The epidemiological characteristics of sleep disordered breathing in congestive heart failure: A prospective, single centre study in Southeast Asia

BACKGROUND

The presence of sleep-disordered breathing (SDB) in congestive heart failure (CHF) is associated with poor prognosis and is underdiagnosed despite advances in CHF management. The prevalence of SDB in CHF remains understudied in South East Asia.

METHODS

A prospective, observational single-centre study was conducted where 116 consecutive patients in a specialised heart failure clinic underwent level 1, attended polysomnography (PSG).

RESULTS

The prevalence of SDB was 78% using the apnoea-hypopnea index (AHI), AHI ⩾ 5/h threshold, and 59% with the AHI ⩾ 15/h threshold. Obstructive sleep apnoea (OSA) was the predominant type of SDB and was associated with increased body mass index and neck circumference. STOP-BANG was predictive of SDB, especially in men. Central sleep apnoea (CSA) patients had worse sleep indexes and lower awake arterial carbon dioxide. SDB was also homogenously present in preserved ejection fraction (EF) CHF.

CONCLUSION

Most of the CHF patients were found to have SDB with the utility of PSG. Local CHF guidelines should include sleep testing for all patients with CHF.The study is registered on ClinicalTrials.gov (NCT05332223) as 'The Epidemiological Characteristics of SDB in Patients with Reduced or Preserved EF CHF'.

Sleep apnea in patients with exacerbated heart failure and overweight

Sleep disorders are a common concomitant comorbidity in patients with heart failure. The aims of our study are to determine the incidence and phenotypic characteristics of sleep apnea in overweight patients with exacerbated heart failure and to assess the degree of involvement of systolic and diastolic function impairment in the individual group. From 100 screened patients with heart failure in our department from 2015 to 2017, 61 met the inclusion criteria and participated in the study. 82% (n = 50) of the patients had obstructive sleep apnea (OSA), and 18% (n = 11) had central sleep apnea (CSA). The CSA group had a significantly lower left ventricular ejection fraction (LVEF) than the OSA group (EF% 49.6 ± 8.5 vs 41.8 ± 11.4; p = 0.013). A negative correlation was found between LVEF and the number of central apnea events (r = -0.52; p < 0.001). More frequent hospitalizations for heart failure (HF) and higher mortality rate were found in the CSA group. Screening for sleep apnea in patients with exacerbated heart failure and obesity is necessary for the complex treatment of these patients.

Relationships between Heart Chamber Morphology or Function and Respiratory Parameters in Patients with HFrEF and Various Types of Sleep-Disordered Breathing

Sleep-disordered breathing (SDB), i.e., central sleep apnea (CSA) and obstructive sleep apnea (OSA), affects the prognosis of patients with heart failure with reduced ejection fraction (HFrEF). The study assessed the relationships between heart chamber size or function and respiratory parameters in patients with HFrEF and various types of SDB. The 84 participants were patients aged 68.3 ± 8.4 years (80% men) with an average left ventricular ejection fraction (LVEF) of 25.5 ± 6.85% who qualified for cardioverter-defibrillator implantation with or without cardiac resynchronization therapy. SDB, defined by an apnea-hypopnea index (AHI) ≥ five events/hour, was diagnosed in 76 patients (90.5%); SDB was severe in 31 (36.9%), moderate in 26 (31.0%), and mild in 19 (22.6%). CSA was the most common type of SDB (64 patients, 76.2%). A direct proportional relationship existed only in the CSA group between LVEF or stroke volume (SV) and AHI (p = 0.02 and p = 0.07), and between LVEF or SV and the percentage of total sleep time spent with hemoglobin oxygen saturation < 90% (p = 0.06 and p = 0.07). In contrast, the OSA group was the only group in which right ventricle size showed a positive relationship with AHI (for basal linear dimension [RVD1] p = 0.06), mean duration of the respiratory event (for RVD1 p = 0.03, for proximal outflow diameter [RVOT proximal] p = 0.009), and maximum duration of respiratory event (for RVD1 p = 0.049, for RVOT proximal p = 0.006). We concluded that in HFrEF patients, SDB severity is related to LV systolic function and SV only in CSA, whereas RV size correlates primarily with apnea/hypopnea episode duration in OSA.

A State-of-the-Art Review on Sleep Apnea Syndrome and Heart Failure

Heart failure (HF) affects many patients worldwide every year. It represents a leading cause of hospitalization and still, today, mortality remains high, albeit the progress in treatment strategies. Several factors contribute to the development and progression of HF. Among these, sleep apnea syndrome represents a common but still underestimated factor because its prevalence is substantially higher in patients with HF than in the general population and is related to a worse prognosis. This review summarizes the current knowledge about sleep apnea syndrome coexisting with HF in terms of morbidity and mortality to provide actual and future perspectives about the diagnosis, evaluation, and treatment of this association.

Cheyne-stokes respiration in children with heart failure

Cheyne-Stokes respiration (CSA-CSR) is a form of central sleep apnea characterized by alternating periods of hyperventilation and central apneas or hypopneas. CSA-CSR develops following a cardiac insult resulting in a compensatory increase in sympathetic activity, which in susceptible patients causes hyperventilation and destabilizes respiratory control. The physiological changes that occur in CSA-CSR include hyperventilation, a reduced blood gas buffering capacity, and circulatory delay. In adults, 25% to 50% of patients with heart failure are reported to have CSA-CSR. The development of CSA-CSR in this group of patients is considered a poor prognostic sign. The prevalence, progression, and treatment outcomes of CSA-CSR in children remain unclear with only 11 children being described in the literature. The lack of data is possibly not due to the paucity of children with severe heart failure and CSA-CSR but because they may be under-recognized, compounded by the absence of routine polysomnographic assessment of children with moderate to severe heart failure. Building on much broader experience in the diagnosis and management of CSA-CSR in adult sleep medicine and our limited experience in a pediatric quaternary center, this paper will discuss the prevalence of CSA-CSR, its' treatment options, outcomes in children, and the potential future direction for research in this understudied area of pediatric sleep medicine.

DOISNORE50: a perioperative sleep questionnaire predictive of obstructive sleep apnea and postoperative medical emergency team activation. A learning health system approach to sleep questionnaire development and screening

STUDY OBJECTIVES

Patients with obstructive sleep apnea (OSA) have a disproportionate increase in postoperative complications and medical emergency team activation (META). We previously introduced DOISNORE50 (Diseases, Observed apnea, Insomnia, Snoring, Neck circumference > 18 inches, Obesity with BMI > 32, R = are you male, Excessive daytime sleepiness, 50 = age ≥ 50) from sleep questionnaire ISNORED using features associated with increased odds of META in perioperative patients. Performance of DOISNORE50 (DOISNORE) had yet to be tested.

