Sleep disordered breathing, daytime symptoms, and functional performance in stable heart failure

Unveiling stress markers: A systematic review investigating psychological stress biomarkers

Psychological stress is a ubiquitous facet of modern life, impacting individuals across diverse contexts and demographics. Understanding its physiological manifestations through biomarkers has gained substantial attention within the scientific community. A comprehensive search was conducted across multiple databases for peer-reviewed articles published within the past decade. Preliminary findings reveal many biomarkers associated with psychological stress across different biological systems, including the hypothalamic-pituitary-adrenal axis, immune system, cardiovascular system, and central nervous system. This systematic review explores psychological, physiological, and biochemical biomarkers associated with stress. Analyzing recent literature, it synthesizes findings across these three categories, elucidating their respective roles in stress response mechanisms. Psychological markers involve subjective assessments like self-reported stress levels, perceived stress scales, or psychometric evaluations measuring anxiety, depression, or coping mechanisms. Physiological markers include heart rate variability, blood pressure, and immune system responses such as cytokine levels or inflammatory markers. Biochemical markers involve hormones or chemicals linked to stress. It includes cortisol, catecholamines, copeptin, salivary amylase, IL-6, and C-reactive protein.

Correlates of cognition among people with chronic heart failure and insomnia

PURPOSE

This study aimed to describe cognitive characteristics and their associations with demographic and clinical factors among adults with chronic heart failure (HF) and insomnia.

METHODS

We performed a cross-sectional analysis of baseline data from the HeartSleep Study (NCT#02,660,385), a randomized controlled trial designed to evaluate the effects of cognitive-behavioral therapy for insomnia. Demographic characteristics and health history were obtained. We measured sleep characteristics with the Insomnia Severity Index, the PROMIS Sleep Disturbance Questionnaire, and wrist actigraphy. Sleepiness, stress, and quality of life were measured with validated questionnaires. Measures of cognition included frequency of lapses on the psychomotor vigilance test and the PROMIS cognitive abilities scale where ≥ 3 lapses and a score of ≤ 50, respectively, suggested impairment. These variables were combined into a composite score for multivariable analyses.

RESULTS

Of a sample that included 187 participants (58% male; mean age 63.1 [SD = 12.7]), 77% had New York Heart Association class I or II HF and 66% had HF with preserved ejection fraction. Common comorbidities were diabetes (35%), hypertension (64%), and sleep apnea (54%). Impaired vigilant attention was associated with non-White race, higher body mass index, less education, and more medical comorbidities. Self-reported cognitive impairment was associated with younger age, higher body mass index, and pulmonary disease. On adjusted analysis, significant risk factors for cognitive impairment included hypertension (OR 1.94), daytime sleepiness (OR 1.09), stress (OR 1.08), and quality of life (OR 0.12).

CONCLUSIONS

Impaired cognition is common among people with chronic HF and insomnia and associated with hypertension, daytime sleepiness, stress, and poor quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: Insomnia Self-management in Heart Failure; NCT#02,660,385.

A systematic review on the association of sleep-disordered breathing with cardiovascular pathology in adults

Sleep-disordered breathing (SDB) is characterized by repeated breathing pauses during sleep. The prevalence of SDB varies widely between studies. Some longitudinal studies have found an association of SDB with incident or recurrent cardiovascular events. We sought to systematically describe the current data on the correlation between SDB and cardiovascular pathology. Studies were included if they were original observational population-based studies in adults with clearly diagnosed SDB. The primary outcomes include all types of cardiovascular pathology. We carried out pooled analyses using a random effects model. Our systematic review was performed according to the PRISMA and MOOSE guidelines for systematic reviews and was registered with PROSPERO. In total, 2652 articles were detected in the databases, of which 76 articles were chosen for full-text review. Fourteen studies were focused on samples of an unselected population, and 8 studies were focused on a group of persons at risk for SDB. In 5 studies, the incidence of cardiovascular pathology in the population with SDB was examined. In total, 49 studies described SDB in patients with cardiovascular pathology. We found an association between SDB and prevalent /incident cardiovascular disease (pooled OR 1.76; 95% CI 1.38–2.26), and pooled HR (95% CI 1.78; 95% CI 1.34–2.45). Notably, in patients with existing SDB, the risk of new adverse cardiovascular events was high. However, the relationship between cardiovascular disease and SDB is likely to be bidirectional. Thus, more large-scale studies are needed to better understand this association and to decide whether screening for possible SDB in cardiovascular patients is reasonable and clinically significant.

Sleep Deficiency: A Symptoms Perspective: Exemplars from Chronic Heart Failure, Inflammatory Bowel Disease, and Breast Cancer

Sleep deficiency is associated with disabling daytime symptoms, including excessive daytime sleepiness (EDS) and fatigue. The purpose of this article is to discuss the contributions of sleep deficiency and sleep disorders to fatigue and EDS among people with chronic conditions. We use exemplars from the literature on chronic heart failure, inflammatory bowel disease, and breast cancer to (1) describe the prevalence of fatigue and EDS and their consequences; (2) examine the evidence for the contributions of sleep deficiency and sleep disorders to these symptoms; and (3) recommend implications for future research and practice.

Cognitive Behavioral Therapy for Insomnia has sustained effects on insomnia, fatigue, and function among people with chronic heart failure and insomnia: The HeartSleep Study

STUDY OBJECTIVES

Insomnia is common among adults with chronic heart failure (HF) and associated with daytime symptoms and decrements in function. The purpose of this randomized controlled trial (RCT) was to evaluate the sustained effects over one year of CBT-I (Healthy Sleep: HS) compared with HF self-management education (Healthy Hearts; attention control: HH) on insomnia severity, sleep characteristics, symptoms, and function among people with stable HF. The primary outcomes were insomnia severity, actigraph-recorded sleep efficiency, and fatigue.

METHODS

We randomized adults with stable HF with preserved or reduced ejection fraction who had at least mild insomnia (Insomnia severity index >7) in groups to HS or HH (4 sessions/8 weeks). We obtained wrist actigraphy and measured insomnia severity, self-reported sleep characteristics, symptoms (fatigue, excessive daytime sleepiness, anxiety, depression), and six-minute walk distance at baseline, within one month of treatment, and at 6 and 12 months. We used general linear mixed models (GLMM) and generalized estimating equations (GEE) to evaluate the effects.

RESULTS

The sample included 175 participants (M age = 63 +12.9 years; 43% women; 18% Black; 68% New York Heart Association Class II or II; 33%; LVEF < 45%) randomized to HS (n = 91) or HH (N = 84). HS had sustained effects on insomnia severity, sleep quality, self-reported sleep latency and efficiency, fatigue, excessive daytime sleepiness, and six-minute walk distance at 12 months.

CONCLUSIONS

CBT-I produced sustained improvements in insomnia, fatigue, daytime sleepiness, and objectively measured physical function among adults with chronic HF, compared with a robust HF self-management program that included sleep hygiene education.

Sleep apnoea in the elderly: a great challenge for the future

Due in part to overall improvements in health, the population of elderly individuals is increasing rapidly. Similarly, obstructive sleep apnoea (OSA) is both gaining increased recognition and also increasing due to the worldwide obesity epidemic. The overlap of OSA and aging is large, but there is strong plausibility for causation in both directions: OSA is associated with pathological processes that may accelerate aging and aging related processes; aging may cause physical and neurological changes that predispose to obstructive (and central) apnoea. In addition, the common symptoms (e.g. excessive daytime somnolence, defects in memory and cognition), possible physiological consequences of OSA (e.g. accelerated cardiovascular and cerebrovascular atherosclerosis), and changes in metabolic and inflammatory markers overlap with the symptoms and associated conditions seen in aging. There is also the possibility of synergy in the effects of these symptoms and conditions on quality of life, as well as a need to separate treatable consequences of OSA from age-related complaints. Taken together, the above make it essential to review the interaction of OSA and aging, both proven and suspected. The present review examines some aspects of what is known and points to the need for further investigation of the relationships, given the large number of potentially affected subjects.

