Cardiovascular fitness associated with cognitive performance in heart failure patients enrolled in cardiac rehabilitation

A systematic review about the importance of neuropsychological features in heart failure: is at heart the only failure?

Heart failure can lead to cognitive impairment that is estimated to be present in over a quarter of patients. It is important to intervene at a cognitive level to promote brain plasticity through cognitive training programs. Interventions transformed by technology offer the promise of improved cognitive health for heart failure patients. This review was conducted on studies evaluating the role of cognitive rehabilitation in patients with heart failure. We examined clinical trials involving patients with heart failure. Our search was performed on Pubmed, Web of Science and Cochrane library databases. Of the initial 256 studies, 10 studies met the inclusion criteria. Cognitive rehabilitation training has important implications for the treatment and prevention of cognitive decline in heart failure patients with significant recovery for delayed recall memory and a significant time effect for total recall memory and delayed, psychomotor speed and IADL performance. It is important to include the assessment of cognitive functioning in the routine clinical examinations of patients with heart failure, discover the relationship between cognitive function and heart failure, and target cognitive rehabilitation programs that promote brain plasticity.

Management of persistent sinus tachycardia during post-acute rehabilitation in a critical patient with COVID-19: a single-case study

Background

Sinus tachycardia is a common arrhythmia in patients with COVID-19, and may pose challenges during rehabilitation.

Case description

This is a case report of a 39-year-old critically ill patient with COVID-19 with no premorbid conditions, who presented with intensive care unit-acquired weakness and persistent sinus tachycardia after their stay in an intensive care unit. The sinus tachycardia and exertional symptoms contributed to a severely limited exercise capacity (assessed through the 6-Minute Walk Test and 2-Minute Step Test), which impaired the progress of inpatient rehabilitation. This was addressed through the use of bisoprolol for heart rate control and a rehabilitation programme based on cardiac rehabilitation principles.

Results

The patient's intensive care unit-acquired weakness improved with exercise-based rehabilitation, and the Functional Independence Measure motor subscore improved from 54/91 to 91/91 on discharge after 6 weeks of inpatient rehabilitation. After bisoprolol was started for sinus tachycardia, the patient's resting heart rate improved from 106 beats per minute to less than 90 beats per minute during this period of inpatient rehabilitation. During the same period, the patient exhibited concurrent improvement in exercise capacity on weekly 6-Minute Walk Test measurements. Improvements in the 2-Minute Step Test were also documented.

Conclusions

Patient assessment using submaximal exercise testing with serial 6-Minute Walk Tests and 2-Minute Step Tests, along with using beta-blockers and cardiac rehabilitation principles, can be useful in the post-acute rehabilitation of patients recovering from COVID-19 with persistent sinus tachycardia.

Poor Lower Extremity Functioning Is Associated with Modest Increased Incidence of Probable Dementia

Lower extremity functioning in older adults provides a measure of poor physical performance and can predict negative health outcomes. The consequences of reduced lower extremity functioning on cognitive decline, measured as time-varying variables, have not been well documented in previous studies. We aimed to evaluate whether lower extremity functioning is associated with an increased incidence rate of probable dementia among older adults using data from the National Health and Aging Trends Study (NHATS). Participants (n = 6457) were followed for 8 years to examine the relationship between lower extremity functioning, as measured by the Short Physical Performance Battery (SPPB), and incident probable dementia. Using weighted data, a multivariable Poisson regression with generalized estimating equations (GEE) was used to calculate incidence rate ratios (IRR), adjusting for covariates and clustering. Participants with low SPPB scores (0–5) had a 5% increase in incident probable dementia when compared with those who had good SPPB scores (10–12) in the adjusted model (IRR = 1.05; 95% CI = 1.04–1.07). Lower extremity functioning is associated with a modest increase in incident probable dementia. The SPPB score may be helpful in identifying subjects at risk of dementia. Efforts aimed at improving physical functioning may lead to better cognitive outcomes.

Multidomain Frailty in Heart Failure: Current Status and Future Perspectives

PURPOSE OF REVIEW

With a worldwide aging population, frailty and heart failure (HF) have become issues that need to be addressed urgently in cardiovascular clinical practice. In this review, we outline the clinical implications of frailty in HF patients and the potential therapeutic strategies to improve the clinical outcomes of frail patients with HF.