METHODS

The performance of DOISNORE was tested along with questionnaire ISNORED and STOP-BANG questionnaires among 300 out of 392 participants without known OSA referred to the sleep lab. In study 2, the performance of DOISNORE was tested among 64,949 lives screened in perioperative assessment clinic from 2016 to 2020.

RESULTS

Receiver operating characteristic curve demonstrated that best performance was achieved with responses, with area under curve of 0.801. DOISNORE's predictability of OSA risk remained stable from 2018 to 2020 with area under curve of 0.78 and a Cronbach alpha of 0.65. Patients at high risk for OSA (DOISNORE ≥ 6) were associated with an increase of META (odds ratio 1.30, 95% confidence interval 1.12-1.45). Higher relative risk was noted among patients with congestive heart failure and hypercapnia.

CONCLUSIONS

DOISNORE is predictive of OSA and postoperative META. Perioperative strategies against META should consider DOISNORE questionnaire and focused screening among patients with heart failure and hypercapnia.

CITATION

Namen AM, Forest D, Saha AK, et al. DOISNORE50: a perioperative sleep questionnaire predictive of obstructive sleep apnea and postoperative medical emergency team activation. A learning health system approach to sleep questionnaire development and screening. J Clin Sleep Med. 2022;18(8):1909-1919.

Effects of Sacubitril-Valsartan on Clinical, Echocardiographic, and Polygraphic Parameters in Patients Affected by Heart Failure With Reduced Ejection Fraction and Sleep Apnea

Background

Heart failure with reduced ejection fraction (HFrEF) is a clinical condition frequently diagnosed in clinical practice. In patients affected by HFrEF, sleep apnea (SA) can be detected among the most frequent comorbidities. Sacubitril–valsartan (sac/val) association has been proven to be effective in reducing disease progression and all-cause mortality in HFrEF patients. Sac/val treatment can potentially attenuate SA development via several pathophysiologic mechanisms, including improvement of global hemodynamics, reduction of extracellular fluid overload, and decrease of sympathetic neural activity.

Methods

We recruited 132 patients affected by HFrEF and SA, already under treatment with continuous positive airway pressure (CPAP), which was discontinued 24 h before the scheduled study timepoints. Physical examination, echocardiography, nocturnal cardio-respiratory monitoring, and laboratory tests were performed in each patient at baseline and after a 6-month treatment with sac/val.

Results

After 6 months, sac/val induced statistically significant changes in clinical, hemodynamic, biohumoral (NT-proBNP, serum electrolytes, creatinine, and uric acid), and echocardiographic parameters. In particular, cardiac index (CI), both atrial and ventricular volumes and global longitudinal strain (GLS) improved. Moreover, polysomnography, carried out during a temporary CPAP interruption, revealed a significant reduction in global apnea-hypopnea index (AHI) value (p < 0.0001), central AHI (p < 0.0001), obstructive AHI (p < 0.0001), oxygen desaturation index (ODI) (p < 0.0001), and percentage time of saturation below 90% (TC90) (p < 0.0001). The changes of CI, estimated glomerular filtration rate (eGFR), NT-proBNP, and tricuspid annular plane excursion (TAPSE) contributed to 23.6, 7.6, 7.3, and 4.8% of AHI variability, respectively, and the whole model accounted for a 43.3% of AHI variation.

Conclusions

Our results suggest that treatment with sac/val is able to significantly improve the cardiorespiratory performance of patients with HFrEF and SA, integrating the positive impact of CPAP. Thus, both CPAP and sac/val therapy may synergistically contribute to lower the risks of both cardiac and pulmonary complications in HFrEF patients with SA.

Management of Obstructive Sleep Apnea in Patients With Heart Failure

Sleep apnea is traditionally classified as obstructive sleep apnea (OSA), which occurs when the upper airway collapses due to the relaxation of oropharyngeal musculature, and central sleep apnea occurs when the brainstem cannot stimulate breathing. Most sleep apnea in patients with heart failure (HF) results from coexisting OSA and central sleep apnea (CSA), or complex sleep apnea syndrome. OSA and CSA are common in HF and can be involved in its progression by exposure to the heart to intermittent hypoxia, increased preload and afterload, activating sympathetic, and decreased vascular endothelial function. A majority of treatments have been investigated in patients with CSA and HF; however, less or short-term randomized trials demonstrated whether treating OSA in patients with HF could improve morbidity and mortality. OSA could directly influence the patient's recovery. This review will focus on past and present studies on the various therapies for OSA in patients with HF and summarize CSA treatment options for reasons of reference and completeness. More specifically, the treatment covered include surgical and non-surgical treatments and reported the positive and negative consequences for these treatment options, highlighting possible implications for clinical practice and future research directions.

Prognostic Impact of Sleep Patterns and Related-Drugs in Patients with Heart Failure

Sleep disturbances are frequent among patients with heart failure (HF). We hypothesized that self-reported sleep disturbances are associated with a poor prognosis in patients with HF. A longitudinal study of 119 patients with HF was carried out to assess the association between sleep disturbances and the occurrence of major cardiovascular events (MACE). All patients with HF completed self-administered questionnaires on sleepiness, fatigue, insomnia, quality of sleep, sleep patterns, anxiety and depressive symptoms, and central nervous system (CNS) drugs intake. Patients were followed for a median of 888 days. Cox models were used to estimate the risk of MACE associated with baseline sleep characteristics. After adjustment for age, the risk of a future MACE increased with CNS drugs intake, sleep quality and insomnia scores as well with increased sleep latency, decreased sleep efficiency and total sleep time. However, after adjustment for left ventricular ejection fraction and hypercholesterolemia the HR failed to be significant except for CNS drugs and total sleep time. CNS drugs intake and decreased total sleep time were independently associated with an increased risk of MACE in patients with HF. Routine assessment of self-reported sleep disturbances should be considered to prevent the natural progression of HF.

Clinical Characteristics and In-Hospital Outcome of Acute Heart Failure Patients Admitted to the Medical Ward of University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Background

Despite the growing burden of heart failure in developing countries, data describing the clinical characteristics and in-hospital outcomes of acute heart failures are limited. Therefore, this study aimed at describing the clinical characteristics and in-hospital outcomes of acute heart failure patients admitted to the medical ward of University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia.

Methods

A prospective observational hospital-based cross-sectional study was conducted on 226 patients with acute heart failure at the University of Gondar Comprehensive Specialized Hospital from November 2019 to October 2020. Data were collected by using a pretested data abstraction format and analyzed with Statistical Package for Social Sciences version 21. Bivariable and multivariable binary logistic regression model were fitted to identify factors associated with in-hospital outcome and reported with 95% confidence interval (CI). P-value <0.05 was considered as statistically significant.