Sleep disturbance in heart failure: A concept analysis

AIM

This concept analysis aims to analyze the concept of sleep disturbance (SD) in the context of heart failure (HF) to guide the development of a clearly defined definition.

BACKGROUND

The term "sleep disturbance" has been used in the literature to describe sleep problems and sleep disorders among individuals with HF. Environmental, physical, psychological, behavioral, and developmental factors complicate the phenomenon of SD in HF.

DESIGN

Walker and Avant's method was used for this concept analysis.

DATA SOURCE

Published literature from 2000 to 2020 was identified from electronic health profession-related databases. The current definition and usages of SD were abstracted from empirical work and electronic databases.

REVIEW METHODS

A focused review of abstracts and full text relating to SD in HF was performed. Studies featuring original data and peer-reviewed articles written in English were included to investigate the multifactorial contextual meaning of the concept.

RESULTS

SD in HF can be described as a condition in which individuals experience difficulty initiating and maintaining sleep, and difficulty continuing or resuming sleep due to frequent nocturnal arousals due to HF symptoms, sleep-disordered breathing, insomnia, and psychological burdens.

CONCLUSIONS

To evaluate SD in HF, clinicians must examine the underlying causes to provide the contextual meaning of the concept. A clearly defined and distinguishable concept of SD in HF provides a possibility for accurate measurements of sleep quality, exploring interventions, and evaluating outcomes.

Diagnostic accuracy and suitability of instruments that screen for obstructive sleep apnoea, insomnia and sleep quality in cardiac patients: a meta-analysis

BACKGROUND

A number of clinical guidelines recommend that all cardiac rehabilitation patients should be screened for potential sleep disorders with a validated screening instrument. There is currently no consensus on what specific tools should be used.

OBJECTIVE

To identify tools that are practical to use in the clinical environment and have high diagnostic accuracy.

METHODS

We systematically searched online databases to identify patient reported outcome instruments that have been used in published research studies to assess the likelihood of obstructive sleep apnoea (OSA) in cardiac patients. In studies that provided diagnostic data, these data were extracted and verified via an evidence-based diagnostic calculator. Where sufficient numbers of studies were available, a meta-analysis was conducted to determine pooled estimates of specificity, sensitivity and diagnostic odds ratios. Selected papers were qualitatively assessed using the Standards for Reporting Diagnostic accuracy studies (STARD).

RESULTS

Of the 21 instruments identified, six detected likelihood of OSA, two assessed daytime sleepiness, five assessed insomnia and eight examined sleep quality. A meta-analysis of 14 studies that assessed diagnostic accuracy of moderate OSA, revealed moderate sensitivity for the Berlin Questionnaire, Sens = 0.49 (95% CI 0.45-0.52) and good sensitivity for the Stop-BANG, Sens = 0.93 (95% CI 0.87-0.96) but poor specificity at standard cut-off criteria.

CONCLUSION

There are promising practical tools available to screen patients with OSA and other sleep disorders in cardiac rehabilitation settings, but specificity could be improved. Additional assessment of sleep quality may enhance prognostic ability with both OSA and insomnia screening.

Day-to-day Relationships between Physical Activity and Sleep Characteristics among People with Heart Failure and Insomnia

OBJECTIVE

Examine the bidirectional relationships between within-person day-to-day fluctuations in physical activity (PA) and sleep characteristics among people with heart failure (HF) and insomnia.

PARTICIPANTS

Ninety-seven community-dwelling adults [median age 61.9 (interquartile range 55.3,70.9) years, female 41%] with stable HF and insomnia (insomnia severity index >7).

METHODS

This sub-study longitudinally analyzed 15 consecutive days and nights of wrist actigraphy recordings, that were collected for baseline data prior to participation in a randomized controlled trial of cognitive behavioral therapy for insomnia. We used two-level mixed models of within- (daily) and between-participants variation to predict daytime PA counts/minutes from sleep variables (total sleep time, sleep efficiency) and predict sleep variables from PA.

RESULTS

PA counts/minutes were low compared to prior cohorts that did not have HF (209 (166,259)) and negatively associated with NYHA class (standardized coefficient β_s = -0.14, p < .01), age (β_s = -0.13, p = .01), comorbidities (β_s = -0.19, p < .01), and body mass index (β_s = -0.12, p = .04). After adjustment for all significant covariates, the within-participant association of total sleep time with next-day PA was estimated to be positive among participants with NYHA class II-IV HF (β_s = 0.09, p = .01), while the within-participant association of PA with same-night total sleep time was estimated to be positive among participants aged ≥60 years (β_s = 0.10, p = .03).

CONCLUSIONS

Depending upon age and HF class, daytime PA was associated with longer same-night sleep and/or longer sleep was associated with greater next-day PA. Among those with more advanced HF, realistic sleep improvements were associated with clinically meaningful PA gains the next day.

Perceived Stress, Subjective, and Objective Symptoms of Disturbed Sleep in Men and Women with Stable Heart Failure

Objective/Background: Sleep disturbance is prevalent among patients with heart failure (HF) and is associated with increased morbidity and mortality. Stress also affects health and quality of life among patients with cardiovascular disease and likely plays a prominent role in HF. However, little is known about the associations between stress and sleep among HF patients.Participants: One hundred fifty-three stable New York Heart Association (NYHA) Classification I-IV HF patients with at least low symptoms of insomnia (M_age:63.0 ± 12.8, 42% Women).Methods: We examined baseline stress, sleep disturbance, and sleep-related characteristics from a randomized controlled trial of cognitive behavioral therapy for insomnia, including the Perceived Stress Scale, Insomnia Severity Index, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Sleep Disturbance Questionnaire, Dysfunctional Beliefs about Sleep Scale, PROMIS Cognitive Ability, SF-36 Mental Health, and wrist actigraphy. We used Pearson correlations and general linear models to assess stress-sleep associations, including the potential moderating effects of sex and symptom severity (NYHA).Results: There were moderate-to-large correlations between stress and self-reported sleep disturbance, dysfunctional beliefs about sleep, cognitive ability, and mental health (p's < 0.01). High stress was associated with more objectively-measured (i.e., actigraph-assessed) awakenings and sleep fragmentation among women than men (β = - 0.04, p < 0.01; β = - 0.71, p = 0.04). Relationships between stress and objectively-measured sleep did not vary by symptom severity.Conclusions: Perceived stress is related to sleep disturbance among HF patients, and effects may be sex-dependent. Subsequent research should determine the temporal links between sleep and stress, and optimal opportunities for intervention among HF patients.

Impact of non-cardiovascular comorbidities on the quality of life of patients with chronic heart failure: a scoping review

PURPOSE

To determine the impact of non-cardiovascular comorbidities on the health-related quality of life (HRQoL) of patients with chronic heart failure (CHF).

METHODS

A scoping review of the scientific literature published between 2009 and 2019 was carried out. Observational studies which assessed the HRQoL of patients with CHF using validated questionnaires and its association with non-cardiovascular comorbidities were included.

