John Gunstad

Cognitive impairment is independently associated with reduced instrumental activities of daily living in persons with heart failure

Background:Heart failure (HF) is a disabling disease that often affects instrumental activities of daily living (instrumental ADLs). Despite high rates of disability in this population, little is known about the effects of cognitive impairment on instrumental ADLs in this population. Objective:The current study examined whether cognitive functioning predicts instrumental ADL performance in persons with HF. Methods:Persons with HF (N = 122; 68.49 [SD, 9.43] years; 35.2% female) completed neuropsychological testing, fitness assessment, and self-reported instrumental and basic ADL function as part of a larger protocol. Neuropsychological tests included the Mini-Mental State Examination and Trail Making Tests A and B. The 2-minute step test estimated fitness. Instrumental and basic ADL function was based on self-report on the Lawton-Brody Activities of Daily Living Scale. Hierarchical regression analyses were used to determine the independent contribution of cognitive function to ADLs in HF. Results:Heart failure patients reported high rates of impairments in instrumental ADLs, but indicated requiring little or no assistance with basic ADLs. Cognitive function showed incremental predictive validity for driving (R2 change = .07, P = .03) and medication management (R2 change = .14, P < .001). In each case, poorer neuropsychological test performance was associated with poorer instrumental ADL function. Conclusion:In persons with HF, cognitive performance is an independent predictor of independence in driving and medication management. Strategies to maintain or improve cognitive functioning in HF may help patients remain functionally independent in their daily living.

Cerebral Perfusion is Associated With White Matter Hyperintensities in Older Adults With Heart Failure

Cognitive impairment is common in heart failure (HF) and believed to be the result of cerebral hypoperfusion and subsequent brain changes including white matter hyperintensities (WMHs). The current study examined the association between cerebral blood flow and WMHs in patients with HF and the relationship between WMHs and cognitive impairment. Sixty-nine patients with HF completed the Mini-Mental State Examination (MMSE) and underwent echocardiography, transcranial Doppler sonography for cerebral blood flow velocity of the middle cerebral artery, and brain magnetic resonance imaging. Multivariable hierarchical regression analyses controlling for medical and demographic characteristics as well as intracranial volume showed reduced cerebral blood flow velocity of the middle cerebral artery was associated with greater WMHs (β=-0.34, P=.02). Follow-up regression analyses adjusting for the same medical and demographic factors in addition to cerebral perfusion also revealed marginal significance between increased WMHs and poorer performance on the MMSE (β=-0.26, P=.05). This study suggests that reduced cerebral perfusion is associated with greater WMHs in older adults with HF. These findings support the widely proposed mechanism of cognitive impairment in HF patients and prospective studies are needed to confirm these results.

Cognitive function and treatment adherence in older adults with heart failure.

Objective Treatment recommendation and guidelines for patients with heart failure (HF) can be complex, and past work has shown that patients with HF demonstrate low rates of adherence to recommended health behaviors. Although previous work has identified several medical, demographic, and psychosocial predictors of the capacity to adhere to treatment recommendations of persons with HF, little is known about the contribution of cognitive impairment to reported treatment adherence in this population. Methods A total of 149 persons with HF (mean [standard deviation] = 68.08 [10.74] years) completed a brief fitness assessment and neuropsychological testing. Treatment adherence was assessed using the Heart Failure Compliance Questionnaire, a brief measure that asks participants to report their adherence to a variety of recommended health behaviors (i.e., medication management, diet, and exercise, among others). Results The percentage of participants who reported poor overall adherence was 16.1%, with particularly high rates of nonadherence to dietary and exercise recommendations. Hierarchical regression analyses adjusting for possible confounds revealed that reduced performance on attention (&bgr; = .26, p = .01), executive function (&bgr; = .18, p = .04), and language (&bgr; = .22, p = .01) was associated with poorer overall adherence. Follow-up analyses showed that these cognitive domains were associated with behaviors such as keeping doctor appointments, medication management, and dietary recommendations (p < .05 for all). Conclusions The current findings demonstrate that cognitive function is an independent contributor to adherence in older adults with HF. Prospective studies that objectively measure treatment adherence are needed to clarify these findings and identify possible strategies to improve outcomes in this population. Trial Registration: clinicaltrials.gov Identifier: NCT00871897.