RECENT FINDINGS

Frailty has physical, psychological, and social domains, each of which is a prognostic determinant for patients with HF, and each domain overlaps with the other, although there are no standardized criteria for diagnosing frailty. Frailty can be targeted for treatment with various interventions, and recent studies have suggested that multidisciplinary intervention could be a promising option for frail patients with HF. However, currently, there is limited data, and further research is needed before its clinical implementation. Frailty and HF share a common background and are strongly associated with each other. More comprehensive assessment and therapeutic interventions for frailty need to be developed to further improve the prognosis and quality of life of frail patients with HF.

Effects of cardiac rehabilitation on cognitive impairments in patients with cardiovascular diseases: a systematic review

BACKGROUND

One of the most common problems associated with cardiovascular diseases (CVDs) is cognitive impairments (CIs) leading to reduced quality of life and treatment adherence in patients. The aim of this systematic review was to examine the effects of cardiac rehabilitation (CR) on cognitive function in CVD patients.

MATERIAL AND METHOD

PubMed, Scopus, Web of Science and Ovid MEDLINE databases were searched for identification the relevant studies without language restriction. We included the studies published from root to August 2019, evaluating the effects of CR on at least one type of cognitive functions through valid neuropsychological tests. Finally, nine studies with different study designs were entered in this systematic review. The full texts of these studies were critically appraised with various quality assessment tools.

RESULT

Patients were evaluated by different cognitive domains including global cognition, attention, executive function, memory and language prior to and following CR program among included studies. Most of the included studies reported significant cognitive improvement of the attention/executive function and memory domains. Two studies showed statistically significant improvement in global cognition using Modified Mini-Mental State (3MS) and Montreal Cognitive Assessment (MoCA) tools. Similar effects were not found in language domain.

CONCLUSION

It seems that cognitive impairments in CVD patients can be improved with CR program. Because this review is limited by low number of included studies, and there were various study designs without control groups, the results should be generalized cautiously. Further studies are recommended.

Two-Minute Step Test of Exercise Capacity: Systematic Review of Procedures, Performance, and Clinimetric Properties

BACKGROUND AND PURPOSE

The 2-minute step test (TMST) is one of many alternatives for measuring exercise capacity. First introduced in 1999 as part of the Senior Fitness Test, the TMST has the advantage of requiring limited space, only a few minutes' time, and no expensive equipment. These advantages notwithstanding, the test must be clinimetrically sound if it is to be recommended. We sought therefore to summarize the literature addressing TMST performance and measurement properties.

METHODS

Relevant literature was identified by searches of 3 electronic databases (PubMed, Scopus, and Cumulative Index of Nursing and Allied Health) and hand searches. Inclusion of an article required that it described use of the TMST of Rikli and Jones and that it focused on adults. Articles published in a language other than English were excluded. Studies were abstracted for information on participants, TMST description, and findings.

RESULTS AND DISCUSSION

Thirty articles were deemed appropriate based on inclusion and exclusion criteria. The participants in the studies included community-dwelling healthy older adults and adults with assorted pathologies. Studies described varied methods of conducting the TMST. Among tests in which steps for one side were counted over a full 2 minutes, the mean number of steps among populations ranged from 29.1 for patients with chronic stroke to 110.8 for older osteoporotic women. Numerous reviewed studies provide support for the validity of the TMST. Only one study addressed reliability and none focused on responsiveness. Normative data have been proffered.

CONCLUSIONS

The TMST has been widely used since first introduced, albeit not always as originally described. There is considerable evidence for the validity of the test, but its reliability and responsiveness are not yet firmly established.

The Effectiveness of Exercise on Cognitive Performance in Individuals with Known Vascular Disease: A Systematic Review

Patients with known vascular disease are at increased risk for cognitive impairments. Exercise has been shown to improve cognition in healthy elderly populations and those with mild cognitive impairments. We explored the literature to understand exercise as a modality to improve cognition in those with vascular disease, focusing on dose-responses. A systematic review was conducted through 2017 using Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Ovid Embase, and Ovid MEDLINE databases. Eligible studies examined effects of exercise on memory and cognition in cardiovascular (CVD) or cerebrovascular disease (CBVD). Data extracted included group characteristics, exercise dosage and outcomes measures employed. Twenty-two studies (12 CVD, 10 CBVD) met the inclusion criteria. Interventions included aerobic, resistance, or mixed training, with neuropsychological test batteries assessing cognition. In CVD populations, five studies demonstrated improved cardiovascular fitness and cognition with aerobic training, and another seven studies suggested a dose-response. In CBVD trials, four studies reported improved cognition, with no effects observed in the fifth study. Another study found enhanced cognition with resistance training and four demonstrated a positive association between functional capacity and cognition following combined aerobic and resistance training. Exercise is able to positively affect cognitive performance in those with known vascular disease. There is evidence to suggest a dose–response relationship. Further research is required to optimize prescription.