RESULTS

The search identified 1904 studies, of which 21 fulfilled the inclusion criteria to be included for analysis. HRQoL was measured through specific, generic, or both types of questionnaires in 72.2%, 16.7%, and 11.1% of the studies, respectively. The most common comorbidities studied were diabetes mellitus (12 studies), mental and behavioral disorders (8 studies), anemia and/or iron deficiency (7 studies), and respiratory diseases (6 studies). Across studies, 93 possible associations between non-cardiovascular comorbidities and HRQoL were tested, of which 21.5% regarded anemia or iron deficiency, 20.4% mental and behavioral disorders, 20.4% diabetes mellitus, and 14.0% respiratory diseases. Despite the large heterogeneity across studies, all 21 showed that the presence of a non-cardiovascular comorbidity had a negative impact on the HRQoL of patients with CHF. A statistically significant impact on worse HRQoL was found in 84.2% of associations between mental and behavioral disorders and HRQoL (patients with depression had up to 200% worse HRQoL than patients without depression); 73.7% of associations between diabetes mellitus and HRQoL (patients with diabetes mellitus had up to 21.8% worse HRQoL than patients without diabetes mellitus); 75% of associations between anemia and/or iron deficiency and HRQoL (patients with anemia and/or iron deficiency had up to 25.6% worse HRQoL than between patients without anemia and/or iron deficiency); and 61.5% of associations between respiratory diseases and HRQoL (patients with a respiratory disease had up to 21.3% worse HRQoL than patients without a respiratory disease).

CONCLUSION

The comprehensive management of patients with CHF should include the management of comorbidities which have been associated with a worse HRQoL, with special emphasis on anemia and iron deficiency, mental and behavioral disorders, diabetes mellitus, and respiratory diseases. An adequate control of these comorbidities may have a positive impact on the HRQoL of patients.

Sleep apnea screening instrument evaluation and novel model development and validation in the paroxysmal atrial fibrillation population

Standard sleep apnea (SA) screening instruments perform suboptimally in the atrial fibrillation (AF) population. We evaluated and optimized common OSA screening tools in the AF population. Participants of the Sleep Apnea and Atrial Fibrillation Biomarkers and Electrophysiologic Atrial Triggers (SAFEBEAT, NCT02576587) age (±5 years)-, sex-, body mass index (BMI ± 5 kg/m²)-matched case control study (n = 150 each group) completed concurrent questionnaires and overnight polysomnography. Models based on STOP, STOP-BANG, Berlin, NoSAS and Epworth Sleepiness Scale and also models with STOP-BANG predictors with resting heart rate or left atrial volume were constructed. “Best subset” analysis was used to select a predictor subset for evaluation. We assessed test performance for two outcome thresholds: apnea-hypopnea index (AHI) ≥ 5 and AHI ≥ 15. Paroxysmal AF participants were: 61.3 ± 12.1 years, BMI = 31.2 ± 6.6 kg/m² with median AHI = 11.8(IQR: 3.8, 24.5); 65 (43.3%) with AHI ≥ 15. Only STOP and STOP-BANG did not perform worse in AF relative to controls. For AHI ≥ 15, STOP-BANG (AUC 0.71, 95%CI:0.55–0.85) did not perform as well as NABS – a composite of neck circumference, age, and BMI as continuous variables and snoring (AUC 0.88, 95%CI:0.76–0.96). Optimal model for AHI ≥ 15 was NABS (sensitivity = 45%, specificity = 97%). For AHI ≥ 5, NABS was also the best performing (AUC 0.82, 95%CI:0.68–0.92, sensitivity = 78%, specificity = 67%). We identify a novel, short-item SA screening instrument for use in paroxysmal AF, i.e. NABS, with improved discriminative ability compared to commonly-used instruments. Further validation studies are needed to assess utility in other AF subtypes.

Trial registration: clinicaltrials.gov NCT02576587.

Daytime and Nighttime Sleep Characteristics and Pain Among Adults With Stable Heart Failure

BACKGROUND

Pain and sleep disturbance are common among patients with heart failure (HF) and are associated with symptom burden, disability, and poor quality of life. Little is known about the associations between specific sleep characteristics and pain in people with HF.

OBJECTIVE

The aim of this study was to describe the relationships between nocturnal sleep characteristics, use of sleep medication, and daytime sleep characteristics and pain among people with HF.

METHODS

We conducted a cross-sectional study of stable participants with HF. We administered the SF36 Bodily Pain Scale, Pittsburgh Sleep Quality Index, and Sleep Habits Questionnaire and obtained 3 days of wrist actigraphy and 1 night of home unattended polysomnography. We conducted bivariate analyses and generalized linear models.

RESULTS

The sample included 173 participants (mean [SD] age, 60 [16.1] years; 65.3% [n = 113] male). Insomnia symptoms (P = .0010), sleep duration (P = .0010), poor sleep quality (P = .0153), use of sleep medications (P = .0170), napping (P = .0029), and daytime sleepiness (P = .0094) were associated with increased pain. Patients with the longest sleep duration, who also had insomnia, had more pain (P = .0004), fatigue (P = .0028), daytime sleepiness (P = .0136), and poorer sleep quality (P < .0001) and took more sleep medications (P = .0029) than did those without insomnia.

CONCLUSIONS

Pain is associated with self-reported poor sleep quality, napping, daytime sleepiness, and use of sleep medication. The relationship between pain and sleep characteristics differs based on the presence of insomnia and sleep duration. Studies are needed to evaluate the causal relationships between sleep and pain and test interventions for these cooccurring symptoms.

Advances in accelerometry for cardiovascular patients: a systematic review with practical recommendations

Aims

Accelerometers are becoming increasingly commonplace for assessing physical activity; however, their use in patients with cardiovascular diseases is relatively substandard. We aimed to systematically review the methods used for collecting and processing accelerometer data in cardiology, using the example of heart failure, and to provide practical recommendations on how to improve objective physical activity assessment in patients with cardiovascular diseases by using accelerometers.

Methods and results

Four electronic databases were searched up to September 2019 for observational, interventional, and validation studies using accelerometers to assess physical activity in patients with heart failure. Study and population characteristics, details of accelerometry data collection and processing, and description of physical activity metrics were extracted from the eligible studies and synthesized. To assess the quality and completeness of accelerometer reporting, the studies were scored using 12 items on data collection and processing, such as the placement of accelerometer, days of data collected, and criteria for non‐wear of the accelerometer. In 60 eligible studies with 3500 patients (of those, 536 were heart failure with preserved ejection fraction patients), a wide variety of accelerometer brands (n = 27) and models (n = 46) were used, with Actigraph being the most frequent (n = 12), followed by Fitbit (n = 5). The accelerometer was usually worn on the hip (n = 32), and the most prevalent wear period was 7 days (n = 22). The median wear time required for a valid day was 600 min, and between two and five valid days was required for a patient to be included in the analysis. The most common measures of physical activity were steps (n = 20), activity counts (n = 15), and time spent in moderate‐to‐vigorous physical activity (n = 14). Only three studies validated accelerometers in a heart failure population, showing that their accuracy deteriorates at slower speeds. Studies failed to report between one and six (median 4) of the 12 scored items, with non‐wear time criteria and valid day definition being the most underreported items.

Conclusions

The use of accelerometers in cardiology lacks consistency and reporting on data collection, and processing methods need to be improved. Furthermore, calculating metrics based on raw acceleration and machine learning techniques is lacking, opening the opportunity for future exploration. Therefore, we encourage researchers and clinicians to improve the quality and transparency of data collection and processing by following our proposed practical recommendations for using accelerometers in patients with cardiovascular diseases, which are outlined in the article.

Insomnia and Insomnia Symptoms in Persons With Heart Failure: An Integrative Review

BACKGROUND/OBJECTIVE

Insomnia and insomnia symptoms are highly prevalent in persons with heart failure (HF), and they are associated with several untoward outcomes. The purpose of this integrative review is to describe the correlates, predictors, and outcomes of insomnia and insomnia symptoms in persons with HF.