Improvements in Cognitive Function Following Cardiac Rehabilitation for Older Adults With Cardiovascular Disease

ABSTRACT Cognitive impairment is common in persons with cardiovascular disease (CVD). Cardiac rehabilitation (CR) improves many aspects of CVD linked to cognitive impairment. The current study explored whether CR may improve cognitive function. Potential mechanisms for cognitive changes were also examined through exploratory analyses, including changes in cardiovascular fitness and cerebral blood flow. Fifty-one older adults with CVD underwent neuropsychological assessment at baseline and discharge from a 12-week CR program. Cardiovascular fitness (i.e., metabolic equivalents [METs]) was estimated from a symptom-limited volitional stress test. Transcranial doppler quantified mean cerebral blood flow velocity and pulsatility indexes for the middle cerebral artery and anterior cerebral artery (ACA). Repeated measures ANOVA showed improvements in global cognition, attention-executive-psychomotor function, and memory. Exploratory analyses revealed improvement in METs and changes in ACA flow velocity, but only improvement in METs was related to improved verbal recall. CVD patients exhibited improvements in multiple cognitive domains following a 12-week CR program, suggesting that cognitive impairment is modifiable in this population. Although other studies are needed to elucidate underlying mechanisms, exploratory analyses suggest that cognitive improvements may be better explained by physiological processes other than improved cardiovascular fitness and cerebral blood flow.

Depression is associated with reduced physical activity in persons with heart failure.

OBJECTIVEnReduced physical activity is common in persons with heart failure (HF). However, studies of correlates and modifiers of physical activity in this population rarely employ objective measures. Motivational and mood related factors that may exacerbate inactivity in HF patients are also rarely investigated. In this study, we examined the relationship between physical activity as assessed by accelerometry, and depression in older adults with HF.nnnMETHODSnAt baseline, older adults with HF (N = 96; 69.81 ± 8.79) wore an accelerometer for seven days, and completed a brief fitness assessment, neuropsychological testing, and psychosocial measures including the Beck Depression Inventory-II (BDI-II). Medical and demographic history was obtained through record review and self-report.nnnRESULTSnAccelerometer measures showed that HF patients averaged 587 minutes of sedentary time and just 0.31 minutes of vigorous activity per day. Lower daily step count was associated with poorer quality of life and reduced cognitive function. A multiple linear regression adjusting for important demographic and medical variables found that greater number of depressive symptoms on the BDI-II independently predicted lower physical activity levels.nnnCONCLUSIONnConsistent with past work, the current study found that low physical activity is common in older adults with HF. Depression is an independent predictor of physical activity in older adults with HF and reduced physical activity is associated with numerous adverse psychosocial outcomes. Future studies need to determine whether treatment of depression can boost physical activity and thus improve health outcomes in this population.

Depression is associated with cognitive dysfunction in older adults with heart failure.

Persons with heart failure (HF) frequently exhibit cognitive impairment with deficits in attention and memory. Depression is common in HF though its possible contribution to cognitive impairment is unknown. Cognitive dysfunction and depression may share common mechanisms in HF, as both are associated with similar abnormalities on neuroimaging. A total of 116 participants with HF (68.53 ± 9.30 years) completed a neuropsychological battery and self-report measures of depression. Regression models showed depression incrementally and independently predicted test performance in all cognitive domains. Follow-up partial correlations revealed that greater depressive symptoms were associated with poorer performance on tests of attention, executive function, psychomotor speed, and language. These results indicate that depressive symptoms are associated with poorer cognitive performance in HF though further work is needed to clarify mechanisms for this association and possible cognitive benefits of treating depression in persons with HF.

Sleep apnea and cognitive function in heart failure

Background. Prior research indicates that heart failure (HF) patients exhibit significant cognitive deficits on neuropsychological testing. Sleep apnea is associated with both HF and reduced cognitive function, but the combined impact of these conditions on cognitive function is unknown. Methods. In the current study, 172 older adults with a dual diagnosis of HF and sleep apnea or HF alone completed a battery of cognitive tests measuring attention, executive functioning, and memory. Results. Relative to patients with HF alone, persons with both HF and sleep apnea performed worse on measures of attention after adjusting for demographic and medical variables. Conclusions. The current findings suggest that HF patients with comorbid sleep apnea may be at greater risk for cognitive impairment relative to HF patient without such history. Further work is needed to clarify mechanisms for these findings and to determine whether the interactive effects on cognitive function lead to poorer patient outcomes.