Results

The mean (± standard deviation) age of the study participant was 51.17±19.03 years and 59.3% were females. Majority, 60.6% of patients were admitted with new onset heart failure. Dyspnea (88.05%) and peripheral edema (80.5%) were the most frequent clinical findings. The in-hospital mortality was 10.6% (95% CI: 7.1–14.7). Atrial fibrillation (AOR=9.46; 95% CI: 1.49–60.29), concurrent ischemic heart disease (AOR=8.23; 95% CI: 1.15–58.89), being admitted with reduced left ventricular ejection fraction (AOR=5.36; 95% CI: 2.81–35.52), presence of orthopnea (AOR=6.63; 95% CI: 2.94–46.76), and using intranasal oxygen therapy (AOR=9.41; 95% CI: 1.35–65.82) were significantly associated with in-hospital mortality in patients with acute heart failure.

Conclusion

The in-hospital mortality of acute heart failure patients was relatively higher in the study area. Therefore, specific preventative and therapeutic strategies focusing on heart failure patients with reduced left ventricular ejection fraction, atrial fibrillation, ischemic heart disease, orthopnea, and intranasal oxygen therapy are required to reduce the mortality rate.

Sleep Disordered Breathing and Cardiovascular Disease: JACC State-of-the-Art Review

Sleep disordered breathing causes repetitive episodes of nocturnal hypoxemia, sympathetic nervous activation, and cortical arousal, often associated with excessive daytime sleepiness. Sleep disordered breathing is common in people with, or at risk of, cardiovascular (CV) disease including those who are obese or have hypertension, coronary disease, heart failure, or atrial fibrillation. Current therapy of obstructive sleep apnea includes weight loss (if obese), exercise, and positive airway pressure (PAP) therapy. This improves daytime sleepiness. Obstructive sleep apnea is associated with increased CV risk, but treatment with PAP in randomized trials has not been shown to improve CV outcome. Central sleep apnea (CSA) is not usually associated with daytime sleepiness in heart failure or atrial fibrillation and is a marker of increased CV risk, but PAP has been shown to be harmful in 1 randomized trial. The benefits of better phenotyping, targeting of higher-risk patients, and a more personalized approach to therapy are being explored in ongoing trials.

Diagnosis and management of heart failure from hospital admission to discharge: A practical expert guidance

Heart failure (HF) has high event rates, mortality, and is challenging to manage in clinical practice. Clinical management is complicated by complex therapeutic strategies in a population with a high prevalence of comorbidity and general frailty. In the last four years, an abundance of research has become available to support multidisciplinary management of heart failure from within the hospital through to discharge and primary care as well as supporting diagnosis and comorbidity management. Within the hospital setting, recent evidence supports sacubitril-valsartan combination in frail, deteriorating or de novo patients with LVEF≤40%. Furthermore, new strategies such as SGLT2 inhibitors and vericiguat provide further benefit for patients with decompensating HF. Studies with tafamidis report major clinical benefits specifically for patients with ATTR cardiac amyloidosis, a remaining underdiagnosed and undertreated disease. New evidence for medical interventions supports his bundle pacing to reduce QRS width and improve haemodynamics as well as ICD defibrillation for non-ischemic cardiomyopathy. The Mitraclip reduces hospitalisations and mortality in patients with symptomatic, secondary mitral regurgitation and ablation reduces mortality and hospitalisations in patients with paroxysmal and persistent atrial fibrillation. In end-stage HF, the 2018 French Heart Allocation policy should improve access to heart transplants for stable, ambulatory patients and, mechanical circulatory support should be considered to avoid deteriorating on the waiting list. In the community, new evidence supports that improving discharge education, treatment and patient support improves outcomes. The authors believe that this review fills the gap between the guidelines and clinical practice and provides practical recommendations to improve HF management.

Adaptive servo ventilation for sleep apnoea in heart failure: the FACE study 3-month data

Rationale

Adaptive servo ventilation (ASV) is contraindicated in patients with systolic heart failure (HF) who have a left ventricular ejection fraction (LVEF) below 45% and predominant central sleep apnoea (CSA). However, the effects of ASV in other HF subgroups have not been clearly defined.

Objective

The European, multicentre, prospective, observational cohort trial, FACE, evaluated the effects of ASV therapy on morbidity and mortality in patients with HF with sleep-disordered breathing (SDB); 3-month outcomes in patient subgroups defined using latent class analysis (LCA) are presented.

Methods

Consecutive patients with HF with predominant CSA (±obstructive sleep apnoea) indicated for ASV were included from 2009 to 2018; the non-ASV group included patients who refused/were noncompliant with ASV. The primary endpoint was time to composite first event (all-cause death, lifesaving cardiovascular intervention or unplanned hospitalisation for worsening of chronic HF).

Measurements and main results

Baseline assessments were performed in 503 patients, and 482 underwent 3-month follow-up. LCA identified six discrete patient clusters characterised by variations in LVEF, SDB type, age, comorbidities and ASV acceptance. The 3- month rate of primary outcome events was significantly higher in cluster 1 patients (predominantly men, low LVEF, severe HF, CSA; 13.9% vs 1.5%–5% in other clusters, p<0.01).

Conclusion

For the first time, our data identified homogeneous patient clusters representing clinically relevant subgroups relating to SDB management in patients with HF with different ASV usage, each with a different prognosis. This may improve patient phenotyping in clinical practice and allow individualisation of therapy.

Sacubitril-valsartan initiation in chronic heart failure patients impacts sleep apnea: the ENTRESTO-SAS study

Aims

Optimizing medical cardiac treatment for sleep apnoea (SA) in patients with chronic heart failure and reduced ejection fraction (HFrEF) is an expert Grade C recommendation based on six studies encompassing a total of 67 patients only. Whether sacubitril–valsartan (SV), a cornerstone of HFrEF medical treatment, impacts SA is unknown and requires evaluation.