Gender Differences in the Impact of Cognitive Function on Health Literacy among Older Adults with Heart Failure

Heart failure (HF)-related cognitive decline is a common condition and may be associated with health literacy. However, gender differences in this context have not been explored fully. This secondary data analysis aimed to identify gender differences in the impact of cognitive function on health literacy among older patients with HF. A total of 135 patients (75 men and 60 women) with a mean age of 73.01 ± 6.45 years were recruited. Older women with HF had higher cognitive impairment (15%) and inadequate health literacy (56.7%) compared to men. Cognitive function was the strongest predictor of health literacy in men (β = 3.668, p < 0.001) and women (β = 2.926, p = 0.004). Notably elderly women are likely to face double the burden of the influence of cognitive function on health literacy in comparison with men. It is necessary to assess cognitive function and health literacy during HF illness trajectories on a regular basis. Healthcare professionals working with patients with HF should be aware of gender differences in cognitive function and health literacy and the importance of assessing these factors.

Cardiac rehabilitation and its effects on cognition in patients with coronary artery disease and heart failure

INTRODUCTION

Cardiac rehabilitation program is an evidence-based intervention and established model of exercise delivery following myocardial infarction and heart failure. Although it forms an important part of recovery and helps to prevent future events and complications, there has been little focus on its potential cognitive benefits. Areas covered: Coronary artery disease and heart failure are common heart problems associated with significant morbidity and mortality, and cognitive decline is commonly seen in affected individuals. Cognitive impairment may influence patient self-management by reducing medication adherence, rendering patients unable to make lifestyle modifications and causing missed healthcare visits. Cognitive assessment in cardiac rehabilitation as an outcome measure has the potential to improve clinical, functional and behavioral domains as well as help to reduce gaps in the quality of care in these patients. Expert commentary: Limited evidence at present has shown that cardiac rehabilitation and exercise has potential in preventing cognitive decline. Cardiac prehabilitation, a rehabilitation-like program delivered before cardiac surgery, may also play a role in preventing postoperative cognitive dysfunction, but needs future research studies to support it.

Gender Differences in Cognitive Test Performance in Adults With Heart Failure

BACKGROUND

Cognitive deficits are found in up to 73% of persons with heart failure (HF) and are associated with increased mortality and other poor clinical outcomes. It is known that women have better memory test performance than men do in healthy samples, but gender differences in cognitive performance in the context of HF are not well understood and may have important clinical implications.

OBJECTIVE

The objective of this study was to examine possible gender differences in cognitive function in a sample of individuals with HF (98.9% New York Heart Association class II and III).

METHODS

A total of 183 adults with HF (116 men and 67 women) completed a neuropsychological test battery as part of a larger project. Measures were chosen to assess functioning in attention/executive function and memory.

RESULTS

After controlling for demographic and medical factors, multivariate analysis of covariance revealed that men and women differed on memory test performance (λ = 0.90, F4, 169 = 4.76, P = .001). Post hoc comparisons revealed that women performed better on California Verbal Learning Test Learning, Short Recall, and Delayed Recall. No differences emerged on tests of attention/executive function (λ = 0.97, F5, 168 = 0.96, P = .44).

CONCLUSIONS

In this sample of persons with HF, men exhibited poorer performance on memory measures than women did. Future studies are needed to determine the underlying mechanisms for this pattern and its possible influence on daily function.

The effects of a 16-week aerobic exercise programme on cognitive function in people living with HIV

High levels of cardiovascular fitness and physical activity are associated with higher levels of cognitive function in people with HIV, thus, they may reduce the risk of developing HIV-associated neurocognitive disorder (HAND). This study aimed to investigate the effects of a 16-week aerobic exercise intervention on cognitive function in people with HIV. Eleven participants living with HIV were recruited into the study. Participants were randomised into either an exercise group (n = 5), that completed a 16-week aerobic exercise programme training, 3 times per week (2 supervised sessions and one unsupervised session) or a control group (n = 6) that received no intervention. Outcomes measured included cognitive function (Montreal cognitive assessment (MOCA) and the Trail making tests A and B), aerobic fitness (modified Bruce protocol), sleep quality (Pittsburgh sleep quality index; PSQI) and physical activity levels (seven-day accelerometry). At baseline, higher levels of moderate physical activity were positively correlated with higher MOCA scores and levels of aerobic fitness were negatively associated with Trail A scores (P = 0.04 and P = 0.001 respectively). However, exercise training did not induce any significant improvements in cognitive function or aerobic fitness. The overall mean adherence rate to the exercise programme was 60%. In conclusion, in the present study a 16-week aerobic exercise intervention did not affect the cognitive function of participants with HIV. It is likely that longer intervention periods and/or higher adherence rates to exercise might be needed for an aerobic exercise programme to be effective in improving cognitive function in a cohort with no baseline cognitive impairments.

