Mediation analysis was performed to explore the associations among cerebral alterations, cardiac biomarkers, and cognitive performance. HF patients demonstrated notable cognitive impairment compared with normal controls (P < 0.001). Furthermore, HF patients exhibited regional brain hypometabolism in the bilateral calcarine cortex, caudate nucleus, thalamus, hippocampus, precuneus, posterior cingulate cortex, lingual and olfactory cortex, and GMV reduction in bilateral thalamus and hippocampus (cluster level at P < 0.05, Gaussian random field correction). The SUVR of the hypometabolic brain regions was correlated with the Montreal Cognitive Assessment (MoCA) scores (r = 0.55, P = 0.038) and cardiac stroke volume (r = 0.49, P = 0.002). Cerebral hypometabolism played a key role in the relationship between the decreased stroke volume and MoCA scores, with a mediation effect of 33.2%.

CONCLUSIONS

HF patients suffered cerebral metabolic and structural alterations in regions associated with cognition. The observed correlation between cardiac stroke volume and cognitive impairment underscored the potential influence of cerebral hypometabolism, suggesting that cerebral hypometabolism due to chronic systemic hypoperfusion may significantly contribute to cognitive impairment in HF patients.

Heart failure-induced brain myelin changes and differences between sexes

Heart failure (HF) leads to brain injury in autonomic, respiratory, mood, and cognitive control sites, revealed as tissue volume loss, altered metabolites, and impaired diffusion tissue properties. The extent of myelin changes in HF and variations within sexes are unclear. Our aim was to examine regional brain subcortical and white matter myelin integrity in HF patients over control subjects, as well as differences between sexes using T1- and T2-weighted clinical images. We acquired T1- and T2-weighted images from 63 HF patients and 129 controls using a 3.0-Tesla MRI scanner. Using T1- and T2-weighted images, ratio maps were computed, normalized to a common space, smoothed, and compared between groups (ANCOVA; covariates: age and sex; SPM12, false discovery rate, p < .010), as well as between male versus female HF (ANCOVA; covariate: age; SPM12, uncorrected p < .005). Multiple brain areas in HF showed decreased myelin integrity, including the amygdala, hippocampus, cingulate, insula, cerebellum, prefrontal cortices, and multiple white matter areas, compared to controls. Female HF patients showed more brain injuries in the parietal, prefrontal and frontal, hippocampus, amygdala, pons, cerebellar, insula, and corpus callosum compared to male HF patients. HF subjects showed compromised subcortical and white matter myelin integrity, especially in sites regulating autonomic, respiratory, mood, and cognition, with more changes in females over males. These findings provide a structural basis for the enhanced symptoms identified in female over male HF patients with similar disease severity.

Internal carotid artery blood flow and pulsatility index in cognitively impaired people with chronic heart failure

AIMS

Mild cognitive impairment and dementia are common and serious co-morbidities in people with chronic heart failure (HF) as they increase hospitalization rates, mortality and health care costs. Upon other factors, dysregulated cerebral perfusion might contribute to brain pathology. We aimed to evaluate the association of non-invasively measured blood flow (BF) and pulsatility index (PI) of the internal carotid artery (ICA) with (i) chronic HF parameters, (ii) brain morphologic measures and (iii) cognitive impairment.

METHODS AND RESULTS

This post-hoc analysis of the observational, prospective Cognition.Matters-HF study included 107 chronic HF patients without atrial fibrillation or carotid artery stenosis (aged 63 ± 10 years; 19% women). Using extracranial sonography, we measured ICA-BF and ICA-PI 1.5 cm distal of the carotid bifurcation. Brain magnetic resonance imaging was performed on a 3-Tesla scanner to quantify cerebral atrophy, hippocampal atrophy and white matter hyperintensities. Extensive neuropsychological testing tested the cognitive domains intensity of attention, visual/verbal memory and executive function (including its subdomains selectivity of attention, visual/verbal fluency and working memory) using a comprehensive test battery. (i) Neither ICA-BF (median 630 (quartiles 570, 700) mL/min) nor ICA-PI (1.05 (0.96. 1.23)) related to left ventricular ejection fraction, left atrial volume index or NT-proBNP. (ii) Higher ICA-PI (r = 0.25; P = 0.011), but not ICA-BF (r = 0.08; P = 0.409), associated with increased volume of white matter hyperintensities beyond ageing, while neither ICA-PI nor ICA-BF related to cerebral or hippocampal atrophy indices. (iii) ICA-BF, but not ICA-PI, positively correlated with age-adjusted T-scores of executive function (r = 0.38; P < 0.001) and its subdomains working memory (r = 0.32; P < 0.001) and visual/verbal fluency (r = 0.32; P < 0.001). In a multivariate linear model of executive function, only ICA-BF (T = 3.79; P < 0.001), but not HF or magnetic resonance imaging parameters, remained a significant correlate of executive function.

CONCLUSIONS

ICA-BF and ICA-PI, measured in broadly available extracranial sonography, independently related to measures of functional and structural brain changes in people with chronic HF, respectively. Due to limitations of this cross-sectional approach without a healthy control group, larger controlled longitudinal studies are needed to further elucidate the role of ICA-BF dysregulation and its implication for clinical care in this vulnerable cohort.

CaMKIIα neurons in the anterior insular cortex regulate attention behavior in mice

Introduction

The insular cortex is involved in multiple physiological processes including working memory, pain, emotion, and interoceptive functions. Previous studies have indicated that the anterior insular cortex (aIC) also mediates interoceptive attention in humans. However, the exact cellular and physiological function of the aIC in the regulation of this process is still elusive.

Methods

In this study, using the 5-choice serial reaction time task (5-CSRTT) testing paradigm, we assessed the role of the aIC in visuospatial attention and impulsiveness in mice.

Results

The results showed a dramatic activation of c-Fos in the aIC CaMKIIα neurons after the 5-CSRTT procedure. In vivo fiber photometry revealed enhanced calcium signaling in aIC CaMKIIα neurons when the mice responded correctly. In addition, chemogenetic suppression of aIC CaMKIIα neurons led to increased incorrect responses within the appropriate time. Importantly, pharmacological activation of aIC CaMKIIα neurons enhanced their performance in the 5-CSRTT test.

Discussion

These results provide compelling evidence that aIC CaMKIIα neurons are essential for the modulation of attentional processing in mice.

Reduced basal macrovascular and microvascular cerebral blood flow in young adults with metabolic syndrome: potential mechanisms

Ninety-million Americans suffer metabolic syndrome (MetSyn), increasing the risk of diabetes and poor brain outcomes, including neuropathology linked to lower cerebral blood flow (CBF), predominantly in anterior regions. We tested the hypothesis that total and regional CBF is lower in MetSyn more so in the anterior brain and explored three potential mechanisms. Thirty-four controls (25 ± 5 yr) and 19 MetSyn (30 ± 9 yr), with no history of cardiovascular disease/medications, underwent four-dimensional flow magnetic resonance imaging (MRI) to quantify macrovascular CBF, whereas arterial spin labeling quantified brain perfusion in a subset (n = 38/53). Contributions of cyclooxygenase (COX; n = 14), nitric oxide synthase (NOS, n = 17), or endothelin receptor A signaling (n = 13) were tested with indomethacin, NG-monomethyl-L-arginine (L-NMMA), and Ambrisentan, respectively. Total CBF was 20 ± 16% lower in MetSyn (725 ± 116 vs. 582 ± 119 mL/min, P < 0.001). Anterior and posterior brain regions were 17 ± 18% and 30 ± 24% lower in MetSyn; reductions were not different between regions (P = 0.112). Global perfusion was 16 ± 14% lower in MetSyn (44 ± 7 vs. 36 ± 5 mL/100 g/min, P = 0.002) and regionally in frontal, occipital, parietal, and temporal lobes (range 15-22%). The decrease in CBF with L-NMMA (P = 0.004) was not different between groups (P = 0.244, n = 14, 3), and Ambrisentan had no effect on either group (P = 0.165, n = 9, 4). Interestingly, indomethacin reduced CBF more in Controls in the anterior brain (P = 0.041), but CBF decrease in posterior was not different between groups (P = 0.151, n = 8, 6). These data indicate that adults with MetSyn exhibit substantially reduced brain perfusion without regional differences. Moreover, this reduction is not due to loss of NOS or gain of ET-1 signaling but rather a loss of COX vasodilation.NEW & NOTEWORTHY We tested the impact of insulin resistance (IR) on resting cerebral blood flow (CBF) in adults with metabolic syndrome (MetSyn). Using MRI and research pharmaceuticals to study the role of NOS, ET-1, or COX signaling, we found that adults with MetSyn exhibit substantially lower CBF that is not explained by changes in NOS or ET-1 signaling. Interestingly, adults with MetSyn show a loss of COX-mediated vasodilation in the anterior but not posterior circulation.