Methods and results

The ENTRESTO‐SAS trial is a six‐centre, prospective, open‐label real‐life cohort study (NCT02916160). Ambulatory patients eligible for SV (i.e. HFrEF adults who remain symptomatic despite optimal treatment) were evaluated before and after 3 months of SV (including nocturnal ventilatory polygraphy); 118 patients were final analysed [median age was 66 (IQ_25–75: 56–73) years, 81.4% male, 36.5% New York Heart Association III–IV, N‐terminal pro‐B‐type natriuretic peptide level of 1564 (701–3376) ng/L, left ventricular ejection fraction of 30 (25–34)%, 60.7% ischaemic HFrEF, 97.5% initially treated with angiotensin‐converting enzyme inhibitors or angiotensin II receptor blockers, 83.9% with beta‐blockers, 64.4% with mineralocorticoid receptor antagonists, and 74.6% with diuretics]. Three groups were defined according to initial central/obstructive apnoea–hypopnoea indices (AHIs): G1 (n = 49, AHI_central ≥ 5/h and AHI_obstructive < 15/h); G2 (n = 27, AHI_obstructive ≥ 15/h); and G3 (n = 42, AHI_central < 5/h and AHI_obstructive < 15/h). At 3 months, the AHI (main predefined outcome) decreased significantly by −7.10/h (IQ_25–75: −16.10 to 0.40; P < 0.001) in G1 + G2 without positive airway pressure treatment (45 patients, median initial AHI of 24.20 (IQ_25–75: 16.40–43.50)/h). Of these, 24.4% presented an AHI decrease ≥50% and 37.78% had a final AHI < 15/h (tendency for improvement from an initial value of 20%: P = 0.0574). For G1 patients (n = 37), AHI significantly decreased from a median of 22.90 (16.00–43.50)/h to 19.20 (12.70–31.10)/h (P = 0.002). For G2 patients (n = 8), AHI decreased from a median of 30.10 (26.40–47.60)/h to 22.75 (14.60–36.90)/h (statistically non‐significant, P = 0.059).

Conclusions

In this real‐life population, SV treatment for 3 months in SA patients is associated with a significant decrease in AHI. These results support the current guidelines that recommend first an optimization of the HFrEF treatment in patients with HFrEF and central SA. A potential positive airway pressure sparing effect merits further investigation.

Obstructive sleep apnea versus central sleep apnea: prognosis in systolic heart failure

Background

In chronic heart failure (CHF), obstructive sleep apnea (OSA) and Cheyne-Stokes respiration (CSR) are associated with increased mortality. The present study aimed to evaluate the prognostic effect of CSR compared to OSA, in otherwise similar groups of CHF patients.

Methods

Screening for sleep-disordered breathing (SDB) was conducted among patients with CHF of New York Heart Association (NYHA) class II-IV, and left ventricular ejection fraction (LVEF) of ≤45%. The study included 43 patients (4 women) with >25% CSR during sleeping time, and 19 patients (2 women) with OSA and an apnea-hypopnea index (AHI) of ≥6. Patients were followed for a median of 1,371 days. The primary endpoint was mortality, and the secondary endpoint was combined mortality and hospital admissions.

Results

Baseline parameters did not significantly differ between groups, but CSR patients were older and had higher AHI values than OSA patients. Five OSA patients (26%) died, and 14 (74%) met the combined end-point of death or hospitalization. CSR patients had significantly higher risk for both end-points, with 23 (53%) deaths [log-rank P=0.040; HR, 2.70 (1.01-7.22); P=0.047] and 40 (93%) deaths or readmissions [log-rank P=0.029; HR, 1.96 (1.06-3.63); P=0.032]. After adjustment for confounding risk factors, the association between CSR and death remained significant [HR, 4.73 (1.10-20.28); P=0.037], hospital admission rates were not significantly different.

Conclusions

Among patients with CHF, CSR was associated with higher mortality than OSA independently of age and cardiac systolic function. CSR was also an age-independent predictor of unfavorable outcome, but hospital admission rates were not significantly different between the two groups after adjustment.

Cohort profile: FACE, prospective follow-up of chronic heart failure patients with sleep-disordered breathing indicated for adaptive servo ventilation

PURPOSE

FACE is a prospective cohort study designed to assess the effect of adding adaptive servoventilation (ASV) to standard care on morbidity and mortality in patients with chronic heart failure (HF) with preserved (HFpEF), mid-range (HFmrEF) or reduced ejection fraction (HFrEF) who have sleep-disordered breathing (SDB) with an indication for ASV. We describe the study design, ongoing data collection and baseline participant characteristics.

PARTICIPANTS

Consecutive patients with HFpEF, HFmrEF or HFrEF plus SDB with central sleep apnoea (CSA) and indication for ASV were enrolled in the study cohort between November 2009 and December 2018; the ASV group includes those treated with ASV and the control group consists of patients who refused ASV or stopped treatment early. Follow-up is based on standard clinical practice, with visits at inclusion, after 3, 12 and 24 months of follow-up. Primary endpoint is the time to first event: all-cause death or unplanned hospitalisation (or unplanned prolongation of a planned hospitalisation) for worsening of HF, cardiovascular death or unplanned hospitalisation for worsening of HF, and all-cause death or all-cause unplanned hospitalisation.

FINDINGS TO DATE

503 patients have been enrolled, mean age of 72 years, 88% male, 31% with HFrEF. HF was commonly of ischaemic origin, and the number of comorbidities was high. SDB was severe (median Apnoea-Hypopnoea Index 42/hour), and CSA was the main indication for ASV (69%). HF was highly symptomatic; most patients were in NYHA class II (38%) or III (29%).

FUTURE PLANS

Patient follow-up is ongoing. Given the heterogeneous nature of the enrolled population, a decision was made to use latent class analysis to define homogeneous patient subgroups, and then evaluate outcomes by cluster, and in the ASV and control groups (overall and within patient clusters). First analysis will be performed after 3 months, a second analysis at the 2-year follow-up.

TRIAL REGISTRATION NUMBER

NCT01831128; Pre-results.

Sleep Apnea and Cardiovascular Disease: An Enigmatic Risk Factor

Synchronization of molecular, metabolic, and cardiovascular circadian oscillations is fundamental to human health. Sleep-disordered breathing, which disrupts such temporal congruence, elicits hemodynamic, autonomic, chemical, and inflammatory disturbances with acute and long-term consequences for heart, brain, and circulatory and metabolic function. Sleep apnea afflicts a substantial proportion of adult men and women but is more prevalent in those with established cardiovascular diseases and especially fluid-retaining states. Despite the experimental, epidemiological, observational, and interventional evidence assembled in support of these concepts, this substantial body of work has had relatively modest pragmatic impact, thus far, on the discipline of cardiology. Contemporary estimates of cardiovascular risk still are derived typically from data acquired during wakefulness. The impact of sleep-related breathing disorders rarely is entered into such calculations or integrated into diagnostic disease-specific algorithms or therapeutic recommendations. Reasons for this include absence of apnea-related symptoms in most with cardiovascular disease, impediments to efficient diagnosis at the population level, debate as to target, suboptimal therapies, difficulties mounting large randomized trials of sleep-specific interventions, and the challenging results of those few prospective cardiovascular outcome trials that have been completed and reported. The objectives of this review are to delineate the bidirectional interrelationship between sleep-disordered breathing and cardiovascular disease, consider the findings and implications of observational and randomized trials of treatment, frame the current state of clinical equipoise, identify principal current controversies and potential paths to their resolution, and anticipate future directions.