Reduced Gray Matter Volume Is Associated With Poorer Instrumental Activities of Daily Living Performance in Heart Failure

BACKGROUND

Heart failure patients require assistance with instrumental activities of daily living in part because of the high rates of cognitive impairment in this population. Structural brain insult (eg, reduced gray matter volume) is theorized to underlie cognitive dysfunction in heart failure, although no study has examined the association among gray matter, cognition, and instrumental activities of daily living in heart failure.

OBJECTIVES

The aim of this study was to investigate the associations among gray matter volume, cognitive function, and functional ability in heart failure.

METHODS

A total of 81 heart failure patients completed a cognitive test battery and the Lawton-Brody self-report questionnaire to assess instrumental activities of daily living. Participants underwent magnetic resonance imaging to quantify total gray matter and subcortical gray matter volume.

RESULTS

Impairments in instrumental activities of daily living were common in this sample of HF patients. Regression analyses controlling for demographic and medical confounders showed that smaller total gray matter volume predicted decreased scores on the instrumental activities of daily living composite, with specific associations noted for medication management and independence in driving. Interaction analyses showed that reduced total gray matter volume interacted with worse attention/executive function and memory to negatively impact instrumental activities of daily living.

CONCLUSIONS

Smaller gray matter volume is associated with greater impairment in instrumental activities of daily living in persons with heart failure, possibly via cognitive dysfunction. Prospective studies are needed to clarify the utility of clinical correlates of gray matter volume (eg, cognitive dysfunction) in identifying heart failure patients at risk for functional decline and determine whether interventions that target improved brain and cognitive function can preserve functional independence in this high-risk population.

Could the two-minute step test be an alternative to the six-minute walk test for patients with systolic heart failure?

BACKGROUND

The consequence of exercise intolerance for patients with heart failure is the difficulty climbing stairs. The two-minute step test is a test that reflects the activity of climbing stairs.

DESIGN

The aim of the study design is to evaluate the applicability of the two-minute step test in an assessment of exercise tolerance in patients with heart failure and the association between the six-minute walk test and the two-minute step test.

METHODS

Participants in this study were 168 men with systolic heart failure (New York Heart Association (NYHA) class I-IV). In the study we used the two-minute step test, the six-minute walk test, the cardiopulmonary exercise test and isometric dynamometer armchair.

RESULTS

Patients who performed more steps during the two-minute step test covered a longer distance during the six-minute walk test (r = 0.45). The quadriceps strength was correlated with the two-minute step test and the six-minute walk test (r = 0.61 and r = 0.48). The greater number of steps performed during the two-minute step test was associated with higher values of peak oxygen consumption (r = 0.33), ventilatory response to exercise slope (r = -0.17) and longer time of exercise during the cardiopulmonary exercise test (r = 0.34). Fatigue and leg fatigue were greater after the two-minute step test than the six-minute walk test whereas dyspnoea and blood pressure responses were similar.

CONCLUSION

The two-minute step test is well tolerated by patients with heart failure and may thus be considered as an alternative for the six-minute walk test.

Reduced Physical Fitness in Patients With Heart Failure as a Possible Risk Factor for Impaired Driving Performance

OBJECTIVE

Reduced physical fitness secondary to heart failure (HF) may contribute to poor driving; reduced physical fitness is a known correlate of cognitive impairment and has been associated with decreased independence in driving. No study has examined the associations among physical fitness, cognition, and driving performance in people with HF.

METHOD

Eighteen people with HF completed a physical fitness assessment, a cognitive test battery, and a validated driving simulator scenario.

RESULTS

Partial correlations showed that poorer physical fitness was correlated with more collisions and stop signs missed and lower scores on a composite score of attention, executive function, and psychomotor speed. Cognitive dysfunction predicted reduced driving simulation performance.

CONCLUSION

Reduced physical fitness in participants with HF was associated with worse simulated driving, possibly because of cognitive dysfunction. Larger studies using on-road testing are needed to confirm our findings and identify clinical interventions to maximize safe driving.