Executive Dysfunction is Independently Associated with Reduced Functional Independence in Heart Failure

AIMS AND OBJECTIVESnTo examine the independent association between executive function with instrumental activities of daily living and health behaviours in older adults with heart failure.nnnBACKGROUNDnExecutive function is an important contributor to functional independence as it consists of cognitive processes needed for decision-making, planning, organising and behavioural monitoring. Impairment in this domain is common in heart failure patients and associated with reduced performance of instrumental activities of daily living in many medical and neurological populations. However, the contribution of executive functions to functional independence and healthy lifestyle choices in heart failure patients has not been fully examined.nnnDESIGNnCross-sectional analyses.nnnMETHODSnOne hundred and seventy-five heart failure patients completed a neuropsychological battery and echocardiogram. Participants also completed the Lawton-Brody Instrumental Activities of Daily Living Scale and reported current cigarette use.nnnRESULTSnHierarchical regressions revealed that reduced executive function was independently associated with worse instrumental activity of daily living performance with a specific association for decreased ability to manage medications. Partial correlations showed that executive dysfunction was associated with current cigarette use.nnnCONCLUSIONSnOur findings suggest that executive dysfunction is associated with poorer functional independence and contributes to unhealthy behaviours in heart failure. Future studies should examine whether heart failure patients benefit from formal organisation schema (i.e. pill organisers) to maintain independence.nnnRELEVANCE TO CLINICAL PRACTICEnScreening of executive function in heart failure patients may provide key insight into their ability to perform daily tasks, including the management of treatment recommendations.

The Interactive Effects of Cerebral Perfusion and Depression on Cognitive Function in Older Adults with Heart Failure

Objective Depression is common among persons with heart failure (HF) and has been linked to cognitive impairment in this population. The mechanisms of this relationship are unclear, and the current study examined whether cerebral perfusion moderates the association between depressive symptoms and cognitive impairment in patients with HF. Methods Persons with HF (n = 89; mean [standard deviation] age = 67.61 [11.78] years) completed neuropsychological testing and impedance cardiography. Depressive symptoms were assessed using the Beck Depression Inventory II, and transcranial Doppler was used to quantify cerebral perfusion. Results Depression was associated with reduced performance on tasks assessing attention/executive function (r = −0.28), language (r = −0.0.30), and motor function (r = −0.28) in unadjusted models (p values <.05). Global cerebral blood flow was correlated with memory performance (r = 0.22, p = .040) but not with other tasks. A moderation analysis was performed using hierarchical regression models for attention/executive function, memory, language, and motor function. For each model, medical and demographic characteristics were entered into the initial blocks, and the final block consisted of an interaction term between global cerebral blood flow velocity and the Beck Depression Inventory II. The interaction between greater depressive symptoms and decreased global cerebral blood flow velocity was associated with greater deficits in attention/executive function (&bgr; = .32, &Dgr;R2 = 0.08, p = .003). Conclusions Depressive symptoms and cerebral hypoperfusion interact to adversely affect cognitive performance in older adults with HF. Longitudinal studies are needed to clarify this relationship and elucidate subsequent neuropathology.

The Additive Effects of Type-2 Diabetes on Cognitive Function in Older Adults with Heart Failure

Background. Medical comorbidity has been theorized to contribute to cognitive impairment in heart failure (HF) patients. Specifically, type-2 diabetes mellitus (T2DM), a common coexisting condition among HF patients, may be an independent predictor of cognitive impairment. Nonetheless, the relationships between T2DM and other risk factors for cognitive impairment among persons with HF are unclear. Methods. Persons with HF (N = 169, 34.3% women, age 68.57 ± 10.28 years) completed neuropsychological testing within a framework of an ongoing study. History of T2DM, along with other medical characteristics, was ascertained through a review of participants medical charts and self-report. Results. Many participants (34.9%) had a comorbid T2DM diagnosis. After adjustment for demographic and medical characteristics, HF patients with T2DM evidenced significantly greater impairments across multiple cognitive domains than HF patients without T2DM: λ = .92, F(5, 156) = 2.82, P = .018. Post hoc tests revealed significant associations between T2DM and attention (P = .003), executive function (P = .032), and motor functioning (P = .008). Conclusion. The findings suggest additive contributions of T2DM and HF to impairments in attention, executive function, and motor function. Future work is needed to elucidate the mechanisms by which T2DM exacerbates cognitive impairment in HF.