Central and Obstructive Apneas in Heart Failure With Reduced, Mid-Range and Preserved Ejection Fraction

Background: Although central apneas (CA) and obstructive apneas (OA) are highly prevalent in heart failure (HF), a comparison of apnea prevalence, predictors and clinical correlates in the whole HF spectrum, including HF with reduced ejection fraction (HFrEF), mid-range EF (HFmrEF) and preserved EF (HFpEF) has never been carried out so far.

Materials and methods: 700 HF patients were prospectively enrolled and then divided according to left ventricular EF (408 HFrEF, 117 HFmrEF, 175 HFpEF). All patients underwent a thorough evaluation including: 2D echocardiography; 24-h Holter-ECG monitoring; cardiopulmonary exercise testing; neuro-hormonal assessment and 24-h cardiorespiratory monitoring.

Results: In the whole population, prevalence of normal breathing (NB), CA and OA at daytime was 40, 51, and 9%, respectively, while at nighttime 15, 55, and 30%, respectively. When stratified according to left ventricular EF, CA prevalence decreased (daytime: 57 vs. 43 vs. 42%, p = 0.001; nighttime: 66 vs. 48 vs. 34%, p < 0.0001) from HFrEF to HFmrEF and HFpEF, while OA prevalence increased (daytime: 5 vs. 8 vs. 18%, p < 0.0001; nighttime 20 vs. 29 vs. 53%, p < 0.0001).

In HFrEF, male gender and body mass index (BMI) were independent predictors of both CA and OA at nighttime, while age, New York Heart Association functional class and diastolic dysfunction of daytime CA. In HFmrEF and HFpEF male gender and systolic pulmonary artery pressure were independent predictors of CA at daytime, while hypertension predicted nighttime OA in HFpEF patients; no predictor of nighttime CA was identified. When compared to patients with NB, those with CA had higher neuro-hormonal activation in all HF subgroups. Moreover, in the HFrEF subgroup, patients with CA were older, more comorbid and with greater hemodynamic impairment while, in the HFmrEF and HFpEF subgroups, they had higher left atrial volumes and more severe diastolic dysfunction, respectively. When compared to patients with NB, those with OA were older and more comorbid independently from background EF.

Conclusions: Across the whole spectrum of HF, CA prevalence increases and OA decreases as left ventricular systolic dysfunction progresses. Different predictors and specific clinical characteristics might help to identify patients at risk of developing CA or OA in different HF phenotypes.

Preoperative Sleep Questionnaires Identify Medical Emergency Team Activation in Older Adults

Patients with obstructive sleep apnea (OSA) have increased postoperative complications that are important for patient safety and healthcare utilization. Questionnaires help identify patients at risk for OSA; however, among older adults who preoperatively self-administered OSA questionnaires, the frequency of postoperative Medical Emergency Team Activation (META), rapid response, code blue, code stroke, is unknown.

OBJECTIVES

Identify whether having OSA questionnaires completed by patients is feasible in the preoperative clinic. Determine the frequency of META among older patients at risk for OSA.

DESIGN AND INTERVENTION

Cohort of prospective patients independently completed 2 OSA questionnaires in a preoperative clinic, STOP-Bang (SB) and ISNORED (IS). Observers blinded to questionnaire responses recorded incidence of META.

SETTING AND PARTICIPANTS

Of the 898 consecutive patients approached in the preoperative assessment clinic and surgical navigation center, 575 (64%) consented and completed the questionnaires in <5 minutes and were included in the analysis.

MEASURES

Sleep questionnaire responses and frequency of inpatient postoperative META.

RESULTS

With an affirmative response to ≥3 questions on either questionnaire, 65% of patients enrolled were at risk for OSA. Of these, 3.1% sustained an META. In patients at risk for OSA, META occurred in 7.6% (SB+) and 7.2% (IS+) vs 2.5% (SB+) and 1.7% (IS+) for low risk. METAs were disproportionately higher among patients aged ≥65 years (6.3% vs 1.7%; P < .018), American Society of Anesthesiologists (ASA) physical status class ≥3, and IS+. All patients with META positively answered ≥3 of 15 components of the 2 questionnaires.

CONCLUSIONS/IMPLICATIONS

Preoperative, self-administration of SB and IS questionnaires is feasible. Overall, 65% of those with affirmative responses to ≥3 questions were at risk for OSA and associated with a disproportionate number of postoperative META in older patients. Additionally, risk of OSA identified by preoperative sleep questionnaires was associated with postoperative META among older adults. Use of clinical tools and OSA questionnaires may improve preoperative identification of META 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.

Effects of Adaptive Servoventilation Therapy for Central Sleep Apnea on Health Care Utilization and Mortality: A Population-Based Study

STUDY OBJECTIVES

Adaptive servoventilation (ASV) is the suggested treatment for many forms of central sleep apnea (CSA). We aimed to evaluate the impact of treating CSA with ASV on health care utilization.

METHODS

In this population-based study using the Rochester Epidemiology Project database, we identified patients over a 9-year period who were diagnosed with CSA (n = 1,237), commenced ASV therapy, and had ≥ 1 month of clinical data before and after ASV initiation. The rates of hospitalizations, emergency department visits (EDV), outpatient visits (OPV) and medications prescribed per year (mean ± standard deviation) in the 2 years pre-ASV and post-ASV initiation were compared.

RESULTS

We found 309 patients (68.0 ± 14.6 years, 80.3% male, apnea-hypopnea index 41.6 ± 26.5 events/h, 78% with cardiovascular comorbidities, 34% with heart failure) who met inclusion criteria; 65% used ASV ≥ 4 h/night on ≥ 70% nights in their first month. The overall 2-year mortality rate was 9.4% and CSA secondary to cardiac cause was a significant risk factor for mortality (hazard ratio 1.81, 95% CI 1.09-3.01, P = .02). Comparing pre-ASV and post-ASV initiation, there was no change in the rate of hospitalization (0.72 ± 1.63 versus 0.79 ± 1.44, P = .46), EDV (1.19 ± 2.18 versus 1.26 ± 2.08, P = .54), OPV (31.59 ± 112.42 versus 13.60 ± 17.36, P = .22), or number of prescribed medications (6.68 ± 2.0 versus 5.31 ± 5.86, P = .06). No differences in these outcomes emerged after accounting for adherence to ASV, CSA subtype and comorbidities via multiple regression analysis (all P > .05).

CONCLUSIONS

Our cohort of patients with CSA was quite ill and the use of ASV was not associated with a change in health care utilization.