Possible neurocognitive benefits of exercise in persons with heart failure

More than 6 million Americans have heart failure (HF) and more than 500,000 are diagnosed each year. In addition to its many adverse medical consequences, HF is also a significant risk factor for neurological disorders like Alzheimer's disease and associated with cognitive impairment long prior to the onset of these conditions. Converging bodies of literature suggest cognitive dysfunction in HF may be at least partially modifiable. One key mechanism for cognitive improvement is improved cerebral blood flow, which may be possible with exercise in patients with HF. This brief review provides a model for the likely neurocognitive benefits of exercise in HF and encourages further work in this area.

Cognitive function in ambulatory patients with systolic heart failure: insights from the warfarin versus aspirin in reduced cardiac ejection fraction (WARCEF) trial

We sought to determine whether cognitive function in stable outpatients with heart failure (HF) is affected by HF severity. A retrospective, cross-sectional analysis was performed using data from 2, 043 outpatients with systolic HF and without prior stroke enrolled in the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) Trial. Multivariable regression analysis was used to assess the relationship between cognitive function measured using the Mini-Mental Status Exam (MMSE) and markers of HF severity (left ventricular ejection fraction [LVEF], New York Heart Association [NYHA] functional class, and 6-minute walk distance). The mean (SD) for the MMSE was 28.6 (2.0), with 64 (3.1%) of the 2,043 patients meeting the cut-off of MMSE <24 that indicates need for further evaluation of cognitive impairment. After adjustment for demographic and clinical covariates, 6-minute walk distance (β-coefficient 0.002, p<0.0001), but not LVEF or NYHA functional class, was independently associated with the MMSE as a continuous measure. Age, education, smoking status, body mass index, and hemoglobin level were also independently associated with the MMSE. In conclusion, six-minute walk distance, but not LVEF or NYHA functional class, was an important predictor of cognitive function in ambulatory patients with systolic heart failure.

Cardiac rehabilitation is associated with lasting improvements in cognitive function in older adults with heart failure

OBJECTIVE

Heart failure (HF) is a known risk factor for cognitive impairment. Cardiac rehabilitation (CR) may attenuate poor neurocognitive outcomes in HF via improved physical fitness--a significant promoter of cognitive function. However, no study has examined the possible acute and lasting benefits of CR on cognitive function in persons with HF.

METHODS AND RESULTS

Fifty-two patients with HF completed a 12-week Phase II CR program. All participants were administered neuropsychological testing and completed a brief physical fitness assessment at baseline, completion of CR (i.e. 12 weeks), and 12-month follow-up. Repeated measures analyses showed a significant time effect for both attention/executive function and memory (P < 0.05). Attention/executive function performance increased from baseline to 12 weeks and these gains remained up to 12 months; memory was unchanged from baseline to 12 weeks, but then improved between the 12-week and 12-month time points. Physical fitness improved from baseline to 12 weeks and these benefits were maintained 12 months later. Changes in physical fitness and cognitive function over time did not reach a statistically significant association, though poorer physical fitness was associated with decreased cognitive performance at the baseline and 12-month time points.

CONCLUSIONS

CR is associated with both acute and lasting cognitive benefits in patients with HF. Prospective studies with extended follow-ups are needed to clarify the mechanisms that underpin cognitive improvements following CR (e.g., improved cerebral perfusion) and whether CR can ultimately reduce risk for cognitive decline and conditions like Alzheimer's disease in HF.

Better adherence to treatment recommendations in heart failure predicts improved cognitive function at a one-year follow-up

INTRODUCTION

Treatment nonadherence is common in heart failure (HF) and is associated with poor health outcomes in this population. Recent cross-sectional work in heart failure and past work in other medical populations suggest that cognitive function is a key determinant of a patient's ability to adhere to treatment recommendations. However, it is also possible that treatment adherence is an important modifier and predictor of cognitive function, though no study has examined this possibility, and we sought to do so in a sample of heart failure patients.

METHOD

A total of 115 patients with heart failure self-reported adherence to treatment recommendations. The Modified Mini Mental State Examination (3MS), Trail Making Test Parts A and B, and the California Verbal Learning Test-II (CVLT-II) assessed cognitive function. These procedures were performed at baseline and a 12-month follow-up.