METHODS

Using integrative review methods, an extensive electronic search of 5 databases was conducted for the period of 2000-2019. Sixteen studies were identified that met the inclusion criteria for review and investigated insomnia or insomnia symptoms in HF.

RESULTS

Various sociodemographic factors, chronic comorbidities, clinical factors, and cognitive-behavioral factors are correlates and predictors of insomnia and insomnia symptoms in persons with HF. Depression, fatigue, daytime sleepiness, poor self-reported physical functioning, decreased exercise capacity, cardiac events, and poor health-related quality of life are significant outcomes of insomnia and insomnia symptoms in persons with HF. The associations of insomnia and insomnia symptoms with age, sex, sleep-disordered breathing, and cognition were not consistent across all studies.

CONCLUSION

Larger studies with diverse age and race groups as well as longitudinal studies and designs that test mediation effects are needed to disentangle complex relationships between insomnia and insomnia symptoms and several of their potential predictors and correlates in HF.

Rest-activity rhythms, daytime symptoms, and functional performance among people with heart failure

Sleep disturbance and decreased daytime activity are well-described among people with chronic heart failure (HF) who suffer from disabling daytime symptoms and poor function. Alterations in the circadian rhythmicity of rest-activity may also be associated with these outcomes. However, little is known about the associations between rest-activity rhythms (RARS), symptoms, and functional performance or the extent to which they are explained by sleep characteristics among people with HF. The purpose of this study is to evaluate parametric and non-parametric circadian characteristics of RARs and the associations between these variables, daytime symptoms, and functional performance among patients with stable heart failure (HF). We recruited adults with stable HF from HF disease management programs. Participants wore wrist actigraphs for 3 d, completed one night of unattended polysomnography and the Six Minute Walk Test, and reported daytime symptoms and physical function. We performed cosinor, non-parametric, and spectral analyses to evaluate the rest-activity rhythms and computed bivariate correlations between the rest-activity rhythm, demographics, daytime symptoms, and functional performance. We conducted multiple regression analysis to examine how RARs contribute to daytime symptoms and functional performance after controlling for insomnia and covariates. The sample included 135 participants [Mean age = 60.6 (16.1) y, n = 88 (65.2%) male]. Older age, greater comorbidity, and poorer New York Heart Association (NYHA) Class, and more EEG arousals were associated with greater intra-daily variability of the RAR. More robust rhythmicity represented by the circadian quotient was associated with better NYHA class and less sleep fragmentation. A higher circadian quotient was significantly associated with lower fatigue, depression, and sleepiness, and better functional performance after controlling for insomnia and clinical and demographic characteristics. Circadian parameters of rest-activity are associated with symptoms and functional performance among people with HF independent of insomnia or sleep disordered breathing. Interventions targeted at improving the stability and strength of rest-activity rhythms may improve symptom and functional outcomes for these patients.

Effects of Cognitive Behavioral Therapy for Insomnia on Sleep, Symptoms, Stress, and Autonomic Function Among Patients With Heart Failure

Background: Insomnia is common among patients with stable heart failure (HF) and associated with inflammation and altered autonomic function. Purpose: The purposes of this study were to examine the effects of cognitive behavioral therapy for insomnia (CBT-I) on the Hypothalamic Pituitary (HPA) Axis, autonomic function, inflammation, and circadian rhythmicity and the associations between these biomarkers and insomnia, sleep characteristics, symptoms, functional performance, and sleep-related cognitions. Methods: We conducted a subanalysis of a pilot randomized controlled trial (RCT, NCT02827799) whose primary aim was to test the effects of CBT-I on insomnia. We randomized 51 patients with stable Class II-IV HF to CBT-I (n = 30) or attention control (n = 21). Participants completed wrist actigraphy and self-reported insomnia severity, sleep characteristics, sleep-related cognitions, daytime symptoms, and functional performance. We measured day and nighttime urinary free cortisol, melatonin sulfate, epinephrine, and norepinephrine at baseline, and two weeks after CBT-I and computed general linear models and partial correlations. Results: CBT-I had no effects on the biomarkers, but there were statistically significant negative cross-sectional correlations between the ratio of day and night urinary free cortisol and sleep disturbance, anxiety, fatigue, depression, and negative sleep cognitions. Increases in the ratio between day and night cortisol were associated with statistically significant improvements in fatigue, depression, sleep duration, and sleep-related cognitions. Conclusions: Biomarkers of stress and autonomic function are associated with sleep, sleep-related symptoms, and cognitions among people with chronic HF. Future studies are needed to identify potential causal relationships and the impact of sleep interventions.

Physiological and Psychological Stress in Patients Living With a Left Ventricular Assist Device

Patients with a left ventricular assist device (LVAD) commonly experience psychological distress post-implantation, but physiological stress and differences by implant strategy remain unstudied. This study describes indicators of physiological (salivary cortisol, C-reactive protein, sleep quality) and psychological (perceived stress, depression, and fatigue) stress by implant strategy and examines relationships between stress and outcomes (quality of life [QOL] and functional status). Prospective, cross-sectional data were collected from patients ≥3 months post-LVAD implantation (n = 44), and descriptive statistics and logistic regression were used. The study sample was average age 57.7 ± 13 years, mostly male (73%), married (70.5%), and racially diverse. Median LVAD support was 18.2 months. Most had normal cortisol awakening response and fair sleep quality, with moderate psychological stress. There were no differences in stress by implant strategy. Normal cortisol awakening response was correlated with low depressive symptoms. Sleep quality and psychological stress were associated with QOL, whereas cortisol and C-reactive protein levels were associated with functional status. This is the first report of salivary biomarkers and stress in LVAD outpatients. Future research should examine physiological and psychological stress and consider potential clinical implications for stress measurement for tailored approaches to stress management in this population.

Sleepless nights and sleepy days: a qualitative study exploring the experiences of patients with chronic heart failure and newly verified sleep-disordered breathing

BACKGROUND

Sleep-disordered breathing, including obstructive sleep apnoea and central sleep apnoea, is a common disorder among patients with chronic heart failure. Obstructive sleep apnoea is often treated with continuous positive airway pressure, but central sleep apnoea lacks a clear treatment option. Knowledge of how sleep-disordered breathing is experienced (e.g. difficulties and care needs) and handled (e.g. self-care actions) by the patients is limited, but needed, to provide patient-centred care.

AIM

To explore how newly verified sleep-disordered breathing is experienced by patients with chronic heart failure.

METHODS

Data were collected through semi-structured interviews and analysed with qualitative content analysis. Seventeen participants (14 men, three women), mean age 60 years (range 41-80) diagnosed with chronic heart failure and objectively verified sleep-disordered breathing (nine obstructive, seven central and one mixed) were strategically selected from heart failure outpatient clinics at two Norwegian university hospitals.

RESULTS

Patients with chronic heart failure and newly verified sleep-disordered breathing (SDB) described experiences of poor sleep that had consequences for their daily life and their partners. Different self-care strategies were revealed, but they were based on 'common sense' and were not evidence-based. The awareness of having SDB was varied; for some, it gave an explanation to their trouble while others were surprised by the finding.

CONCLUSION

Patients with chronic heart failure and sleep-disordered breathing experienced reduced sleep quality, influencing their daily life. Possible underlying causes of disrupted sleep, such as sleep-disordered breathing, should be identified to establish proper patient-centred treatment strategies. There is a need for new strategies to approach patients with chronic heart failure (i.e. those with central sleep apnoea) who are not subject to continuous positive airway pressure treatment for their sleep-disordered breathing.