The pathophysiology of cognitive impairment in individuals with heart failure: a systematic review

Introduction

Heart Failure and Cognitive Impairment are both on the rise and shown to be interlinked. Despite existing reviews delineating a relationship between heart failure and cognitive impairment, the underlying pathophysiology is not researched in great depth. Current literature proposed varying pathophysiological mechanisms and focused heavily on the prevalence of cognitive impairment and treatment interventions such as cardiac rehabilitation. In view of the limitations of previous reviews, this systematic review summarized the best existing evidence concerning different pathophysiological mechanisms behind cognitive impairment in individuals with heart failure.

Methods

Eight electronic databases including PubMed, Cochrane Library and EMBASE etc., two grey literatures (ProQuest Theses and Dissertations and Mednar) and hand-searching of references were performed using specific criteria regarding population, exposures and outcomes, before duplicate removal and screening using Endnote and Rayyan respectively. JBI critical appraisal tools for non-randomized studies were used for appraisal. Data extraction was performed using two modified forms from JBI Manual for Evidence Synthesis.

Results

Narrative synthesis was performed to summarize the data from 32 studies. There were three main themes-cognitive impairment due to changes in the brain: brain atrophy, alterations in grey matter and white matter, cerebral alterations, pathway or axis changes, neuroinflammation and hippocampal gene changes; cognitive impairment due to changes in the heart or systemic circulation: inflammation, oxidative stress and changes in serum biomarkers or proteins and the riser rhythm; cognitive impairment due to changes in both the brain and the heart, with seven studies obtaining negative results. There are some limitations such as having non-human studies and large numbers of cross-sectional studies etc.

Discussion

Considering the findings, future research should examine the bi-directional relationship between the brain and the heart as most of the existing research is about the effect of the heart on the brain. By understanding the different pathophysiological mechanisms, the management and prognosis of heart failure patients will be ameliorated. Interventions that slow down or even reverse cognitive impairment can be explored so that these two common issues will not add to the already aggravating disease burden.

Systematic Review Registration

This review is registered under PROSPERO. Identifier: CRD42022381359.

Heart failure and cognitive impairment: A narrative review of neuroimaging mechanism from the perspective of brain MRI

Both heart failure (HF) and cognitive impairment (CI) have a significant negative impact on the health of the elderly individuals. Magnetic resonance imaging (MRI) can non-invasively detect functional and structural variations in the heart and brain, making it easier to explore the connection between the heart and brain. According to neuroimaging studies, HF patients have a higher chance of developing CI because they have a variety of different types of brain injuries. To examine how HF and CI are influenced by one another, English-language literature was searched in the Web of Science, PubMed EMBASE (OVID), PsycInfo, and Scopus databases. The search terms included “high-frequency,” “brain function,” “brain injury,” “cognition,” “cognitive impairment,” and “magnetic resonance imaging.” Normal brain function is typically impaired by HF in the form of decreased cerebral perfusion pressure, inflammation, oxidative stress, and damage to the BBB, resulting in CI and subsequent HF. Early pathophysiological alterations in patients’ brains have been widely detected using a range of novel MRI techniques, opening up new avenues for investigating the connection between HF and CI. This review aims to describe the pathogenesis of HF with CI and the early diagnostic role of MRI in the heart-brain domain.

Acute beetroot juice consumption does not alter cerebral autoregulation or cardiovagal baroreflex sensitivity during lower-body negative pressure in healthy adults

Introduction

Beetroot juice (BRJ) improves peripheral endothelial function and vascular compliance, likely due to increased nitric oxide bioavailability. It is unknown if BRJ alters cerebrovascular function and cardiovagal baroreflex control in healthy individuals.

Purpose

We tested the hypotheses that BRJ consumption improves cerebral autoregulation (CA) and cardiovagal baroreflex sensitivity (cBRS) during lower-body negative pressure (LBNP).

Methods

Thirteen healthy adults (age: 26 ± 4 years; 5 women) performed oscillatory (O-LBNP) and static LBNP (S-LBNP) before (PRE) and 3 h after consuming 500 mL of BRJ (POST). Participants inhaled 3% CO2 (21% O2, 76% N2) during a 5 min baseline and throughout LBNP to attenuate reductions in end-tidal CO2 tension (PETCO2). O-LBNP was conducted at ∼0.02 Hz for six cycles (-70 mmHg), followed by a 3-min recovery before S-LBNP (-40 mmHg) for 7 min. Beat-to-beat middle cerebral artery blood velocity (MCAv) (transcranial Doppler) and blood pressure were continuously recorded. CA was assessed using transfer function analysis to calculate coherence, gain, and phase in the very-low-frequency (VLF; 0.020-0.070 Hz) and low-frequency bands (LF; 0.07-0.20 Hz). cBRS was calculated using the sequence method. Comparisons between POST vs. PRE are reported as mean ± SD.

Results

During O-LBNP, coherence VLF was greater at POST (0.55 ± 0.06 vs. 0.46 ± 0.08; P < 0.01), but phase VLF (P = 0.17) and gain VLF (P = 0.69) were not different. Coherence LF and phase LF were not different, but gain LF was lower at POST (1.03 ± 0.20 vs. 1.12 ± 0.30 cm/s/mmHg; P = 0.05). During S-LBNP, CA was not different in the VLF or LF bands (all P > 0.10). Up-cBRS and Down-cBRS were not different during both LBNP protocols.

Conclusion

These preliminary data indicate that CA and cBRS during LBNP in healthy, young adults is largely unaffected by an acute bolus of BRJ.

Altered brain networks and connections in chronic heart failure patients complicated with cognitive impairment

Objective

Accumulating evidence shows that cognitive impairment (CI) in chronic heart failure (CHF) patients is related to brain network dysfunction. This study investigated brain network structure and rich-club organization in chronic heart failure patients with cognitive impairment based on graph analysis of diffusion tensor imaging data.

Methods

The brain structure networks of 30 CHF patients without CI and 30 CHF patients with CI were constructed. Using graph theory analysis and rich-club analysis, changes in global and local characteristics of the subjects' brain network and rich-club organization were quantitatively calculated, and the correlation with cognitive function was analyzed.

Results

Compared to the CHF patients in the group without CI group, the CHF patients in the group with CI group had lower global efficiency, local efficiency, clustering coefficient, the small-world attribute, and increased shortest path length. The CHF patients with CI group showed lower nodal degree centrality in the fusiform gyrus on the right (FFG.R) and nodal efficiency in the orbital superior frontal gyrus on the left (ORB sup. L), the orbital inferior frontal gyrus on the left (ORB inf. L), and the posterior cingulate gyrus on the right (PCG.R) compared with CHF patients without CI group. The CHF patients with CI group showed a smaller fiber number of edges in specific regions. In CHF patients with CI, global efficiency, local efficiency and the connected edge of the orbital superior frontal gyrus on the right (ORB sup. R) to the orbital middle frontal gyrus on the right (ORB mid. R) were positively correlated with Visuospatial/Executive function. The connected edge of the orbital superior frontal gyrus on the right to the orbital inferior frontal gyrus on the right (ORB inf. R) is positively correlated to attention/calculation. Compared with the CHF patients without CI group, the connection strength of feeder connection and local connection in CHF patients with CI group was significantly reduced, although the strength of rich-club connection in CHF patients complicated with CI group was decreased compared with the control, there was no statistical difference. In addition, the rich-club connection strength was related to the orientation (direction force) of the Montreal cognitive assessment (MoCA) scale, and the feeder and local connection strength was related to Visuospatial/Executive function of MoCA scale in the CHF patients with CI.

Conclusion

Chronic heart failure patients with CI exhibited lower global and local brain network properties, reduced white matter fiber connectivity, as well as a decreased strength in local and feeder connections in key brain regions. The disrupted brain network characteristics and connectivity was associated with cognitive impairment in CHF patients. Our findings suggest that impaired brain network properties and decreased connectivity, a feature of progressive disruption of brain networks, predict the development of cognitive impairment in patients with chronic heart failure.

Abnormalities of hippocampus and frontal lobes in heart failure patients and animal models with cognitive impairment or depression: A systematic review

AIMS

This systematic review aimed to study the hippocampal and frontal changes of heart failure (HF) patients and HF animal models with cognitive impairment or depression.