RESULTS

Global cognition and memory abilities improved over the 12-month period. Regression analyses controlling for baseline and medical and demographic factors showed that better baseline treatment adherence predicted improved 12-month performances on the 3MS and CVLT-II. Adherence to medication and diet regimens and smoking abstinence emerged as the most important contributors.

CONCLUSIONS

Better treatment adherence predicted improved cognition one year later in HF. Prospective studies that utilize objective assessments of treatment adherence are needed to confirm our findings and examine whether improved treatment adherence preserves cognitive function in heart failure.

COPD is associated with cognitive dysfunction and poor physical fitness in heart failure

OBJECTIVE

To examine the associations among chronic obstructive pulmonary disease (COPD), cognitive function, and physical fitness in heart failure (HF).

BACKGROUND

Cognitive impairment in HF in part stems from medical comorbidities and poor physical fitness. COPD, a frequent co-existing condition in HF, is a risk factor for cognitive impairment and a known cause of poor physical fitness. Yet, the interplay among COPD, cognition, and physical fitness has never been examined in HF.

METHODS

191 HF patients completed a cognitive test battery and brief physical fitness assessment. Diagnostic history of COPD was ascertained via medical chart review.

RESULTS

Regression analyses showed HF patients with COPD exhibited worse attention/executive function and poorer fitness relative to their non-COPD counterparts. Worse fitness correlated with cognitive dysfunction.

CONCLUSIONS

COPD is associated with reduced cognition and worse fitness in HF. Longitudinal work that employs objective assessments of COPD is needed to determine directionality and clarify mechanisms.

Relationship between physical performance and cognitive performance measures among community-dwelling older adults

Purpose

Cognitive impairment is correlated with physical function. However, the results in the literature are inconsistent with cognitive and physical performance measures. Thus, the aim of this study was to determine the association between cognitive performance and physical function among older adults.

Methods

A total of 164 older adults aged ≥60 years and residing in low-cost housing areas in Kuala Lumpur, Malaysia participated in this study. Cognitive performance was measured using the Mini Mental State Examination, clock drawing test, Rey auditory verbal learning test, digit symbol test, digit span test, matrix reasoning test, and block design test. Physical performance measures were assessed using the ten step test for agility, short physical performance battery test for an overall physical function, static balance test using a Pro.Balance board, and dynamic balance using the functional reach test.

Results

There was a negative and significant correlation between agility and the digit symbol test (r=−0.355), clock drawing test (r=−0.441), matrix reasoning test (r=−0.315), and block design test (r=−0.045). A significant positive correlation was found between dynamic balance, digit symbol test (r=0.301), and matrix reasoning test (r=0.251). The agility test appeared as a significant (R²=0.183, R²=0.407, R²=0.299, P<0.05) predictor of some cognitive performance measures, including the digit span test, clock drawing test, and Mini Mental State Examination.

Conclusion

These results suggest that a decline in most cognitive performance measures can be predicted by poor execution of a more demanding physical performance measure such as the ten step test for agility. It is imperative to use a more complex and cognitively demanding physical performance measure to identify the presence of an overall cognitive impairment among community-dwelling older adults. It may also be beneficial to promote more complex and cognitively challenging exercises and activities among older adults for optimal physical and cognitive function.

The Effects of Aerobic Exercise on Cognitive and Neural Decline in Aging and Cardiovascular Disease

Aging is characterized by a decline in cognitive functions, particularly in the domains of executive function, processing speed and episodic memory. These age-related declines are exacerbated by cardiovascular disease (CVD) and cardiovascular risk factors (hypertension, diabetes, obesity, elevated total cholesterol). Structural and functional alterations in brain regions, including the fronto-parietal and medial temporal lobes, have been linked to age- and CVD-related cognitive decline. Multiple recent studies indicate that aerobic exercise programs may slow the progression of age-related neural changes and reduce the risk for mild cognitive impairment as well as dementia. We review age- and CVD-related decline in cognition and the underlying changes in brain morphology and function, and then clarify the impact of aerobic exercise on moderating these patterns.

Dairy intake is associated with memory and pulsatility index in heart failure

PURPOSE/AIM

Past work shows an inconsistent relationship between dairy intake and cognition in healthy older adults. A cross-sectional design was conducted to examine dairy consumption, cognitive dysfunction, and cerebral blood flow in a sample of older adults with heart failure (HF) to clarify their association in this population at high risk for adverse neurocognitive outcomes.

MATERIALS AND METHODS

A total of 86 older adults with HF (70.39 ± 9.51 years; 33.1% female) underwent neuropsychological testing, transcranial Doppler (TCD) sonography to quantify cerebral blood flow. Dairy intake was quantified using a brief self-report questionnaire.