Mechanisms of reduced sleepiness symptoms in heart failure and obstructive sleep apnea

Patients with both heart failure and obstructive sleep apnea often have poor, repeatedly disrupted sleep, and yet they frequently do not complain of excessive daytime sleepiness. Understanding this lack of perceived sleepiness is crucial for the case identification and treatment of obstructive sleep apnea in the heart failure population at high risk of this disease, especially given the association between untreated obstructive sleep apnea and mortality among patients with heart failure. In this review, we present epidemiologic evidence concerning the lack of sleepiness symptoms in heart failure and obstructive sleep apnea, explore possible mechanistic explanations for this relationship, assess the benefits of treatment in this population, discuss implications for clinical practice and explore directions for future research.

Sleep quality and daytime sleepiness are not associated with cognition in heart failure

BACKGROUND

Individuals with heart failure (HF) exhibit comorbid impairments in both sleep and cognitive performance. Sleep quality has been associated with impaired cognitive performance in HF patients, but reports are inconsistent. In this study, we examined associations between sleep quality, daytime sleepiness, and cognitive function in HF.

METHODS AND RESULTS

Participants were 267 (age = 69.1 ± 9.3) mostly Caucasian (74.9%), male (59.6%) stable HF patients recruited from outpatient settings. This cross-sectional study was a secondary analysis of a prospective observational study. Cognitive function domains assessed included: global cognitive function, attention, memory, and executive function. Sleep quality and daytime sleepiness were assessed using the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS), respectively. Separate multiple hierarchical linear regressions were conducted to determine associations between cognitive function and sleep quality and daytime sleepiness, after controlling for sex, New York Heart Association (NYHA) class, education, depressive symptoms, and medical comorbidities. Cognitive function was not associated with sleep quality or daytime sleepiness after alpha inflation corrections were applied.

CONCLUSIONS

Cognitive function in HF is not associated with sleep quality or daytime sleepiness; other factors may exert greater influence on cognitive performance.

Melatonin and Sleep in Preventing Hospitalized Delirium: A Randomized Clinical Trial

PURPOSE

Studies suggest that melatonin may prevent delirium, a condition of acute brain dysfunction occurring in 20%-30% of hospitalized older adults that is associated with increased morbidity and mortality. We examined the effect of melatonin on delirium prevention in hospitalized older adults while measuring sleep parameters as a possible underlying mechanism.

METHODS

This was a randomized clinical trial measuring the impact of 3 mg of melatonin nightly on incident delirium and both objective and subjective sleep in inpatients age ≥65 years, admitted to internal medicine wards (non-intensive care units). Delirium incidence was measured by bedside nurses using the confusion assessment method. Objective sleep measurements (nighttime sleep duration, total sleep time per 24 hours, and sleep fragmentation as determined by average sleep bout length) were obtained via actigraphy. Subjective sleep quality was measured using the Richards Campbell Sleep Questionnaire.

RESULTS

Delirium occurred in 22.2% (8/36) of subjects who received melatonin vs in 9.1% (3/33) who received placebo (P = .19). Melatonin did not significantly change objective or subjective sleep measurements. Nighttime sleep duration and total sleep time did not differ between subjects who became delirious vs those who did not, but delirious subjects had more sleep fragmentation (sleep bout length 7.0 ± 3.0 vs 9.5 ± 5.3 min; P = .03).

CONCLUSIONS

Melatonin given as a nightly dose of 3 mg did not prevent delirium in non-intensive care unit hospitalized patients or improve subjective or objective sleep.

Discrepancy between wrist-actigraph and polysomnographic measures of sleep in patients with stable heart failure and a novel approach to evaluating discrepancy

Wrist-actigraphy is often used to measure sleep characteristics in a variety of populations, but discrepancies between actigraphic and polysomnographic measures have been noted in populations experiencing poor sleep quality. The purpose of this study is to examine the discrepancy between these measures and risk factors for discrepancy in people with heart failure using a novel index. We used sleep measures simultaneously recorded by actigraphy and polysomnography, and clinical data from a cross-sectional study of 155 patients with heart failure (age = 60.5 [16.1] years; 65.2% male) recruited from evidence-based heart failure disease management programmes. The discrepancy and consistency between the two measures were evaluated using Bland-Altman plots, intra-class correlations and a newly developed index that represents activity counts in wake episodes. Overall, participants had short total sleep time (327.7 [95.9] min) and poor sleep efficiency (71.3 [16.0]%) on polysomnography. The discrepancies between sleep measures were small in patients less than 60 years old, and there was excellent consistency (intra-class correlation = 0.81) compared with older patients who had poorer consistency (intra-class correlation = 0.53) on total sleep time. Higher daytime motor activity, poor sleep quality and more severe insomnia were associated with smaller discrepancies in older, but not younger, patients, and associations were more sensitively detected by the new index. These findings suggest the importance of aging, disability and co-morbidity that may influence motor activity from which sleep estimates are scored with actigraphy. The new index may be useful in identifying factors associated with the correspondence between actigraphy and polysomnography.

Identification and Treatment of Central Sleep Apnoea: Beyond SERVE-HF

Central sleep apnoea (CSA) occurs in a large proportion of HF patients. CSA has clear detrimental effects, resulting in intermittent hypoxia and sympathetic activation, and is associated with significant morbidity and mortality. Treatment options are limited following the results of a recent trial in which adaptive servo-ventilation resulted in an increase in cardiovascular mortality. Ongoing studies utilising other forms of positive airway pressure may provide additional insight into the results of this trial. A new neurostimulation therapy, phrenic nerve stimulation, has offered a new physiological approach to the treatment of CSA. This therapy has resulted in improvements in the severity of disease and quality of life.

Sleep disordered breathing in older adults with heart failure with preserved ejection fraction

Heart failure in older adults is frequently accompanied by sleep disordered breathing (SDB). Treatment of SDB in persons with heart failure with preserved ejection fraction (HFpEF) is unclear because most data is on heart failure with reduced ejection fraction (HFrEF). The purpose of this paper was to evaluate studies that report on the effects of positive airway pressure on patient outcomes in older adults with HFpEF and comorbid SDB. A search of the literature found six data-based studies (N = 36 to 126). Treatment with positive airway pressure reduced nighttime SDB symptoms and improved daytime functional status in persons with HFPEF and SDB (New York Heart Association Functional Class: effect sizes = -0.67 to -1.60). Limitations (i.e. only two studies were randomized controlled trials, small sample sizes, and women were under-represented) suggest that additional evidence is needed to guide treatment of SDB in older adults with HFpEF.

Sleep Disturbance, Daytime Symptoms, and Functional Performance in Patients With Stable Heart Failure: A Mediation Analysis

BACKGROUND

Sleep disturbance is common among patients with heart failure (HF) who also experience symptom burden and poor functional performance.

OBJECTIVE

We evaluated the extent to which sleep-related, daytime symptoms (fatigue, excessive daytime sleepiness, and depressive symptoms) mediate the relationship between sleep disturbance and functional performance among patients with stable HF.

METHODS

We recruited patients with stable HF for this secondary analysis of data from a cross-sectional, observational study. Participants completed unattended ambulatory polysomnography from which the Respiratory Disturbance Index was calculated, along with a Six-Minute Walk Test, questionnaires to elicit sleep disturbance (Pittsburgh Sleep Quality Index, Insomnia Symptoms from the Sleep Habits Questionnaire), daytime symptoms (Center for Epidemiologic Studies Depression Scale, Global Fatigue Index, Epworth Sleepiness Scale), and self-reported functional performance (Medical Outcomes Study SF36 V2 Physical Function Scale). We used structural equation modeling with latent variables for the key analysis. Follow-up, exploratory regression analysis with bootstrapped samples was used to examine the extent to which individual daytime symptoms mediated effects of sleep disturbance on functional performance after controlling for clinical and demographic covariates.