METHODS

A systematic review of the literature was conducted independently by reviewers using PubMed, Web of Science, Embase, and the Cochrane Library databases.

RESULTS AND CONCLUSIONS

30 studies were included, involving 17 pieces of clinical research on HF patients and 13 studies of HF animal models. In HF patients, the hippocampal injuries were shown in the reduction of volume, CBF, glucose metabolism, and gray matter, which were mainly observed in the right hippocampus. The frontal damages were only in reduced gray matter and have no difference between the right and left sides. The included HF animal model studies were generalized and demonstrated the changes in inflammation and apoptosis, synaptic reduction, and neurotransmitter disorders in the hippocampus and frontal lobes. The results of HF animal model studies complemented the clinical observations by providing potential mechanistic explanations of the changes in the hippocampus and frontal lobes.

Restoring myocardial infarction-induced long-term memory impairment by targeting the cystic fibrosis transmembrane regulator

BACKGROUND

Cognitive impairment is a serious comorbidity in heart failure patients, but effective therapies are lacking. We investigated the mechanisms that alter hippocampal neurons following myocardial infarction (MI).

METHODS

MI was induced in male C57Bl/6 mice by left anterior descending coronary artery ligation. We utilised standard procedures to measure cystic fibrosis transmembrane regulator (CFTR) protein levels, inflammatory mediator expression, neuronal structure, and hippocampal memory. Using in vitro and in vivo approaches, we assessed the role of neuroinflammation in hippocampal neuron degradation and the therapeutic potential of CFTR correction as an intervention.

FINDINGS

Hippocampal dendrite length and spine density are reduced after MI, effects that associate with decreased neuronal CFTR expression and concomitant microglia activation and inflammatory cytokine expression. Conditioned medium from lipopolysaccharide-stimulated microglia (LCM) reduces neuronal cell CFTR protein expression and the mRNA expression of the synaptic regulator post-synaptic density protein 95 (PSD-95) in vitro. Blocking CFTR activity also down-regulates PSD-95 in neurons, indicating a relationship between CFTR expression and neuronal health. Pharmacologically correcting CFTR expression in vitro rescues the LCM-mediated down-regulation of PSD-95. In vivo, pharmacologically increasing hippocampal neuron CFTR expression improves MI-associated alterations in neuronal arborisation, spine density, and memory function, with a wide therapeutic time window.

INTERPRETATION

Our results indicate that CFTR therapeutics improve inflammation-induced alterations in hippocampal neuronal structure and attenuate memory dysfunction following MI.

FUNDING

Knut and Alice Wallenberg Foundation [F 2015/2112]; Swedish Research Council [VR; 2017-01243]; the German Research Foundation [DFG; ME 4667/2-1]; Hjärnfonden [FO2021-0112]; The Crafoord Foundation; Åke Wibergs Stiftelse [M19-0380], NMMP 2021 [V2021-2102]; the Albert Påhlsson Research Foundation; STINT [MG19-8469], Lund University; Canadian Institutes of Health Research [PJT-153269] and a Heart and Stroke Foundation of Ontario Mid-Career Investigator Award.

Neurometabolism and Ventricular Dyssynchrony in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND

The brain coordinates the heart through the autonomic nervous system (ANS). Numerous mediator signals along the brain-heart axis interact with the neuronal-metabolic system in heart failure (HF). Disturbances in cardio-neural interactions influence the disease progression in patients with HF.

OBJECTIVES

The purpose of this study was to investigate the interactome between ANS-associated neurometabolism and ventricular dyssynchrony in patients with heart failure with reduced ejection fraction (HFrEF). Further, we studied the association of neurometabolism with major arrhythmic events (MAEs).

METHODS

A total of 197 patients with HFrEF who underwent gated single-photon emission computed tomography myocardial perfusion imaging and the brain ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography were prospectively enrolled. Relationships between the brain metabolism and MAEs were assessed using Cox models and mediation analyses. Finally, metabolic central autonomic networks were constructed and statistically compared between patients with and without MAEs.

RESULTS

In total, 35 (17.8%) patients experienced MAEs during a median follow-up of 3.1 years. In patients with HFrEF (age 58 years [IQR: 50-64 years], left ventricular ejection fraction: 20.0% [IQR: 15.0%-25.0%]), glucose hypometabolism in the insula, hippocampus, amygdala, cingulate gyrus, and caudate nucleus were independent predictors for MAEs (all P < 0.05). Cerebral hypometabolism was related to ventricular dyssynchrony, which was the predominant risk factor of MAEs. Additionally, patients who experienced MAEs presented hypoconnectivity in the metabolic central autonomic network compared with those without MAEs (P < 0.05).

CONCLUSIONS

We found an interaction of the neuronal metabolic-ventricular dyssynchronization axis in HF, which might be related to MAEs. This new brain-heart axis could expand our understanding of the distinct pathomechanisms of HFrEF.

Aberrant amplitude of low-frequency fluctuations in different frequency bands and changes after one-night positive airway pressure treatment in severe obstructive sleep apnea

Objective

This study was aimed to investigate the characteristics of the amplitude of low-frequency fluctuation (ALFF) at specific frequencies in severe obstructive sleep apnea (OSA) patients. A comparison was made between pre-CPAP treatment and one night after continuous positive airway pressure (CPAP) treatment.

Methods

30 severe OSA patients and 19 healthy controls (HC) were recruited. The ALFF method was used to assess the local features of spontaneous brain activity and calculated at different bands (slow-5 and slow-4). A correlation analysis was performed to evaluate the relationship between the changes of the ALFF and polysomnography data.

Results

Compared with HC, in slow-5 frequency band, OSA patients showed significantly decreased ALFF in the left inferior temporal gyrus, and significantly increased ALFF in the left middle frontal gyrus, left inferior frontal gyrus, triangular part, right superior frontal gyrus, dorsolateral and right middle temporal gyrus. In slow-4 frequency, there was significantly decreased ALFF in the right inferior temporal gyrus, and significantly increased ALFF in the left precuneus, right posterior cingulate gyrus and right median cingulate besides the slow-5 difference band showed. Compared with pre-CPAP, we found that after CPAP treatment, ALFF signals in the left insula in slow-5 and left caudate in slow-4 increased, but the calcarine in slow-4 significantly reduced. Correlation analysis showed that the left angular slow-4 band change was positively correlated with the slow wave sleep change (r = 0.4933, p = 0.0056). The left cerebellum 6 slow-5 band change was positively correlated with the duration of the REM sleep change (r = 0.4563, p = 0.0113), and the left cerebellum 6 slow-4 band change was also positively correlated with the mean blood oxygen change in the REM (r = 0.4591, p = 0.0107) and NREM sleep (r = 0.4492, p = 0.0128).

Conclusion

We found that the use of slow-4 was more specific in OSA studies. These results suggested that the severe OSA patients have frequency-related abnormal spontaneous neural activity, which may contribute to a better understanding of the pathological basis of OSA-related diseases and provide a potential therapeutic target for OSA patients.

The Relationship Between Pre-existing Coronary Heart Disease and Cognitive Impairment Is Partly Explained by Reduced Left Ventricular Ejection Fraction in the Subjects Without Clinical Heart Failure: A Cross-Sectional Study

Background

Coronary heart disease (CHD) is closely associated with cognitive impairment, especially in severe cases of heart failure. However, it is unclear whether cardiac systolic function plays a role in the relationship between pre-existing CHD and cognitive impairment in subjects without clinical heart failure.

Methods

In total, 208 subjects from the First Affiliated Hospital of Xi’an Jiaotong University were recruited from June 2014 to January 2015, and were divided into CHD (n = 118) and non-CHD (n = 90) groups according to the inclusion and exclusion criteria. The global cognitive function of all subjects was assessed by the Mini-Mental State Examination (MMSE) and cognitive impairment was defined as the score lower than the cutoff value. Left ventricular ejection fraction (LVEF) was measured using transthoracic echocardiograms. The relationship among pre-existing CHD, LVEF, and cognitive impairment was analyzed by multivariate logistic regression.

Results

In total, 34 subjects met the criteria of cognitive impairment. Univariate analysis showed that the cognitive impairment prevalence in the CHD group was significantly higher than that in the non-CHD group (22.0 vs. 8.9%, p = 0.011). Multivariate logistic analysis revealed that CHD was significantly associated with a higher risk of cognitive impairment (odds ratio [OR] = 3.284 [95% CI, 1.032–10.450], p = 0.044) after adjusting for confounds except for LVEF. However, the OR of CHD decreased (OR = 2.127 [95% CI, 0.624–7.254], p = 0.228) when LVEF was further corrected as a continuous variable, and LVEF was negatively associated with the risk of cognitive impairment (OR = 0.928 [95% CI, 0.882–0.976], p = 0.004).