RESULTS

Partial correlations between the dairy consumption questionnaire and neuropsychological tests were conducted adjusting for HF severity, age, and sex. Contrary to expectations, results showed greater dairy intake was associated with poorer memory (r = -0.21, p = 0.01) and higher pulsatility index in the medial cerebral artery (r = -0.17, p = 0.05).

CONCLUSION

Results suggest that greater dairy intake was associated with poorer memory performance in older adults with HF. Several possible explanations for these findings exist, including the contribution of high-fat dairy to underlying physiological processes that promote vascular cognitive impairment. Prospective studies employing objective measures specific to high and low fat dairy are needed to clarify this possibility.

Obesity and cognitive dysfunction in heart failure: the role of hypertension, type 2 diabetes, and physical fitness

BACKGROUND

Cognitive impairment is common in heart failure. Obesity is a known risk factor for cognitive dysfunction in heart failure, though the mechanisms remain unclear. Obesity increases risk for conditions like hypertension and type 2 diabetes mellitus (T2DM) as well as poor fitness levels, and this may serve as one possible pathway accounting for association between obesity and cognitive dysfunction.

AIMS

We used structural equation modeling to test whether the combination of hypertension, T2DM, and reduced fitness mediate the association between obesity and cognitive dysfunction.

METHODS

Two hundred heart failure patients completed neuropsychological testing and a physical fitness assessment. Hypertension and T2DM were ascertained via self-report and medical records. Body mass index (BMI) was calculated.

RESULTS

Forty-three percent of the sample was obese. Hypertension (70%) and T2DM (36%) were common, and fitness levels were reduced. The structural equation model with these factors as mediators between BMI and cognitive function demonstrated excellent fit (comparative fit index = 0.98; root mean-square error of approximations = 0.03). Higher BMI correlated with hypertension, T2DM, and poorer fitness. Each of these factors predicted worse cognition. Models that isolated medical comorbidities and physical fitness as the mediator were weaker than the full model.

CONCLUSIONS

Increased risk for medical comorbidities and reduced fitness levels helped to explain the negative effects of obesity on cognitive dysfunction in heart failure. Prospective studies should confirm this pattern and examine how weight loss benefits cognitive function in heart failure.

Reduced cerebral perfusion predicts greater depressive symptoms and cognitive dysfunction at a 1-year follow-up in patients with heart failure

OBJECTIVE

Cerebral hypoperfusion is common in heart failure (HF) and believed to underlie poor neurocognitive outcomes in this population. Up to 42% of HF patients also exhibit depressive symptomatology that may stem from reduced cerebral blood flow. However, no study has examined this possibility or whether reduced brain perfusion increases risk for future cognitive dysfunction in older adults with HF.

METHODS

One hundred HF patients underwent transcranial Doppler ultrasonagraphy to quantify global cerebral blood flow velocity (CBF-V) and were administered a cognitive test battery to assess global cognition, attention/executive function, and memory abilities. All participants then completed the Beck Depression Inventory-II to assess depressive symptomatology. These procedures were performed at baseline and at 12-month follow-up.

RESULTS

Repeated measures revealed that CBF-V declined over the 12-month period. Regression analyses showed that reduced baseline CBF-V predicted worse performances in attention/executive function (p < 0.05 for all) and a trend for memory (p = 0.09) in addition to greater depressive symptomatology (p < 0.05) at the 12-month follow-up, even after controlling for baseline factors and medical and demographic variables.

CONCLUSIONS

Cerebral perfusion declined over time and was associated with poorer cognitive function and greater depressive symptoms at a 1-year follow-up in HF. Prospective studies with long-term follow-ups that employ neuroimaging are needed to examine whether cognitive dysfunction and depression in HF stem from the adverse effects of cerebral hypoperfusion on the cerebral structure.

Cognitive dysfunction mediates the effects of poor physical fitness on decreased functional independence in heart failure

AIM

Heart failure (HF) patients require assistance with activities of daily living (ADL). Poor physical fitness has recently been identified as a contributor to the high rates of disability in HF, though the mechanisms for such effects are unclear. Although not previously examined, decreased fitness might adversely impact ADL in HF through its known association with cognitive impairment, a key correlate of self-care abilities in this population. We sought to test this possibility using a model-based approach.

METHODS

A total of 197 patients with HF completed a physical fitness test and a neuropsychological test battery. A total ADL composite was derived from the Lawton Brody scale. Structural equation modeling tested whether cognitive function mediated the association between physical fitness and total ADL.