RESULTS

The sample included 173 New York Heart Association Class I-IV HF patients (n = 60/34.7% women; M = 60.7, SD = 16.07 years of age). Daytime symptoms mediated the relationship between sleep disturbance and functional performance. Fatigue and depression mediated the relationship between insomnia symptoms and self-reported functional performance, whereas fatigue and sleepiness mediated the relationship between sleep quality and functional performance. Sleepiness mediated the relationship between the respiratory index and self-reported functional performance only in people who did not report insomnia.

CONCLUSIONS

Daytime symptoms explain the relationships between sleep disturbance and functional performance in stable HF.

Sleep duration and quality in heart failure patients

PURPOSE

Sleep-disordered breathing (SDB) is highly prevalent in patients with heart failure and reduced left ventricular ejection fraction (HF-REF). SDB is classified as predominant obstructive (OSA) or central (CSA) and may alter sleep duration, sleep quality, and quality of life. This study describes sleep quality and duration in well-characterized cohorts of these patients.

METHODS

Two hundred fifty consecutive patients with HF-REF (NYHA class ≥II, ejection fraction ≤45%) underwent cardiac and pulmonary examination, plus full attended in-hospital overnight polysomnography (PSG). PSG recordings were performed according to current recommendations and underwent independent, blinded analysis at a core laboratory.

RESULTS

Patients with HF-REF and CSA were older and had more impaired cardiac function compared to those with OSA. With respect to sleep parameters, patients with CSA spent more time in bed than those with OSA (468 ± 52 vs 454 ± 46 min, p = 0.021) while sleep efficiency was lower (67 ± 14 vs 72 ± 13% of total sleep time (TST), p = 0.008). In addition, CSA patients spent more time awake after sleep onset (101 ± 61 vs 71 ± 46 min, p = 0.001) and had more stage N1 (light) sleep (33 ± 19 vs 28 ± 16% of TST, p = 0.017). Overall, the proportion of sleep spent in N3 (slow-wave/deep) sleep in HF-REF patients with SDB was low (4.1 ± 6.3% of TST) compared with healthy adults.

CONCLUSIONS

HF-REF patients with CSA compared to OSA have worse sleep efficiency and quality. This could result in less restorative sleep, changes in sympathovagal balance, and impaired resetting of important reflexes, which might contribute to worse cardiovascular outcomes in HF-REF patients with SDB.

A Narrative Review of How Sleep-Related Breathing Disorders and Cardiovascular Diseases Are Linked: An Update for Advanced Practice Registered Nurses

PURPOSE/OBJECTIVES

Sleep-related breathing disorders (SRBDs), including obstructive sleep apnea and central sleep apnea, are common among patients with cardiovascular disease (CVD), but clinicians often do not pay enough attention to SRBDs. The purpose of this narrative review is to update advanced practice registered nurses on the literature focusing on the relationship between SRBDs and CVD (eg, hypertension, heart failure, coronary artery disease, arrhythmias, and stroke) and on treatments that can improve SRBDs in patients with CVD.

DESCRIPTION OF THE PROJECT

We conducted an electronic search of the literature published between 1980 and 2016 from PubMed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Academic Search Premier, and related health resource Web sites to address the aims of this study.

OUTCOMES

Fifty-six primary research articles (42 observational studies and 14 experimental and quasi-experimental studies) were selected based on our study aims and inclusion criteria. The studies revealed that individuals with CVD are at a greater risk for SRBDs and that SRBDs can worsen CVD. The findings from the studies also suggest that positive airway treatment could improve both SRBDs and CVD.

CONCLUSIONS

This review found a close relationship between SRBDs and CVD. Advanced practice registered nurses are in key positions to identify and help patients manage SRBDs. In particular, advanced practice registered nurses can educate staff and establish standards of practice to improve outcomes for patients with CVD.

Lateralized Resting-State Functional Brain Network Organization Changes in Heart Failure

Heart failure (HF) patients show brain injury in autonomic, affective, and cognitive sites, which can change resting-state functional connectivity (FC), potentially altering overall functional brain network organization. However, the status of such connectivity or functional organization is unknown in HF. Determination of that status was the aim here, and we examined region-to-region FC and brain network topological properties across the whole-brain in 27 HF patients compared to 53 controls with resting-state functional MRI procedures. Decreased FC in HF appeared between the caudate and cerebellar regions, olfactory and cerebellar sites, vermis and medial frontal regions, and precentral gyri and cerebellar areas. However, increased FC emerged between the middle frontal gyrus and sensorimotor areas, superior parietal gyrus and orbito/medial frontal regions, inferior temporal gyrus and lingual gyrus/cerebellar lobe/pallidum, fusiform gyrus and superior orbitofrontal gyrus and cerebellar sites, and within vermis and cerebellar areas; these connections were largely in the right hemisphere (p<0.005; 10,000 permutations). The topology of functional integration and specialized characteristics in HF are significantly changed in regions showing altered FC, an outcome which would interfere with brain network organization (p<0.05; 10,000 permutations). Brain dysfunction in HF extends to resting conditions, and autonomic, cognitive, and affective deficits may stem from altered FC and brain network organization that may contribute to higher morbidity and mortality in the condition. Our findings likely result from the prominent axonal and nuclear structural changes reported earlier in HF; protecting neural tissue may improve FC integrity, and thus, increase quality of life and reduce morbidity and mortality.

Contributions of Comorbid Diabetes to Sleep Characteristics, Daytime Symptoms, and Physical Function Among Patients With Stable Heart Failure

BACKGROUND

Diabetes mellitus (DM) and heart failure (HF) are often comorbid. Sleep disturbances, poor physical functioning, and high levels of daytime symptoms are prevalent and contribute to poor quality of life in both populations. However, little is known about the independent and additive effects of comorbid DM on sleep, physical function, and daytime symptoms among patients with HF.

OBJECTIVE

The aim of this study was to investigate the extent to which comorbid DM confers independent and additive effects on sleep disturbance, physical functioning, and symptoms among patients with stable HF.

METHODS

This secondary analysis was conducted on a sample of 173 stable class II to IV HF patients. Self-report and polysomnography were used to measure sleep quality, objective sleep characteristics, and sleep-disordered breathing. Physical function measures included wrist actigraphy, the 6-minute walk test (6MWT), and the Medical Outcomes Study 36-item Short Form physical component summary score. Fatigue, sleepiness, and depression were also measured. Univariate analyses and hierarchical regression models were computed.

RESULTS

The sample included 173 (n = 119/68% HF and n = 54/32% HF plus DM) patients (mean [SD] age, 60.4 [16.1] years). In analyses adjusted for age, gender, body mass index, and New York Heart Association classification, the HF patients with DM had longer sleep latency and spent a greater percentage of time awake after sleep onset than the HF patients who did not have DM (all P < 0.05). There were no statistically significant differences in Respiratory Disturbance Index or self-reported sleep quality. Sleep duration was low in both groups. The patients with DM had shorter 6MWT distance, lower ratio of daytime to nighttime activity, as well as lower general health and self-reported physical function. Hierarchical regression models revealed that age and DM were the only significant correlates of the sleep variables, whereas age, gender, New York Heart Association class, and DM were all associated with 6MWT distance.

CONCLUSIONS

Comorbid DM contributes independent and additive effects on sleep disturbances and poor physical functioning in patients with stable HF.