Evaluation of Early Left Ventricular Dysfunction in Patients with Duchenne Muscular Dystrophy Using Two-Dimensional Speckle Tracking Echocardiography and Tissue Doppler Imaging

Although progressive cardiac dysfunction is the leading cause of death in patients with Duchenne muscular dystrophy (DMD), their cardiac function measured by conventional echocardiography has been generally interpreted as normal at a young age. We aimed to determine whether two-dimensional speckle tracking echocardiography (STE) or tissue Doppler imaging (TDI) could be used for early identification and detection of cardiac dysfunction in young patients with DMD. Thirteen pediatric patients (mean age, 9.69 ± 2.2 years) with DMD and 26 age-matched healthy children (mean age, 9.65 ± 2.2 years) were included in the study. All patients were examined via conventional echocardiography, TDI, and STE. Standard echocardiographic measurements of left ventricular (LV) systolic and diastolic function were obtained. Myocardial velocities including peak-systolic and early- and late-diastolic myocardial velocities were calculated in longitudinal direction in the interventricular septum, using TDI. Speckle tracking analyses were performed by acquiring apical four-, three-, and two-chamber views with the highest possible frame rates. Conventional parameters were similar between the two groups, but heart rates were higher in patients with DMD than in controls. The results of LV diastolic function evaluated using TDI showed that annular peak velocity during early diastole (e'; 10.9 ± 1.7 vs. 14.6 ± 1.7 cm/s), e'/a' ratio (2.0 ± 0.5 vs. 3.0 ± 0.5), E/e' ratio (9.4 ± 1.4 vs. 7.3 ± 0.8), and myocardial performance index (0.46 ± 0.05 vs. 0.36 ± 0.06) of the mitral septal annulus among patients with DMD differed significantly from those of healthy children. A significant decrease in global longitudinal systolic strain was found in patients with DMD (- 16.6 ± 3.7 vs. - 21.2 ± 2.1), with a marked decrease in the LV basal inferolateral and basal inferior walls. In young patients with DMD who have global normal systolic function, reductions in systolic deformation parameters as well as reduced early diastolic myocardial velocities can be detected particularly in the basal inferolateral LV walls. The prognostic significance of these findings warrants further longitudinal follow-up.

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.

Clinical Significance of Get With the Guidelines-Heart Failure Risk Score in Patients With Chronic Heart Failure After Hospitalization

Background The Get With the Guidelines-Heart Failure ( GWTG - HF ) risk score was developed using American Heart Association GWTG - HF program data and predicts in-hospital mortality in patients with acute heart failure (HF). We aimed to clarify the prognostic impacts of the GWTG - HF risk score in patients with HF after discharge. Methods and Results We examined the GWTG - HF score in 1452 patients with HF, who were admitted to our hospital and discharged after treatment, by calculating 7 predetermined variables. We divided all subjects into 3 groups according to the GWTG - HF risk score (low, moderate, and high score groups). The plasma B-type natriuretic peptide level significantly increased with increasing GWTG - HF risk score severity (median values of B-type natriuretic peptide: 167.0 in low, 260.7 in moderate, and 418.2 pg/mL in high score groups). We followed up all subjects after discharge, and there were 347 (23.9%) all-cause deaths and 407 (28.0%) cardiac events in follow-up periods. A Kaplan-Meier survival curve demonstrated that event rates of all-cause death and cardiovascular events, including worsening HF and cardiac death, significantly increased with increasing GWTG - HF risk score severity in all subjects, and also in 749 patients with HF with preserved ejection fraction (ejection fraction ≥50%) and 703 patients with HF with reduced ejection fraction (ejection fraction <50%) patients. The multivariable Cox proportional hazard regression analysis demonstrated that the GWTG - HF risk score was one of the significant predictors of all-cause mortality and cardiac events (all-cause mortality: hazard ratio, 1.537, 95% confidence interval, 1.172-2.023; cardiac events: hazard ratio, 1.584, 95% confidence interval, 1.344-1.860, per 10-point increase of GWTG - HF score). Conclusions The GWTG - HF risk score is a useful multivariable score model for several years after hospitalization in patients with HF in a Japanese population.

Management of Sleep Apnea in Heart Failure

Sleep-disordered breathing (SDB) is highly prevalent in heart failure (HF). The presence of SDB in patients with HF appears to be associated with increased risk of cardiovascular morbidity and mortality. In this article, we describe the types, pathophysiology, and consequences of SDB and discuss ways in which SDB can be diagnosed. We also lay emphasis on the recent randomized controlled trials that have had a major impact on how SDB is managed and highlight the complex relationship between SDB and outcomes.

Obstructive Sleep Apnea in Heart Failure: Review of Prevalence, Treatment with Continuous Positive Airway Pressure, and Prognosis

Obstructive sleep apnea is a sleep-related breathing disorder that has a major impact on cardiovascular function. It has been associated with hypertension, coronary artery disease, cardiac arrhythmias, sudden cardiac death, and heart failure. This review focuses on the relationship between obstructive sleep apnea and heart failure with either reduced or preserved ejection fraction. We discuss the pathophysiology of obstructive sleep apnea, as well as its prevalence, treatment outcomes with continuous positive airway pressure, and prognosis in these 2 distinct types of heart failure. We also identify areas in which further work is needed to improve our understanding of this association in heart failure patients.

Adaptive servo-ventilation to treat central sleep apnea in heart failure with reduced ejection fraction: the Bad Oeynhausen prospective ASV registry

BACKGROUND

Central sleep apnea (CSA) is highly prevalent in heart failure patients with reduced left ventricular ejection fraction (HF-REF). The Bad Oeynhausen Adaptive Servo-ventilation (ASV) registry (NCT01657188) was designed to investigate whether treatment of CSA with ASV improved survival in HF-REF patients; the effects of ASV on symptoms and cardiopulmonary performance were also investigated.

METHODS AND RESULTS

From January 2004 to October 2013, the registry prospectively enrolled HF-REF patients [NYHA class ≥ II, left ventricular ejection fraction (LVEF) ≤ 45%] with moderate to severe predominant CSA [apnea-hypopnea index (AHI) ≥ 15/h]. ASV-treated patients were followed up at 3, 6, 12 and 24 months, including natriuretic peptide concentrations, blood gas analyses, echocardiography, 6-min walk distance (6MWD), and cardiopulmonary exercise (CPX) testing. 550 patients were included [age 67.7 ± 10 years, 90% male, 52% in NYHA class ≥ III, LVEF 29.9 ± 8%, AHI 35.4 ± 13.6/h, and time with nocturnal oxygen saturation < 90% (T < 90%) 58 ± 73 min]; ASV was prescribed to 224 patients. Over a median follow-up of 6.6 years, 109 (48.7%) ASV-treated patients and 191 (58.6%) controls died (adjusted Cox modelling hazard ratio of 0.95, 95% confidence interval 0.68-1.24; p = 0.740); older age, lower LVEF, impaired renal function, low sodium concentration, and nocturnal hypoxemia were significant predictors of mortality. Patient reported NYHA functional class improved in the ASV group, but LVEF, CPX, 6MWD, natriuretic peptides and blood gases remained unchanged.