RESULTS

Fitness was reduced, and cognitive dysfunction and impaired ADL were prevalent. The initially significant association between fitness and total ADL was attenuated when cognitive function was introduced as a mediator. This model showed good fit (comparative fit index=0.91: root mean-square error of approximations=0.077) with a significant indirect pathway between physical fitness and total ADL through cognitive function: Decreased physical fitness was associated with cognitive dysfunction (β=0.35), which predicted greater assistance with ADL (β=0.22).

CONCLUSIONS

Poor physical fitness might lead to decreased functional independence in HF through its negative effects on cognitive function. Prospective studies are required to confirm our findings, identify other mechanisms by which poor fitness impacts ADL, and examine whether exercise interventions can improve cognition and help preserve ADL independence in HF.

Decreased physical activity predicts cognitive dysfunction and reduced cerebral blood flow in heart failure

OBJECTIVE

Cognitive impairment in heart failure (HF) is believed to result from brain hypoperfusion subsequent to cardiac dysfunction. Physical inactivity is prevalent in HF and correlated with reduced cardiac and cognitive function. Yet, no longitudinal studies have examined the neurocognitive effects of physical inactivity in HF. The current study examined whether reduced physical activity increases risk for cognitive impairment and brain hypoperfusion over time in HF.

METHODS

At baseline and 12 months later, 65 HF patients underwent neuropsychological testing, transcranial Doppler ultrasonography, and were asked to wear an accelerometer for seven days.

RESULTS

Lower baseline step count and less time spent in moderate free-living activity best predicted worse attention/executive function and decreased cerebral perfusion at the 12-month follow-up. Decreased baseline cerebral perfusion also emerged as a strong predictor of poorer 12-month attention/executive function.

CONCLUSIONS

Lower physical activity predicted worse cognition and cerebral perfusion 12 months later in HF. Physical inactivity in HF may contribute to cognitive impairment and exacerbate risk for conditions such as Alzheimer's disease. Larger studies are needed to elucidate the mechanisms by which physical inactivity leads to cognitive dysfunction in HF, including clarification of the role of cerebral hypoperfusion.

Reduced cerebral blood flow and white matter hyperintensities predict poor sleep in heart failure

BACKGROUND

Poor sleep is common in heart failure (HF), though mechanisms of sleep difficulties are not well understood. Adverse brain changes among regions important for sleep have been demonstrated in patients with HF. Cerebral hypoperfusion, a correlate of sleep quality, is also prevalent in HF and a likely contributor to white matter hyperintensities (WMH). However, no study to date has examined the effects of cerebral blood flow, WMH, and brain volume on sleep quality in HF.

METHODS

Fifty-three HF patients completed the Pittsburgh Sleep Quality Index and underwent brain magnetic resonance imaging to quantify brain and WMH volume. Transcranial Doppler ultrasonography assessed cerebral blood flow velocity of the middle cerebral artery (CBF-V of the MCA).

RESULTS

75.5% of HF patients reported impaired sleep. Regression analyses adjusting for medical and demographic factors showed decreased CBF-V of the MCA and greater WMH volume were associated with poor sleep quality. No such pattern emerged on total brain or regional volume indices.

CONCLUSIONS

Decreased cerebral perfusion and greater WMH may contribute to sleep difficulties in HF. Future studies are needed to confirm these findings and clarify the effects of cerebral blood flow and WMH on sleep in healthy and patient samples.

Cognitive performance in older adults with stable heart failure: longitudinal evidence for stability and improvement

Cognitive impairment is prevalent in heart failure (HF), though substantial variability in the pattern of cognitive impairment is found across studies. To clarify the nature of cognitive impairment in HF, we examined longitudinal trajectories across multiple domains of cognition in HF patients using latent growth class modeling. 115 HF patients completed a neuropsychological battery at baseline, 3-months and 12-months. Participants also completed the Beck Depression Inventory-II (BDI-II). Latent class growth analyses revealed a three-class model for attention/executive function, four-class model for memory, and a three-class model for language. The slope for attention/executive function and language remained stable, while improvements were noted in memory performance. Education and BDI-II significantly predicted the intercept for attention/executive function and language abilities. The BDI-II also predicted baseline memory. The current findings suggest that multiple performance-based classes of neuropsychological test performance exist within cognitive domains, though case-controlled prospective studies with extended follow-ups are needed to fully elucidate changes and predictors of cognitive function in HF.