Conclusion

Pre-existing CHD is associated with a higher risk of cognitive impairment, and such an association can be considerably explained by reduced LVEF. An impaired cardiac systolic function may play a key role in the relationship between CHD and cognitive impairment among patients with pre-heart failure conditions.

Assessment of cerebral glucose metabolism in patients with heart failure by 18F-FDG PET/CT imaging

BACKGROUND

To evaluate the cerebral metabolism in patients with heart failure (HF).

METHODS

One hundred and two HF patients were prospectively enrolled, who underwent gated 99mTc-sestamibi single photon emission computed tomography (SPECT)/CT, cardiac and cerebral 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT. Fifteen healthy volunteers served as controls. Patients were stratified by extent of hibernating myocardium (HM) and left ventricular ejection fraction (LVEF) into 4 groups where Group1: HM < 10% (n = 33); Group2: HM ≥ 10%, LVEF < 25% (n = 34); Group3: HM ≥ 10%, 25% ≤ LVEF ≤ 40% (n = 16) and Group 4: LVEF > 40% (n = 19). The standardized uptake value (SUV) in the whole brain (SUVwhole-brain) and the SUV ratios (SUVR) in 24 cognition-related brain regions were determined. SUVwhole-brain and SUVRs were compared between the 4 patient groups and the healthy controls.

RESULTS

SUVwhole-brain (r = 0.245, P = 0.013) and SUVRs in frontal areas, hippocampus, and para-hippocampus (r: 0.213 to 0.308, all P < 0.05) were correlated with HM. SUVwhole-brain differed between four patient groups and the healthy volunteers (P = 0.016) and SUVwhole-brain in Group 1 was lower than that in healthy volunteers (P < 0.05). SUVRs of Group 3 in frontal areas were the highest among four patient subgroups (P < 0.05).

CONCLUSIONS

Cerebral metabolism in the whole brain was reduced but maintained in cognition-related frontal areas in HF patients with HM and moderately impaired global left ventricular function.

Cerebral venous congestion exacerbates cerebral microhemorrhages in mice

Cerebral microhemorrhages (CMHs; microbleeds), which are small focal intracerebral hemorrhages, importantly contribute to the pathogenesis of cognitive decline and dementia in older adults. Although recently it has been increasingly recognized that the venous side of the cerebral circulation likely plays a fundamental role in the pathogenesis of a wide spectrum of cerebrovascular and brain disorders, its role in the pathogenesis of CMHs has never been studied. The present study was designed to experimentally test the hypothesis that venous congestion can exacerbate the genesis of CMHs. Increased cerebral venous pressure was induced by internal and external jugular vein ligation (JVL) in C57BL/6 mice in which systemic hypertension was induced by treatment with angiotensin II plus L-NAME. Histological analysis (diaminobenzidine staining) showed that mice with JVL developed multiple CMHs. CMHs in mice with JVL were often localized adjacent to veins and venules and their morphology was consistent with venous origin of the bleeds. In brains of mice with JVL, a higher total count of CMHs was observed compared to control mice. CMHs were distributed widely in the brain of mice with JVL, including the cortical gray matter, brain stem, the basal ganglia, subcortical white matter, cerebellum, and the hippocampi. In mice with JVL, there were more CMHs predominantly in cerebral cortex, brain stem, and cerebellum than in control mice. CMH burden, defined as total CMH volume, also significantly increased in mice with JVL. Thus, cerebral venous congestion can exacerbate CMHs. These observations have relevance to the pathogenesis of cognitive impairment associated with right heart failure as well as elevated cerebral venous pressure due to jugular venous reflux in older adults.

Heart-brain interactions in cardiac and brain diseases: why sex matters

Cardiovascular disease and brain disorders, such as depression and cognitive dysfunction, are highly prevalent conditions and are among the leading causes limiting patient's quality of life. A growing body of evidence has shown an intimate crosstalk between the heart and the brain, resulting from a complex network of several physiological and neurohumoral circuits. From a pathophysiological perspective, both organs share common risk factors, such as hypertension, diabetes, smoking or dyslipidaemia, and are similarly affected by systemic inflammation, atherosclerosis, and dysfunction of the neuroendocrine system. In addition, there is an increasing awareness that physiological interactions between the two organs play important roles in potentiating disease and that sex- and gender-related differences modify those interactions between the heart and the brain over the entire lifespan. The present review summarizes contemporary evidence of the effect of sex on heart-brain interactions and how these influence pathogenesis, clinical manifestation, and treatment responses of specific heart and brain diseases.

Brain Imaging Changes and Related Risk Factors of Cognitive Impairment in Patients With Heart Failure

Background/Aims

To explore the imaging changes and related risk factors of heart failure (HF) patients with cognitive impairment (CI).

Methods

A literature search was systematically carried out in PubMed, Web of Science, Embase, and Cochrane Library. In this systematic review, important relevant information was extracted according to the inclusion and exclusion criteria. The methodological quality was assessed by three scales according to the different study types.

Results

Finally, 66 studies were included, involving 33,579 patients. In the imaging changes, the severity of medial temporal lobe atrophy (MTA) and the decrease of gray Matter (GM) volume were closely related to the cognitive decline. The reduction of cerebral blood flow (CBF) may be correlated with CI. However, the change of white matter (WM) volume was possibly independent of CI in HF patients. Specific risk factors were analyzed, and the data indicated that the increased levels of B-type natriuretic peptide (BNP)/N-terminal pro-B-type natriuretic peptide (NT-proBNP), and the comorbidities of HF, including atrial fibrillation (AF), diabetes mellitus (DM) and anemia were definitely correlated with CI in patients with HF, respectively. Certain studies had also obtained independent correlation results. Body mass index (BMI), depression and sleep disorder exhibited a tendency to be associated with CI. Low ejection fraction (EF) value (<30%) was inclined to be associated with the decline in cognitive function. However, no significant differences were noted between heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) in cognitive scores.

Conclusion

BNP/NT-proBNP and the comorbidities of HF including AF, DM and anemia were inextricably correlated with CI in patients with HF, respectively. These parameters were independent factors. The severity of MTA, GM volume, BMI index, depression, sleep disorder, and low EF value (<30%) have a disposition to associated with CI. The reduction in the CBF volume may be related to CI, whereas the WM volume may not be associated with CI in HF patients. The present systematic review provides an important basis for the prevention and treatment of CI following HF.

Cognitive Impairment in Heart Failure: Landscape, Challenges, and Future Directions

Heart failure (HF) is a major global healthcare problem accounting for substantial deterioration of prognosis. As a complex clinical syndrome, HF often coexists with multi-comorbidities of which cognitive impairment (CI) is particularly important. CI is increasing in prevalence among patients with HF and is present in around 40%, even up to 60%, of elderly patients with HF. As a potent and independent prognostic factor, CI significantly increases the hospitalization and mortality and decreases quality of life in patients with HF. There has been a growing awareness of the complex bidirectional interaction between HF and CI as it shares a number of common pathophysiological pathways including reduced cerebral blood flow, inflammation, and neurohumoral activations. Research that focus on the precise mechanism for CI in HF is still ever insufficient. As the tremendous adverse consequences of CI in HF, effective early diagnosis of CI in HF and interventions for these patients may halt disease progression and improve prognosis. The current clinical guidelines in HF have begun to emphasize the importance of CI. However, nearly half of CI in HF is underdiagnosed, and few recommendations are available to guide clinicians about how to approach CI in patients with HF. This review aims to synthesize knowledge about the link between HF and cognitive dysfunction, issues pertaining to screening, diagnosis and management of CI in patients with HF, and emerging therapies for prevention. Based on data from current studies, critical gaps in knowledge of CI in HF are identified, and future research directions to guide the field forward are proposed.

Myocardial infarction coincides with increased NOX2 and Nε-(carboxymethyl) lysine expression in the cerebral microvasculature

Background

Myocardial infarction (MI) is associated with mental health disorders, in which neuroinflammation and cerebral microvascular dysfunction may play a role. Previously, we have shown that the proinflammatory factors N^ε-(carboxymethyl)lysine (CML) and NADPH oxidase 2 (NOX2) are increased in the human infarcted heart microvasculature. The aim of this study was to analyse the presence of CML and NOX2 in the cerebral microvasculature of patients with MI.

Methods

Brain tissue was obtained at autopsy from 24 patients with MI and nine control patients. According to their infarct age, patients with MI were divided into three groups: 3–6 hours old (phase I), 6 hours–5 days old (phase II) and 5–14 days old (phase III). CML and NOX2 in the microvasculature were studied through immunohistochemical analysis.

Results

We observed a 2.5-fold increase in cerebral microvascular CML in patients with phase II and phase III MI (phase II: 21.39±7.91, p=0.004; phase III: 24.21±10.37, p=0.0007) compared with non-MI controls (8.55±2.98). NOX2 was increased in microvessels in patients with phase II MI (p=0.002) and phase III MI (p=0.04) compared with controls. No correlation was found between CML and NOX2 (r=0.58, p=0.13).

Conclusions

MI coincides with an increased presence of CML and NOX2 in the brain microvasculature. These data point to proinflammatory alterations in the brain microvasculature that may underlie MI-associated mental health disorders.

Randomized Controlled Trial of a Cognitive Intervention to Improve Memory in Heart Failure

BACKGROUND

The objective of this 3-arm randomized controlled trial was to evaluate efficacy of computerized cognitive training (CCT) to improve primary outcomes of delayed recall memory and serum brain-derived neurotrophic factor (BDNF) levels and secondary outcomes of working memory, instrumental activities of daily living (IADL), and health-related quality of life (HRQL) among patients with heart failure (HF).

METHODS AND RESULTS

Patients (N = 256) were randomly assigned to 8 weeks of CCT using BrainHQ, computerized crossword puzzles active control intervention, and usual care. All patients received weekly nurse enhancement interventions. Data were collected at enrollment and baseline visits and at 10 weeks and 4 and 8 months. In mixed effects models, there were no statistically significant group or group by time differences in outcomes. There were statistically significant differences over time in all outcomes in all groups. Patients improved over time on measures of delayed recall memory, working memory, IADL, and HRQL and had decreased serum BDNF.

CONCLUSIONS

CCT did not improve outcomes compared with the active control intervention and usual care. Nurse enhancement interventions may have led to improved outcomes over time. Future studies are needed to test nurse enhancement interventions in combination with other cognitive interventions to improve memory in HF.

LAYSUMMARY

In 256 patients with heart failure, 8 weeks of computerized cognitive training, computerized crossword puzzles, or usual care were studied for effects on (1st) recall memory and serum brain-derived neurotrophic factor (BDNF) and (2nd) working memory, instrumental activities of daily living (IADL), and health-related quality of life (HRQL). Measurements were at baseline, 10 weeks, 4- and 8-months. Nurse enhancement interventions (e.g., support, assessment) were provided. Recall memory, working memory, IADL, and HRQL improved over time. There were no statistically significant differences among treatment groups over time. BDNF unexpectedly decreased. Nurse enhancement interventions may explain improved outcomes. Future studies are needed.

Nitric oxide synthase inhibition in healthy adults reduces regional and total cerebral macrovascular blood flow and microvascular perfusion

The importance of nitric oxide (NO) in regulating cerebral blood flow (CBF) remains unresolved, due in part to methodological approaches, which lack a comprehensive assessment of both global and regional effects. Importantly, NO synthase (NOS) expression and activity appear greater in some anterior brain regions, suggesting region-specific NOS influence on CBF. We hypothesized that NO contributes to basal CBF in healthy adults, in a regionally distinct pattern that predominates in the anterior circulation. Fourteen healthy adults (7 females; 24 ± 5 years) underwent two magnetic resonance imaging (MRI) study visits with saline (placebo) or the NOS inhibitor, L-NMMA, administered in a randomized, single-blind approach. 4D flow MRI quantified total and regional macrovascular CBF, whereas arterial spin labelling (ASL) MRI quantified total and regional microvascular perfusion. L-NMMA (or volume-matched saline) was infused intravenously for 5 min prior to imaging. L-NMMA reduced CBF (L-NMMA: 722 ± 100 vs. placebo: 771 ± 121 ml/min, P = 0.01) with similar relative reductions (5-7%) in anterior and posterior cerebral circulations, due in part to the reduced cross-sectional area of 9 of 11 large cerebral arteries. Global microvascular perfusion (ASL) was reduced by L-NMMA (L-NMMA: 42 ± 7 vs. placebo: 47 ± 8 ml/100g/min, P = 0.02), with 7-11% reductions in both hemispheres of the frontal, parietal and temporal lobes, and in the left occipital lobe. We conclude that NO contributes to macrovascular and microvascular regulation including larger artery resting diameter. Contrary to our hypothesis, the influence of NO on cerebral perfusion appears regionally uniform in healthy young adults. KEY POINTS: Cerebral blood flow (CBF) is vital for brain health, but the signals that are key to regulating CBF remain unclear. Nitric oxide (NO) is produced in the brain, but its importance in regulating CBF remains controversial since prior studies have not studied all regions of the brain simultaneously. Using modern MRI approaches, a drug that inhibits the enzymes that make NO (L-NMMA) reduced CBF by up to 11% in different brain regions. NO helps maintain proper CBF in healthy adults. These data will help us understand whether the reductions in CBF that occur during ageing or cardiovascular disease are related to shifts in NO signalling.

Soluble Guanylate Cyclase Stimulator Vericiguat Enhances Long-Term Memory in Rats without Altering Cerebral Blood Volume

Vascular cognitive impairment (VCI) is characterized by impairments in cerebral blood flow (CBF), endothelial function and blood-brain barrier (BBB) integrity. These processes are all physiologically regulated by the nitric oxide (NO)-soluble guanylate cyclase (sGC)-cGMP signaling pathway. Additionally, cGMP signaling plays an important role in long-term potentiation (LTP) underlying memory formation. Therefore, targeting the NO-sGC-cGMP pathway may be a therapeutic strategy for treating VCI. Hence, in this study we investigated whether sGC stimulator vericiguat has potential as a cognitive enhancer. The effects of vericiguat on long-term memory were measured in rats using an object location task. Due to the low brain-penetrance of vericiguat found in this study, it was investigated whether in the absence of BBB limitations, vericiguat enhanced hippocampal plasticity using an ex vivo memory acquisition-like chemical LTP model. Finally, peripheral effects were measured by means of blood pressure and cerebral blood volume. Vericiguat successfully enhanced long-term memory and increased hippocampal plasticity via enhanced translocation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors to the cell membrane, while blood pressure and cerebral blood volume were unaltered. Although the memory enhancing effects in this study are likely due to peripheral effects on the cerebral microvasculature, sGC stimulation may provide a new therapeutic strategy for treating VCI, especially when BBB integrity is reduced.

Dependence and reduced motor function in heart failure: future directions for well-being

While patients with heart failure experience a wide range of symptoms, evidence is mounting that patients with heart failure suffer from reduced functional independence. Given that the number of patients with heart failure is rising and considering the adverse outcomes of reduced functional independence, understanding the underlying mechanisms of reduced functionality in patients with heart failure is of increasing importance. Yet, little information exists on how heart failure negatively affects functional independence, including motor function. This article summarizes reports of reduced independence and highlights its significant adverse outcomes in the patients with heart failure. Finally, this article discusses potential causes of reduced independence based on existing reports of impaired central and peripheral nervous systems in the patients with heart failure. Overall, the article provides a solid foundation for future studies investigating motor impairments in patients with heart failure. Such studies may lead to advances in treatment and prevention of reduced independence associated with heart failure, which ultimately contribute to the well-being of patients with heart failure.

Heart failure impairs mood and memory in male rats and down-regulates the expression of numerous genes important for synaptic plasticity in related brain regions

Chronic heart failure (HF) is a serious disorder that afflicts more than 26 million patients worldwide. HF is comorbid with depression, anxiety and memory deficits that have serious implications for quality of life and self-care in patients who have HF. Still, there are few studies that have assessed the effects of severely reduced ejection fraction (≤40 %) on cognition in non-human animal models. Moreover, limited information is available regarding the effects of HF on genetic markers of synaptic plasticity in brain areas critical for memory and mood regulation. We induced HF in male rats and tested mood and anxiety (sucrose preference and elevated plus maze) and memory (spontaneous alternation and inhibitory avoidance) and measured the simultaneous expression of 84 synaptic plasticity-associated genes in dorsal (DH) and ventral hippocampus (VH), basolateral (BLA) and central amygdala (CeA) and prefrontal cortex (PFC). We also included the hypothalamic paraventricular nucleus (PVN), which is implicated in neurohumoral activation in HF. Our results show that rats with severely reduced ejection fraction recapitulate behavioral symptoms seen in patients with chronic HF including, increased anxiety and impaired memory in both tasks. HF also downregulated several synaptic-plasticity genes in PFC and PVN, moderate decreases in DH and CeA and minimal effects in BLA and VH. Collectively, these findings identify candidate brain areas and molecular mechanisms underlying HF-induced disturbances in mood and memory.

Cerebral blood flow impairment and cognitive decline in heart failure

BACKGROUND AND PURPOSE

Cognitive decline is an important contributor to disability in patients with chronic heart failure, affecting 25%-50% of patients. The aim of this review is to stress the importance of understanding pathophysiological mechanisms of heart failure involved in cognitive decline.

METHODS

An extensive PubMed search was conducted for the literature on the basic mechanisms of cerebral blood flow regulation, the effect of cardiac dysfunction on cerebral blood flow, and possible mechanisms underlying the association between cardiac dysfunction and cognitive decline.

RESULTS

Published literature supports the thesis that cardiac dysfunction leads to cerebral blood flow impairment and predisposes to cognitive decline. One of the postulated mechanisms underlying cognitive decline in chronic heart failure is chronic regional hypoperfusion of critical brain areas. Cognitive function may be further compromised by microvascular damage due to cardiovascular risk factors. Furthermore, it is implied that cerebral blood flow assessment could enable early recognition of patients at risk and help guide appropriate therapeutic strategies.

CONCLUSION

Interdisciplinary knowledge in the fields of neurology and cardiology is essential to clarify heart and brain interconnections in chronic heart failure. Understanding and identifying the basic neuropathophysiological changes in chronic heart failure could help with developing methods for early recognition of patients at risk, followed by institution of therapeutic actions to prevent or decrease cognitive decline.

Temporal changes in total and hippocampal brain volume and cognitive function in patients with chronic heart failure-the COGNITION.MATTERS-HF cohort study

Aims

We quantified the concurring dynamics affecting total and hippocampal brain volume and cognitive function in patients with chronic heart failure (HF) over a period of three years.

Methods and results

A total of 148 patients with mild stable HF entered this monocentric prospective cohort study: mean age 64.5 (10.8) years; 16.2% female; 77% in New York Heart Association functional classes I–II; 128 and 105 patients attended follow-up visits after 1 and 3 years, respectively. The assessment included cardiological, neurological, psychological work-up, and brain magnetic resonance imaging. Total and regional brain volumes were quantified using an operator-independent fully automated approach and reported normalized to the mean estimated intracranial volume. At baseline, the mean hippocampal volume was ∼13% lower than expected. However, the 3-year progressive hippocampal volume loss was small: −62 mm³ [95% confidence interval (CI) −81 to −42, P < 0.0001). This corresponded to a relative change of −1.8% (95% CI −2.3 to −1.2), which was similar in magnitude as observed with physiological aging. Moreover, the load of white matter hypointensities increased within the limits of normal aging. Cognitive function during the 3-year observation period remained stable, with ‘intensity of attention’ as the only domain declining (LSmean −1.82 points, 95% CI −3.05 to −0.58, P = 0.004). After 3 years, performance in all domains of cognition remained associated with hippocampal volume (r ≥ 0.29).

Conclusion

In patients with predominantly mild HF, the markedly reduced hippocampal volume observed at baseline was associated with impaired cognitive function, but no accelerated deterioration in cognition and brain atrophy became evident over a mid-term period of three years.

Cognitive impairment in myocardial infarction and heart failure

Myocardial infarction (MI) occurs when coronary blood flow is decreased due to an obstruction/occlusion of the vessels, leading to myocardial death and progression to heart failure (HF). Cognitive impairment, anxiety, depression and memory loss are the most frequent mental health problems among patients with HF. The most common cause of cognitive decline is cardiac systolic dysfunction, which leads to reduced cerebral perfusion. Several in vivo and clinical studies provide information regarding the underlying mechanisms of HF in brain pathology. Neurohormonal activation, oxidative stress, inflammation, glial activation, dendritic spine loss and brain programmed cell death are all proposed as contributors of cognitive impairment in HF. Furthermore, several investigations into the effects of various medications on brain pathology utilizing MI models have been reported. In this review, potential mechanisms involving HF-associated cognitive impairment, as well as neuroprotective interventions in HF models, are discussed and summarized. In addition, gaps in the surrounding knowledge, including the types of brain cell death and the effects of cell death inhibitors in HF, are presented and discussed. This review provides valuable information that will suggest the potential therapeutic strategies for cognitive impairment in patients with HF.

Assesment of Cerebral Blood Flow Velocities with Transcranial Doppler Ultrasonography in Heart Failure Patients with Reduced Ejection Fraction

BACKGROUND

Heart and brain interaction is a well-known entity in heart failure (HF) and left ventricular systolic dysfunction poses an increased risk for stroke and cognitive impairment. Transcranial Doppler (TCD) provides valuable information on cerebral blood flow velocities (CBFV). However, less is known about CBFV in HF patients with reduced EF. So, we aimed to evaluate CBFV by means of TCD in patients with HF and reduced ejection fraction (HFrEF).

METHODS

This study included 46 HFrEF patients (mean age 65.2±11 years, mean EF 20.1±3.8%) who underwent to TCD examination. In addition, 26 healthy individuals with sinus rhythm and EF >50% were included in the study as a control group. Peak systolic, mean and end diastolic flow velocities of the both right and left middle cerebral artery (RMCA and LMCA) were analyzed. In subgroup analysis, HFrEF patients compared according to rhythm. Correlation analyses was performed in HFrEF group between EF and TCD velocities.

RESULTS

The average of RMCA and LMCA peak systolic and mean flow velocities were significantly lower in HF patients than those in control group (76,06±23,7 cm/s and 48,49±16,4 cm/s in HF group vs 87,84±14,5 cm/s and 56,41±10,7 cm/s in control group, p=0,025 and p=0,016, respectively, for RMCA and 75,1±22,3 cm/s and 47,57±14.8 cm/s in HF group vs 88,73±17,7 cm/s and 57,15±12,4 cm/s in control group, p=0,009 and p=0,007, respectively, for LMCA). The average mean flow velocity of RMCA and LMCA was significantly lower in HFrEF patients with AF than HFrEF patients with sinus rhythm. (P=0.04 and P= 0.03, respectively) In correlation analysis, EF was significantly positively correlated with both LMCA and RMCA flow velocities in HFrEF group.

CONCLUSION

This study showed that HFrEF patients have lower CBFV as compared to healthy controls and HFrEF patients with AF rhythm have lower CBFV compared to HFrEF with sinus rhythm which might be one of the explanations of the adverse interaction between heart and brain in HFrEF.

Impact of Cardiovascular Hemodynamics on Cognitive Aging

[Figure: see text].

Epigenetic gene expression links heart failure to memory impairment

In current clinical practice, care of diseased patients is often restricted to separated disciplines. However, such an organ-centered approach is not always suitable. For example, cognitive dysfunction is a severe burden in heart failure patients. Moreover, these patients have an increased risk for age-associated dementias. The underlying molecular mechanisms are presently unknown, and thus, corresponding therapeutic strategies to improve cognition in heart failure patients are missing. Using mice as model organisms, we show that heart failure leads to specific changes in hippocampal gene expression, a brain region intimately linked to cognition. These changes reflect increased cellular stress pathways which eventually lead to loss of neuronal euchromatin and reduced expression of a hippocampal gene cluster essential for cognition. Consequently, mice suffering from heart failure exhibit impaired memory function. These pathological changes are ameliorated via the administration of a drug that promotes neuronal euchromatin formation. Our study provides first insight to the molecular processes by which heart failure contributes to neuronal dysfunction and point to novel therapeutic avenues to treat cognitive defects in heart failure patients.

Neuropsychological Assessment and Screening in Heart Failure: a Meta-Analysis and Systematic Review

A variety of neuropsychological changes secondary to heart failure have been documented in the literature. However, what remains unclear are which neuropsychological abilities are the most impacted by heart failure and what tests have the sensitivity to measure that impact. Eight databases were searched for articles that examined the neuropsychological functioning of patients with heart failure. Some of the inclusion criteria were articles had to have a heart failure group with a demographically comparable control group and standardized neuropsychological testing. Exclusion criteria included articles with a heart failure group with any other type of major organ failure, or comparisons that were between different classes of heart failure rather than between a heart failure and non-heart failure group. A total of 33 articles met the inclusion criteria (total heart failure sample n = 8900) and provided effect size data for 20 neuropsychological domains. All observed domain-level differences between heart failure and non-heart failure groups were statistically significant, except for simple motor functioning and confrontation naming. The greatest differences in performance were in executive functioning, global cognition, complex psychomotor speed, and verbal memory. The highest effect sizes came from Trail-Making Test-Part B, CAMCOG, Symbol Digit Modality Test, and California Verbal Learning Test. The neuropsychological patterns of heart failure suggested diffuse cognitive involvement, with higher-level processes being most affected. It is important to track neurocognition in this clinical population since neuropsychological impairment is prevalent, and screening measures appear to be reliable. Such screening and further assessment would inform future medical treatment and may improve patient care management.

Angiotensin converting enzyme inhibition improves cerebrovascular control during exercise in male rats with heart failure

We investigated the effects of chronic (∼7 weeks) treatment with the angiotensin converting enzyme (ACE) inhibitor Captopril in rats with heart failure with reduced ejection fraction (HF-rEF) on brain blood flow (BF; radiolabeled microspheres) at rest and during submaximal exercise. We hypothesized that middle cerebral, posterior cerebral, and cerebellar BF during submaximal exercise (20 m/min, 5% incline) would be reduced in rats with HF-rEF (n = 10) compared to healthy (SHAM, n = 10) controls and HF-rEF rats chronically treated with Captopril (HF-rEF + Cap., n = 20). During submaximal exercise middle cerebral (HF-rEF + Cap.: 274 ± 12; HF-rEF: 234 ± 23; SHAM: 248 ± 24 ml/min/100 g) and cerebellar (HF-rEF + Cap.: 222 ± 14; HF-rEF: 243 ± 22; SHAM: 214 ± 23 ml/min/100 g) BF increased from rest in all groups with no difference among groups (P > 0.24). Posterior cerebral BF increased from rest in all groups but was lower than SHAM (394 ± 46 ml/min/100 g; P = 0.03) in HF-rEF (298 ± 19 ml/min/100 g) but not HF-rEF + Cap. (356 ± 18 ml/min/100 g; P = 0.14), supporting the concept that ACE inhibition in HF-rEF elevates brain BF increases, at least to the posterior cerebral region, during moderate intensity exercise/physical activity.

Testing influences of APOE and BDNF genes and heart failure on cognitive function

BACKGROUND

Apolipoprotein E (APOE) ε2, ε4 and brain-derived neurotrophic factor (BDNF) Val66Met alleles have been associated with cognition. Associations of these alleles with cognition in heart failure (HF) and influences of HF across the cognitive spectrum (i.e., cognitively normal to Alzheimer's dementia [AD]) remain unexplored.

OBJECTIVES

To investigate influences of APOE ε2, ε4, BDNF Met and HF on cognition among participants across the cognitive spectrum.

METHODS

Genetic association study using national databases (N = 7,166).

RESULTS

APOE ε2 frequencies were similar across the cognitive spectrum among participants with HF. APOE ε4 frequency was lower among participants with HF and AD than non-HF participants with AD. BDNF Met frequencies did not differ across the spectrum. HF was associated with worse attention and language. In the HF subsample, ε4 was associated with worse memory.

CONCLUSION

Associations between APOE and cognition may differ in HF but need to be tested in a larger sample.

Association between Heart Failure and Clinical Prognosis in Patients with Acute Ischemic Stroke: A Retrospective Cohort Study

Background and Purpose

Ischemic stroke is a common cause of death worldwide. In clinical practice it is observed that many individuals who have experienced an ischemic stroke also suffer from simultaneous comorbidities such as heart failure, which could be directly associated with a worse clinical prognosis. Therefore, this study analyzed outcomes in terms of the severity of the event, inhospital mortality, duration of hospital stay, and inhospital recurrence of the episode, in order to determine the implications resulting from the presentation of both pathologies.

Methods

This was a retrospective-cohort, hospital-based study.

Results

The study included 110 subjects with heart failure (exposed) and 109 subjects without heart failure (nonexposed). The incidence of inhospital mortality was 27.27% in exposed patients and 9.17% in nonexposed patients (p<0.001), and the presence of heart failure increased the risk of death by 92% (p=0.027). According to scores on the National Institutes of Health Stroke Scale, the median severity was worse in exposed than nonexposed patients (16.1 vs. 9.2, p =0.001). The median hospital stay was 9 days in subjects with heart failure and 7 days in nonexposed patients (p=0.011). The rate of inhospital stroke did not differ significantly between exposed and nonexposed patients (1.82% vs. 0.92%, p=0.566).

Conclusions

Individuals with heart failure who suffer from an acute ischemic stroke show worse clinical outcomes in terms of mortality, event severity, and duration of hospital stay.

Serum neurofilament light in atrial fibrillation: clinical, neuroimaging and cognitive correlates

Emerging evidence suggests that atrial fibrillation is associated with cognitive dysfunction independently of stroke, but the underlying mechanisms remain unclear. In this cross-sectional analysis from the Swiss-atrial fibrillation Study (NCT02105844), we investigated the association of serum neurofilament light protein, a neuronal injury biomarker, with (i) the CHA₂DS₂-VASc score (congestive heart failure, hypertension, age 65–74 or >75 years, diabetes mellitus, stroke or transient ischaemic attack, vascular disease, sex), clinical and neuroimaging parameters and (ii) cognitive measures in atrial fibrillation patients. We measured neurofilament light in serum using an ultrasensitive single-molecule array assay in a sample of 1379 atrial fibrillation patients (mean age, 72 years; female, 27%). Ischaemic infarcts, small vessel disease markers and normalized brain volume were assessed on brain MRI. Cognitive testing included the Montreal cognitive assessment, trail-making test, semantic verbal fluency and digit symbol substitution test, which were summarized using principal component analysis. Results were analysed using univariable and multivariable linear regression. Neurofilament light was associated with the CHA₂DS₂-VASc score, with an average 19.2% [95% confidence interval (17.2%, 21.3%)] higher neurofilament per unit CHA₂DS₂-VASc increase. This association persisted after adjustment for age and MRI characteristics. In multivariable analyses, clinical parameters associated with neurofilament light were higher age [32.5% (27.2%, 38%) neurofilament increase per 10 years], diabetes mellitus, heart failure and peripheral artery disease [26.8% (16.8%, 37.6%), 15.7% (8.1%, 23.9%) and 19.5% (6.8%, 33.7%) higher neurofilament, respectively]. Mean arterial pressure showed a curvilinear association with neurofilament, with evidence for both an inverse linear and a U-shaped association. MRI characteristics associated with neurofilament were white matter lesion volume and volume of large non-cortical or cortical infarcts [4.3% (1.8%, 6.8%) and 5.5% (2.5%, 8.7%) neurofilament increase per unit increase in log-volume of the respective lesion], as well as normalized brain volume [4.9% (1.7%, 8.1%) higher neurofilament per 100 cm³ smaller brain volume]. Neurofilament light was inversely associated with all cognitive measures in univariable analyses. The effect sizes diminished after adjusting for clinical and MRI variables, but the association with the first principal component was still evident. Our results suggest that in atrial fibrillation patients, neuronal loss measured by serum neurofilament light is associated with age, diabetes mellitus, heart failure, blood pressure and vascular brain lesions, and inversely correlates with normalized brain volume and cognitive function.

Lower Cardiac Output Relates to Longitudinal Cognitive Decline in Aging Adults

Background

Subclinical reductions in cardiac output correspond to lower cerebral blood flow (CBF), placing the brain at risk for functional changes.

Objectives

This study aims to establish the consequences of reduced cardiac output on longitudinal cognitive outcomes in aging adults.

Methods

Vanderbilt Memory and Aging Project participants free of clinical dementia and heart failure (n = 306, 73 ± 7, 58% male) underwent baseline echocardiography to assess cardiac output (L/min) and longitudinal neuropsychological assessment at baseline, 18 months, 3 and 5 years. Linear mixed-effects regressions related cardiac output to trajectory for each longitudinal neuropsychological outcome, adjusting for age, sex, race/ethnicity, education, body surface area, Framingham Stroke Risk Profile score, apolipoprotein E (APOE) ε4 status and follow-up time. Models were repeated, testing interactions with cognitive diagnosis and APOE-ε4 status.

Results

Lower baseline cardiac output related to faster declines in language (β = 0.11, p = 0.01), information processing speed (β = 0.31, p = 0.006), visuospatial skills (β = 0.09, p = 0.03), and episodic memory (β = 0.02, p = 0.001). No cardiac output x cognitive diagnosis interactions were observed (p > 0.26). APOE-ε4 status modified the association between cardiac output and longitudinal episodic memory (β = 0.03, p = 0.047) and information processing speed outcomes (β = 0.55, p = 0.02) with associations stronger in APOE-ε4 carriers.

Conclusion

The present study provides evidence that even subtle reductions in cardiac output may be associated with more adverse longitudinal cognitive health, including worse language, information processing speed, visuospatial skills, and episodic memory performances. Preservation of healthy cardiac functioning is important for maintaining optimal brain aging among older adults.

Executive dysfunction is associated with self-care confidence in patients with heart failure

AIM

To explore differences in self-care maintenance, management and confidence levels between American heart failure (HF) patients with and without executive dysfunction.

BACKGROUND

Evidence indicates some aspect of cognitive impairment is prevalent in up to 75% of the HF patient population. Moreover, cognitive impairment has been identified as a barrier to adequate self-care contributing to poor outcomes. There is limited understanding of the role executive function, a domain of cognitive performance, has on self-care behaviors for patients with HF.

METHOD

This secondary analysis examined the role of executive function, measured by the Clock Drawing Test (CDT), in relation to self-care measures. The Self Care of Heart Failure Index v6.2 (SCHFI v6.2) was used to measure self-care maintenance, management, and confidence.

RESULTS

Participants had a mean age of 75.1 ± 12.5 years, identified as male (59.4%), with New York Heart Association (NYHA) class III (57.3%). Executive function impairment was present in 28% of the sample. Comparison of self-care maintenance and management scores between the two groups were not significant. However, participants with executive dysfunction demonstrated an average self-care confidence score of 48.6 ± 23.3, while participants with no executive function impairment demonstrated a higher average self-care confidence score of 61.5 ± 18.4. Differences in self-care confidence scores between the groups were statistically significant (p = .014).

CONCLUSIONS

HF self-care confidence is considered a moderator of self-care behaviors. Understanding the influence executive function has on self-care confidence may lead to a better understanding of those needing greater support with self-care behaviors.

18 F-FDG PET/CT brain glucose metabolism as a marker of different types of depression comorbidity in chronic heart failure patients with impaired systolic function

AIMS

Depression is an important issue in heart failure (HF). The study investigated whole-brain and regional brain glucose metabolism in HF patients and its association with depression comorbidity.

METHODS AND RESULTS

Twenty-nine hospitalized patients with symptomatic systolic HF (left ventricular ejection fraction <40%), New York Heart Association (NYHA) class II-IV and mean age of 55.5 ± 12.0 years, had psychometric questionnaires before discharge and an ¹⁸ F-FDG PET/CT brain scan after discharge. Semi-automated image analysis was performed on all cases and 30 matched controls. The metabolic parameter mean standardized uptake value (SUV_mean ) was calculated for the whole brain and three brain regions implicated in depression pathogenesis. A standardized SUV_mean was also estimated by dividing regional brain SUV_mean with whole-brain SUV_mean . Cases had lower average whole-brain SUV_mean (3.90 ± 1.49 vs. 5.10 ± 1.35, P = 0.001) and average regional brain SUV_mean (4.57 ± 2.31 vs. 9.96 ± 3.58, P < 0.001) compared to controls. Whole-brain SUV_mean had a significant correlation with patient age, NYHA class, diabetes, creatinine levels, depression, and cognitive impairment. Regional brain SUV_mean was correlated with whole-brain SUV_mean and depression. The standardized SUV_mean , in particular, was found to be a robust index that could differentiate HF patients with 'epiphenomenal' (>0.93) or 'real' (≤0.93) depression.

CONCLUSION

Heart failure patients with more severe disease showed whole-brain and regional brain hypometabolism in ¹⁸ F-FDG PET/CT. Depressed HF patients (Beck Depression Inventory score >13) exhibited different metabolic patterns that could be used to differentiate between 'epiphenomenal' and 'real' depression. Namely, presence of whole-brain hypometabolism suggested 'epiphenomenal' depression, whereas absence suggested 'real' depression. Presence of significant relative regional brain hypometabolism enhanced the likelihood of 'real' depression diagnosis.

Hemodynamic Instability in Heart Failure Intensifies Age-Dependent Cognitive Decline

This review attempts to examine two key elements in the evolution of cognitive impairment in the elderly who develop heart failure. First, major left side heart parts can structurally and functionally deteriorate from aging wear and tear to provoke hemodynamic instability where heart failure worsens or is initiated; second, heart failure is a major inducer of cognitive impairment and Alzheimer's disease in the elderly. In heart failure, when the left ventricular myocardium of an elderly person does not properly contract, it cannot pump out adequate blood to the brain, raising the risk of cognitive impairment due to the intensification of chronic brain hypoperfusion. Chronic brain hypoperfusion originates from chronically reduced cardiac output which progresses as heart failure worsens. Other left ventricular heart parts, including atrium, valves, myocardium, and aorta can contribute to the physiological shortfall of cardiac output. It follows that hemodynamic instability and perfusion changes occurring from the aging heart's blood pumping deficiency will, in time, damage vulnerable brain cells linked to specific cognitive regulatory sites, diminishing neuronal energy metabolism to a level where progressive cognitive impairment is the outcome. Could cognitive impairment progress be reversed with a heart transplant? Evidence is presented detailing the errant hemodynamic pathways leading to cognitive impairment during aging as an offshoot of inefficient structural and functional heart parts and their contribution to heart failure.

Cerebral blood flow and cognitive functioning in patients with disorders along the heart-brain axis: Cerebral blood flow and the heart-brain axis

INTRODUCTION

We examined the role of hemodynamic dysfunction in cognition by relating cerebral blood flow (CBF), measured with arterial spin labeling (ASL), to cognitive functioning, in patients with heart failure (HF), carotid occlusive disease (COD), and patients with cognitive complaints and vascular brain injury on magnetic resonance imaging (MRI; ie, possible vascular cognitive impairment [VCI]).

METHODS

We included 439 participants (124 HF; 75 COD; 127 possible VCI; 113 reference participants) from the Dutch multi-center Heart-Brain Study. We used pseudo-continuous ASL to estimate whole-brain and regional partial volume-corrected CBF. Neuropsychological tests covered global cognition and four cognitive domains.

RESULTS

CBF values were lowest in COD, followed by VCI and HF, compared to reference participants. This did not explain cognitive impairment, as we did not find an association between CBF and cognitive functioning.

DISCUSSION

We found that reduced CBF is not the major explanatory factor underlying cognitive impairment in patients with hemodynamic dysfunction along the heart-brain axis.

Danhong injection facilitates recovery of post-stroke motion deficit via Parkin-enhanced mitochondrial function

BACKGROUND

A cerebral ischemic stroke involves mitochondrial dysfunction, motor deficits, and paralysis; and Danhong injection (DHI) might possess mitochondrial protection and functional recovery in a stroke subject through promoting expression of parkin, a ubiquitin ligase playing a key role in the regulation of proteins and mitochondria quality control.

OBJECTIVE

To investigate the therapeutic effects of DHI on the histological, cellular, and functional recovery of Wistar rats after middle cerebral artery occlusion/reperfusion (MCAO/R).

METHODS

One hundred and twenty healthy male Wistar rats (250-300 g), were randomly assigned to six groups (twenty rats/group). Rats were subjected to 1 h MCAO/R and subsequently administered the intravenous doses of DHI (0.75, 1.5, and 3 mL/kg) to the respective groups (twice a day for 14 days). Unlike the other groups, the sham group received surgery without vessel occlusion. All the animals were tested for gait behavior using the CatWalk system. The body weight/survival rates were recorded daily for 14 days. The parkin protein expression of the brain tissue was quantified by immunohistochemistry analysis. Additionally, cultured cortical neurons were incubation with DHI or minocycline (MC) and then deprived of oxygen and glucose for 2 h (to resemble ischemic/reperfusion), followed by 4 h reoxygenation. Cellular and mitochondrial phenotypes were assayed by high content analysis.

RESULTS

Neurological integrity and paw parameters of the animals were altered in the model group but significantly ameliorated by DHI administration. Also, the infarct volume and survival rate were significantly improved in DHI groups. DHI enhanced the expression of parkin protein in the brain and improved the relative mitochondrial reductase activity of the cultured neurons.

CONCLUSIONS

The overall result shows that daily intervention with DHI provides neuroprotection and survival to improve gait motion in Wistar rats.