Determinants of Behavioral Alertness in Adults with Heart Failure

STUDY OBJECTIVES

The primary objective of this study was to describe characteristics of sleep across the three domains of sleep quality, daytime sleepiness, and behavioral alertness in community-dwelling adults with heart failure. The secondary objective was to identify modifiable factors associated with behavioral alertness.

METHODS

A sample of 280 adults with chronic heart failure was enrolled. Widely used, validated, and sensitive measures of sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness Scale, Stanford Sleepiness Scale), and behavioral alertness (Psychomotor Vigilance Test [PVT]) were collected at baseline, 3 and 6 months. Sociodemographic and clinical characteristics, including exercise, were measured at baseline.

RESULTS

Participants were primarily male and functionally compromised with a mean left ventricular ejection fraction of 35 percent. The majority of the sample (73%) reported poor sleep quality. The mean (± SD) Epworth Sleepiness Scale score was low (7.0 ± 4.6), indicating they did not perceive daytime sleepiness. In contrast, behavioral alertness was relatively poor as evidenced by a slow PVT mean response time (3.09 ± 0.76). Participants who reported exercising at least one hour in the past week were more alert and had faster response times than those reporting no exercise.

CONCLUSIONS

Although sleep quality was poor and behavioral alertness was compromised, these heart failure patients did not feel sleepy. Exercise may help to promote behavioral alertness and reduce daytime sleepiness in adults with heart failure.

Feasibility and Efficacy of a Self-Management Intervention for Insomnia in Stable Heart Failure

BACKGROUND

Chronic insomnia is common among patients with heart failure (HF) and may contribute to fatigue and poor function. However, to date there have been no randomized controlled trials focused on treatment of insomnia or daytime symptoms in this population.

OBJECTIVES

The purpose of this study was to examine the preliminary efficacy, feasibility, and acceptability of a self-management intervention (cognitive behavioral therapy [CBT-I]) for insomnia among patients with stable HF.

METHODS

We conducted a pilot randomized controlled trial (RCT) in which patients with stable Class I-III HF (n = 25/52.1% women; mean age = 59 ± 14.8 years) were randomized in groups to CBT-I (n = 29) or an attention control condition (HF self-management with sleep hygiene; n = 19). Participants completed 2 weeks of wrist actigraphy, the insomnia severity index, and measures of fatigue, depression, sleepiness, and functional performance at baseline and follow-up. We computed the size of the effects on the dependent variables and used MANOVA to evaluate the effects of CBT-I on insomnia and fatigue.

RESULTS

CBT-I was feasible and acceptable and had a statistically significant effect on insomnia and fatigue, while controlling for the effects of comorbidity and age.

CONCLUSIONS

CBT-I has short-term efficacy as a treatment for chronic insomnia among patients with stable HF. Future studies are needed to address its sustained effects.

Cognitive Behavioral Therapy for Insomnia in the Context of Cardiovascular Conditions

Cardiovascular disease (CVD) is the leading cause of death worldwide and is associated with high levels of morbidity, disability and poor quality of life. The prevalence of insomnia symptoms and diagnosis of insomnia are high among those with CVD. Although insomnia appears to be important to CVD, less is known about the effects of insomnia treatment on important biological, sleep, symptom, quality of life, functional and morbidity or mortality outcomes in people with or at-risk for CVD. The purposes of this paper are to review the literature on the effects of CBT-I on insomnia, sleep, daytime symptoms, function, and biological outcomes in the context of CVD and to suggest implications for future research and practice. Limited available evidence suggests that CBT-I improves biomarkers that may contribute to CVD risk. CBT-I shows promise as a way to improve cardiovascular morbidity associated with the negative biological consequences of chronic insomnia, as well as symptom burden, functional performance and quality of life in the large population of people who are living with chronic CVD and insomnia. Additional research is needed to answer basic questions about short and long term outcomes, the role of biomarkers, and optimal delivery methods of CBT-I in cardiac conditions.

Should All Congestive Heart Failure Patients Have a Routine Sleep Apnea Screening? Pro

Sleep-disordered breathing (SDB) is highly prevalent in heart failure (HF) patients. These breathing disturbances are independent predictors of increased morbidity and comorbid conditions that improve with SDB treatment. Considering the overlap between SDB-related and HF clinical symptoms reported by patients, objective tests need to be conducted for a diagnosis to be firmly established and to determine the type and severity of SDB that will dictate treatment alternatives. Considering the high success rate and diagnostic value of ambulatory monitoring techniques, they represent a practical, cost-effective, and accurate alternative to diagnosing SDB in HF patients.

Sleep-disordered Breathing in Heart Failure - Current State of the Art

Sleep-disordered breathing (SDB), either obstructive sleep apnoea (OSA) or central sleep apnoea (CSA)/Cheyne-Stokes respiration (CSR) and often a combination of the two, is highly prevalent in patients with heart failure (HF), is associated with reduced functional capacity and quality of life, and has a negative prognostic impact. European HF guidelines identify that sleep apnoea is of concern in patients with HF. Continuous positive airway pressure is the treatment of choice for OSA, and adaptive servoventilation (ASV) appears to be the most consistently effective therapy for CSA/CSR while also being able to treat concomitant obstructive events. There is a growing body of evidence that treating SDB in patients with HF, particularly using ASV for CSA/CSR, improves functional outcomes such as HF symptoms, cardiac function, cardiac disease markers, exercise tolerance and quality of life. However, conflicting results have been reported on 'hard' outcomes such as mortality and healthcare utilisation, and the influence of effectively treating SDB, including CSA/CSR, remains to be determined in randomised clinical trials. Two such trials (SERVE-HF and ADVENT-HF) in chronic stable HF and another in post-acute decompensated HF (CAT-HF) are currently underway.

Is sleep quality related to cognition in individuals with heart failure?

OBJECTIVE

To examine how self-reported sleep quality and daytime symptoms are associated with selected domains of cognitive function among individuals with heart failure (HF).

BACKGROUND

HF patients suffer from poor sleep quality and cognitive decline. The relationship between sleep and cognition has not been well documented among individuals with HF.

METHODS

In this descriptive, cross-sectional study, 68 individuals with HF (male: 63%, mean age = 72 years, SD = 11) completed sleep questionnaires and a neuropsychological battery.

RESULTS

Participant had mean Pittsburgh Sleep Quality Index score of 5.04 (SD = 2.8). Regression analyses demonstrated neither sleep quality or excessive daytime sleepiness (EDS) were related to cognitive function, but daytime dysfunction was related to lower letter fluency and attention index.

CONCLUSION

Contrary to some earlier reports, subjective sleep and EDS in this group of individuals was not associated with cognitive decline.

The relationship between pain, fatigue, depression and functional performance in stable heart failure

OBJECTIVE

Evaluate the relationship between pain, fatigue, depression, demographic, clinical, and functional variables in stable heart failure (HF).

BACKGROUND

Pain, fatigue and depression are common in HF. Little is known about the relationship between pain, fatigue and depression and functional measures in this population.

METHODS

Secondary data analysis of a cross sectional study of 173 stable HF patients. Associations between clinical and demographic factors, pain (SF-36), depression (CES-D), and fatigue (MAF) to functional performance and capacity (SF-36 role limitations due to physical functioning and 6-Minute Walk Test) were evaluated using hierarchical multiple regressions.

RESULTS

The sample was 65% male with a mean age of 60. Fifty-seven percent (n = 100) had pain, 54% (n = 94) had fatigue, and 46% (n = 79) had depression. Pain, depression and fatigue were negatively associated with functional performance but not functional capacity when controlling for demographic and clinical covariates.

CONCLUSIONS

Pain, fatigue and depression were associated with decreased functional performance in stable HF. Symptom management interventions are needed in HF.

Clinical predictors of sleep apnoea in heart failure outpatients

BACKGROUND

Sleep-disordered breathing (SDB) is common in heart failure patients. Many of them still remain undiagnosed. The aim of this study was to detect clinical predictors of sleep apnoea which may help to identify patients with SDB at a heart failure clinic.

METHODS

We performed an in-home sleep study on 115 consecutive patients from our heart failure clinic. Clinical characteristics, blood samples, daytime sleepiness and quality of life were registered.

RESULTS

Among 115 patients, 52% had moderate to severe SDB. Body Mass Index (BMI) ≥ 30 kg/m² was the only independent predictor of moderate to severe SDB [Odds ratio (OR) = 3.62, 95% Confidence interval (CI) 1.40-9.36, p = 0.008]. Quality of life and level of sleepiness were not significantly associated with SDB. Patients with mild to moderate chronic obstructive pulmonary disease (COPD) were unlikely to have SDB compared with patients without COPD (OR = 0.10, 95% CI 0.02-0.43, p = 0.002). Hypertension was a predictor of having obstructive sleep apnoea (OR = 2.78, 95% CI 1.15-6.75, p = 0.02), while haemoglobin ≥ 15 g/dl was associated with central sleep apnoea (OR = 6.71, 95% CI 1.96-22.99, p = 0.002).

CONCLUSION

BMI ≥ 30 kg/m(2) is associated with moderate to severe SDB, both obstructive and central sleep apnoea. Thus, BMI may be used as one of the selection criteria for referral of heart failure patients to a sleep specialist.

A novel therapeutic approach for the treatment of central sleep apnea: The remedē® system

Central sleep apnea (CSA) occurs primarily in cardiovascular patients and is associated with high morbidity and mortality. The disorder often is unrecognized due to the overlap of symptoms with those of the underlying cardiac disease. CSA can be easily diagnosed with a sleep study. Following optimization of all co-morbidities, the therapeutic approach available currently focuses on mask-based therapies which suffer from poor patient adherence. A new therapy, the remedē® System, has been developed; it utilizes a transvenous, fully implantable system providing phrenic nerve stimulation intended to restore a more normal breathing pattern. The therapy demonstrated promising results based on an initial chronic study and a randomized trial is underway to further evaluate safety and efficacy of this novel system in patients with CSA.

"I'd eat a bucket of nails if you told me it would help me sleep:" perceptions of insomnia and its treatment in patients with stable heart failure

BACKGROUND

Poor sleep, including insomnia, is common among patients with heart failure (HF). However, little is known about the efficacy of interventions for insomnia in this population. Prior to developing interventions, there is a need for better understanding of patient perceptions about insomnia and its treatment.

OBJECTIVES

To evaluate HF patients' perceptions about 1) insomnia and its consequences; 2) predisposing, precipitating, and perpetuating factors for insomnia; 3) self-management strategies and treatments for insomnia; and 4) preferences for insomnia treatment.

METHODS

The study, guided by the "3 P" model of insomnia, employed a parallel convergent mixed methods design in which we obtained qualitative data through focus groups and quantitative data through questionnaires (sleep quality, insomnia severity, dysfunctional beliefs and attitudes about sleep; sleep-related daytime symptoms and functional performance). Content analysis was used to evaluate themes arising from the focus group data, and descriptive statistics were used to analyze the quantitative data. The results of both forms of data collection were compared and synthesized.

RESULTS

HF patients perceived insomnia as having a negative impact on daytime function and comorbid health problems, pain, nocturia, and psychological factors as perpetuating factors. They viewed use of hypnotic medications as often necessary but disliked negative daytime side effects. They used a variety of strategies to manage their insomnia, but generally did not mention their sleep concerns to physicians whom they perceived as not interested in sleep.

CONCLUSIONS

HF patients believe insomnia is important and multi-factorial. Behavioral treatments, such as cognitive behavioral therapy, for insomnia may be efficacious in modifying perpetuating factors and likely to be acceptable to patients.

The contribution of hypoxia to the association between sleep apnoea, insomnia, and cardiovascular mortality in community-dwelling elderly with and without cardiovascular disease

AIMS

This study explores if nightly hypoxia (i.e. percentage of sleep time with oxygen saturation lower than 90% (SaO2<90%)) contributed to the association between sleep-disordered breathing (SDB) and insomnia in community-dwelling elderly with and without cardiovascular disease (CVD). A second aim was to explore a potential cut-off score for hypoxia to predict insomnia and the association of the cut-off with clinical characteristics and cardiovascular mortality.

METHOD

A total of 331 community-dwelling elderly aged 71-87 years underwent one-night polygraphic recordings. The presence of insomnia was recorded by a self-report questionnaire. The presence of CVD was objectively established and mortality data were collected after three and six years.

RESULTS

In both patients with CVD (n=119) or without CVD (n=212) SDB was associated with hypoxia (p<0.005). Only in the patients with CVD was hypoxia associated with insomnia (p<0.001) which mediated an indirect effect (p<0.05) between SDB and insomnia. Hypoxia of more than 1.5% of sleep time with SaO2<90% was found to be a critical level for causing insomnia. According to this criterion 32% (n=39) and 26% (n=55) of those with and without CVD had hypoxia, respectively. These groups did not differ with respect to age, gender, body mass index, diabetes, hypertension, respiratory disease or levels of SDB. However, in the CVD group, hypoxia was associated with cardiovascular mortality at the three-year follow-up (p=0.008) and higher levels of insomnia (p=0.002).

CONCLUSION

In the elderly with CVD, SDB mediated by hypoxia can be associated with more insomnia and a worse prognosis.

Can cardiorespiratory polygraphy replace portable polysomnography in the assessment of sleep-disordered breathing in heart failure patients?

PURPOSE

Portable polysomnography (PSG) and cardiorespiratory polygraphy are increasingly being used in the assessment of sleep-disordered breathing (SDB) in heart failure patients. Scoring of SDB from cardiorespiratory polygraphy recordings is based only on respiratory signals, while electroencephalographic, electrooculographic and electromyographic channels are taken into account when using PSG recordings. The aim of this study was to assess the agreement between these two scoring methods.

METHODS

An overnight sleep study was performed in 67 heart failure patients using a standard portable polysomnograph. Each recording was scored twice, once using all acquired signals (PSG mode) and, after a median of 64 days, using only respiratory signals (cardiorespiratory mode). Agreement was assessed by Bland-Altman analysis and Cohen's kappa.

RESULTS

We found that (1) more respiratory events were detected using cardiorespiratory analysis [median (25th percentile, 75th percentile), 75 (39, 200) events] compared to analysis of portable PSG [69 (29, 173) events, p < 0.0001], the extra events being, for the vast majority, central in origin; (2) the apnea/hypopnea index (AHI) estimated by cardiorespiratory polygraphy [11.9 (5.7, 30.8)/h] showed a negligible negative bias relative to portable PSG [15.1 (5.7, 33.6)/h; bias, -0.8 (-2.9, 0.4)/h, p = 0.0002]; (3) limits of agreement between the two systems (-6.2/h, 1.7/h) were much smaller than those previously observed between two nights using the same scoring modality; and (4) the kappa coefficient using categorised AHI was 0.89 (95% confidence interval (CI) 0.82, 0.96).

CONCLUSIONS

We found a high degree of agreement between the AHIs obtained from the two scoring methods, thus suggesting that cardiorespiratory polygraphy may be used as an alternative to portable PSG in the assessment of SDB in heart failure patients.

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.