CONCLUSIONS

Long-term ASV treatment of predominant CSA in HF-REF patients included in our registry had no statistically significant effect on survival. ASV improved HF symptoms, but had no significant effects on exercise capacity, LVEF, natriuretic peptide concentrations or blood gases during follow-up as compared to control patients.

Management of Sleep Disordered Breathing in Patients with Heart Failure

PURPOSE OF REVIEW

This paper reviews treatment options for sleep disordered breathing (SDB) in patients with heart failure. We sought to identify therapies for SDB with the best evidence for long-term use in patients with heart failure and to minimize uncertainties in clinical practice by examining frequently discussed questions: what is the role of continuous positive airway pressure (CPAP) in patients with heart failure? Is adaptive servo-ventilation (ASV) safe in patients with heart failure? To what extent is SDB a modifiable risk factor?

RECENT FINDINGS

Consistent evidence has demonstrated that the development of SDB in patients with heart failure is a poor prognostic indicator and a risk factor for cardiovascular mortality. However, despite numerous available interventions for obstructive sleep apnea and central sleep apnea, it remains unclear what effect these therapies have on patients with heart failure. To date, all major randomized clinical trials have failed to demonstrate a survival benefit with SDB therapy and one major study investigating the use of adaptive servo-ventilation demonstrated harm. Significant questions persist regarding the management of SDB in patients with heart failure. Until appropriately powered trials identify a treatment modality that increases cardiovascular survival in patients with SDB and heart failure, a patient's heart failure management should remain the priority of medical care.

Association between sleep-disordered breathing and arterial stiffness in heart failure patients with reduced or preserved ejection fraction

AIMS

Sleep-disordered breathing (SDB) is associated with arterial stiffness, which may be one of the factors that lead to heart failure (HF). We examined the relationship between pulse wave velocity (PWV) and SDB in patients who have HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF).

METHODS AND RESULTS

We measured the apnoea-hypopnoea index (AHI) by polysomnography, echocardiographic parameters, and PWV in 221 HF patients. Age, blood pressure, and PWV were higher in HFpEF (ejection fraction > 50%, n = 70) patients than in HFrEF (ejection fraction < 50%, n = 151) patients. All HF patients were divided into three groups according to AHI: none-to-mild SDB group (AHI < 15 times/h, n = 77), moderate SDB group (15 < AHI < 30 times/h, n = 59), and severe SDB group (AHI > 30 times/h, n = 85). Although blood pressure and echocardiographic parameters did not differ among the three groups, PWV was significantly higher in the severe SDB group than in the none-to-mild and moderate SDB groups (P = 0.002). When the HFrEF and HFpEF patients were analysed separately, PWV was significantly higher in the severe SDB group than in the none-to-mild and moderate SDB groups in patients with HFpEF (P = 0.002), but not in those with HFrEF (P = 0.068). In the multiple regression analysis to determine PWV, the presence of severe SDB was found to be an independent predictor of high PWV in HFpEF (β = 0.234, P = 0.005), but not in HFrEF patients.

CONCLUSIONS

Severe SDB is associated with elevated arterial stiffness and may be related to the pathophysiology of HF, especially in HFpEF patients.

Development of a Sleep Telementorship Program for Rural Department of Veterans Affairs Primary Care Providers: Sleep Veterans Affairs Extension for Community Healthcare Outcomes

RATIONALE

Primary care providers (PCPs) frequently encounter sleep complaints, especially in regions with limited specialty care access.

OBJECTIVES

The U.S. Department of Veterans Affairs Extension for Community Healthcare Outcomes (VA-ECHO) program (based on Project ECHO) has successfully provided rural PCP education in subspecialty areas, including hepatitis C. We describe the feasibility of an ECHO program for sleep medicine.

METHODS

ECHO creates a virtual learning community through video-teleconferencing, combining didactics with individualized clinical case review. We invited multidisciplinary providers to attend up to 10 stand-alone, 1-hour sessions. Invitees completed a needs assessment, which guided curriculum development. After program completion, we examined participant characteristics and self-reported changes in practice and comfort with managing sleep complaints. We surveyed participation barriers among invitees with low/no attendance.

MEASUREMENTS AND MAIN RESULTS

Of the 39 program participants, 38% worked in rural healthcare. Participants included nurse practitioners (26%), registered nurses (21%), and physicians (15%). Seventeen (44%) completed the summative program evaluation. Respondents anticipated practice change from the program, especially in patient education about sleep disorders (93% of respondents). Respondents reported improved comfort managing sleep complaints, especially sleep-disordered breathing, insomnia, and sleep in post-traumatic stress disorder (80% of respondents each). A follow-up survey of program invitees who attended zero to two sessions reported scheduling conflicts (62%) and lack of protected time (52%) as major participation barriers.

CONCLUSIONS

Participants in a pilot sleep medicine VA-ECHO program report practice change and increased comfort managing common sleep complaints. Future work is needed to identify objective measures of return on investment and address participation barriers.

Recognition of Sleep Apnea Is Increasing. Analysis of Trends in Two Large, Representative Databases of Outpatient Practice

RATIONALE

Little is known about recent trends in physician reporting of sleep apnea during outpatient practice visits.

OBJECTIVES

To assess trends in the frequency of adult outpatient visits for sleep apnea in the United States, the clinicians who provided those visits, and the characteristics of patients reported to have sleep apnea; and to assess whether the reporting of a diagnosis of sleep apnea varies across regions of the country as a function of body weight and insurance status.

METHODS

We reviewed annual stratified samples of patients identified as having sleep apnea during physician office visits in the U.S. National Ambulatory Medical Care Survey database, and during visits to hospital outpatient practices in the U.S. National Hospital Ambulatory Medical Care Survey database, between 1993 and 2010. The aggregate data set included records of 838,000 ambulatory practice visits.

MEASUREMENTS AND MAIN RESULTS

During this 17-year period, survey reports of a diagnosis of sleep apnea increased 14.6- fold, from 420,000 to 6.37 million per year (P = 0.0002). Thirty-three percent were reported by primary care providers, 17% by pulmonologists, and 10% by otolaryngologists. Over the period of observation, reports of a diagnosis of sleep apnea by "other groups" increased considerably (P < 0.001). The per capita rate of sleep apnea diagnoses per 1,000 persons per year differed across regions of the United States (P < 0.0001). Regions that reported a higher rate of sleep apnea appeared to be influenced by obesity (P < 0.001) and health insurance status (P < 0.005).

CONCLUSIONS

Diagnoses of sleep apnea during outpatient visits to hospital-based and non-hospital-based practices in the United States were much more frequent in 2010 than in 1993, as reported by outpatient practice clinicians participating in national surveys. Although the majority of diagnoses of sleep apnea were reported by primary care providers, pulmonologists, and otolaryngologists (60%), there was a substantial increase in reports of sleep apnea by clinicians practicing other specialties during the study period. Reporting of a diagnosis of sleep apnea varied by obesity prevalence and health insurance status across U.S. geographic regions.

Sleep-Disordered Breathing-Do We Have to Change Gears in Heart Failure?

The majority of patients with heart failure have sleep-disordered breathing (SDB)—with central (rather than obstructive) sleep apnoea becoming the predominant form in those with more severe disease. Cyclical apnoeas and hypopnoeas are associated with sleep disturbance, hypoxaemia, haemodynamic changes, and sympathetic activation. Such patients have a worse prognosis than those without SDB. Mask-based therapies of positive airway pressure targeted at SDB can improve measures of sleep quality and partially normalise the sleep and respiratory physiology, but recent randomised trials of cardiovascular outcomes in central sleep apnoea have been neutral or suggested the possibility of harm, likely from increased sudden death. Further randomised outcome studies (with cardiovascular mortality and hospitalisation endpoints) are required to determine whether mask-based treatment for SDB is appropriate for patients with chronic systolic heart failure and obstructive sleep apnoea, for those with heart failure with preserved ejection fraction, and for those with decompensated heart failure. New therapies for sleep apnoea—such as implantable phrenic nerve stimulators—also require robust assessment. No longer can the surrogate endpoints of improvement in respiratory and sleep metrics be taken as adequate therapeutic outcome measures in patients with heart failure and sleep apnoea.

Sleep-Disordered Breathing in Heart Failure - A Therapeutic Dilemma

Sleep-disordered breathing (SDB) occurs in approximately 50% of patients with reduced left ventricular ejection fraction receiving contemporary heart failure (HF) therapies. Obstructive (OSA) and central sleep apneas (CSA) interrupt breathing by different mechanisms but impose qualitatively similar autonomic, chemical, mechanical, and inflammatory burdens on the heart and circulation. Because contemporary evidence-based drug and device HF therapies have little or no mitigating effect on the acute or long-term consequences of such stimuli, there is a sound mechanistic rationale for targeting SDB to reduce cardiovascular event rates and prolong life. However, the promise of observational studies and randomized trials of small size and duration describing a beneficial effect of treating SDB in HF via positive airway pressure was not realized in 2 recent randomized outcome-driven trials: SAVE, which evaluated the cardiovascular effect of treating OSA in a cohort without HF, and SERVE-HF, which reported the results of a strategy of random allocation of minute-ventilation-triggered adaptive servo-ventilation (ASV) for HF patients with CSA. Whether effective treatment of either OSA or CSA improves the HF trajectory by reducing cardiovascular morbidity or mortality has yet to be definitively established. ADVENT-HF, designed to determine the effect of treating both CSA and non-sleepy OSA HF patients with a peak-airflow triggered ASV algorithm, could resolve this present clinical equipoise concerning the treatment of SDB.

Physicians Report Sleep Apnea Infrequently in Older and Older Vulnerable Adults

OBJECTIVES

To determine how often outpatient physician visits detect sleep apnea (SA) in older persons in the United States.

DESIGN

Retrospective Analysis.

SETTING

US non hospital and hospital based clinics.

PARTICIPANTS

US physicians.

MEASUREMENTS

National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey data from 1993 to 2011 were used to assess the frequency of physicians' coding diagnoses of SA in persons aged 65 and older. Which specialties are most likely to report SA, the most-common comorbid conditions reported with SA, and the likelihood of reporting SA in patient visits for dementia and preoperative care were assessed.

RESULTS

From 1993 to 2011, physicians reported SA in 0.3% of all office visits in persons aged 65 and older. SA reported in visits increased from 130,000 in 1993 to 2,070,000 in 2011, with an annual per capita visit reporting rate of 0.07% to 0.74%. In older populations, the proportion of documented SA visits by specialists rose, and that of primary care providers decreased. Older adults with a diagnosis of SA had higher average number of comorbidities than those without SA (1.8 vs 1.3). Reporting SA was low in visits with a diagnosis of dementia and classified as a preoperative visits.

CONCLUSION

In two nationwide surveys, SA reporting by physicians in elderly adults was 16 as greater in 2001 as in 1993, although reporting of SA remains infrequent (<1% of visits) even in vulnerable populations.

Patients with Cheyne-Stokes respiration and heart failure: patient tolerance after three-month discontinuation of treatment with adaptive servo-ventilation

The recent SERVE HF study concluded that patients with chronic heart failure (CHF) and Cheyne-Stokes respiration (CSR) have increased mortality when treated with adaptive servo-ventilation (ASV). We, therefore, wanted to explore if these patients tolerated discontinuation of ASV treatment. The study was a prospective post-ASV treatment observational design with a 3-month follow-up period. 14 patients from our outpatient clinic, all male, were originally diagnosed with CHF and Cheyne-Stokes respiration, which is a clinical form of central sleep apnea. Left ventricular ejection fraction (LVEF) was ≤45% when ASV treatment was initiated. Median machine use was 68 (42-78) months when the patients were instructed to terminate ASV treatment. The patients were then followed during conventional CHF treatment for 3 months. Study baseline was set the last ASV treatment day. Sleep data were collected from the machine the last day of use. Apnea-hypopnea index (AHI), LVEF, 6-min walk test and 24-h ambulatory electrocardiogram recordings were performed at baseline and at study end. Life quality data were obtained using The Minnesota Living with Heart Failure Questionaire (MLHFQ). New York Heart Association Functional Classification (NYHA) was registered. An ambulatory sleep screening was performed at study end. AHI increased significantly after 3 months without ASV treatment [from 1.6 (0.8-3.2) to 39.2 (24.3-44.1, p = 0.001)]. Quality of life (QOL) decreased significantly: 30 (13-54) at discontinuation of ASV vs. 46 (24-67) (MLHFQ) at study end, p = 0.04. Though there was no significant change in NYHA functional class, patients especially reported increased shortness of breath, reduced concentration and reduced memory after discontinuation of ASV treatment. There were no significant differences in LVEF, heart rhythm data and physical capacity. Left ventricular function was preserved indicating that discontinuation of ASV in heart failure patients does not affect cardiac capacity. There was a significant decrement in QOL that must be considered in further treatment of these patients.

Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep

The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a “marker” of disease severity or a “mediator” of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation.