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.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020

The prevalence of sleep disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared in order to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Because sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

Novel Non-pharmaceutical Advancements in Heart Failure Management: The Emerging Role of Technology

PURPOSE OF REVIEW

To summarise and discuss the implications of recent technological advances in heart failure care.

RECENT FINDINGS

Heart failure remains a significant source of morbidity and mortality in the US population despite multiple classes of approved pharmacological treatments. Novel cardiac devices and technologies may offer an opportunity to improve outcomes. Baroreflex Activation Therapy and Cardiac Contractility Remodelling may improve myocardial contractility by altering neurohormonal stimulation of the heart. Implantable Pulmonary Artery Monitors and Biatrial Shunts may prevent heart failure admissions by altering the trajectory of progressive congestion. Phrenic Nerve Stimulation offers potentially effective treatment for comorbid conditions. Smartphone applications offer an intriguing strategy for improving medication adherence.

SUMMARY

Novel heart failure technologies offer promise for reducing this public health burden. Randomized controlled studies are indicated for assessing the future role of these novel therapies.

Sleep Apnea Syndrome (SAS) Clinical Practice Guidelines 2020

The prevalence of sleep-disordered breathing (SDB) is reportedly very high. Among SDBs, the incidence of obstructive sleep apnea (OSA) is higher than previously believed, with patients having moderate-to-severe OSA accounting for approximately 20% of adult males and 10% of postmenopausal women not only in Western countries but also in Eastern countries, including Japan. Since 1998, when health insurance coverage became available, the number of patients using continuous positive airway pressure (CPAP) therapy for sleep apnea has increased sharply, with the number of patients about to exceed 500,000 in Japan. Although the "Guidelines for Diagnosis and Treatment of Sleep Apnea Syndrome (SAS) in Adults" was published in 2005, a new guideline was prepared to indicate the standard medical care based on the latest trends, as supervised by and in cooperation with the Japanese Respiratory Society and the "Survey and Research on Refractory Respiratory Diseases and Pulmonary Hypertension" Group, of Ministry of Health, Labor and Welfare and other related academic societies, including the Japanese Society of Sleep Research, in addition to referring to the previous guidelines. Since sleep apnea is an interdisciplinary field covering many areas, this guideline was prepared including 36 clinical questions (CQs). In the English version, therapies and managements for SAS, which were written from CQ16 to 36, were shown. The Japanese version was published in July 2020 and permitted as well as published as one of the Medical Information Network Distribution Service (Minds) clinical practice guidelines in Japan in July 2021.

The role of sleep disorders in cardiovascular diseases: Culprit or accomplice?

Sleep disorders frequently comorbid with several cardiovascular diseases (CVDs), attracting increasing scientific attention and interest. Sleep disorders include insomnia, sleep-disordered breathing, restless legs syndrome, etc. It is well known that inflammation, sympathetic activation, and endothelial dysfunction play critical roles in sleep disorders, all of which are predisposing factors for CVDs. The comorbidity of sleep disorders and CVDs may have a bidirectional relationship. Patients with CVDs may have a high incidence of sleep disorders and vice versa. This review focused on the comorbidity of sleep disorders and CVDs and discussed the potential pathophysiological mechanisms and therapeutic strategies. In addition to the existing mechanisms, this review summarized novel potential mechanisms underlying comorbidities, such as gut microbiota, orexin, and extracellular vesicles, which may provide a theoretical basis for further basic research and clinical investigations on improving therapeutic outcomes.

Natural Cannabinoids as Templates for Sleep Disturbances Treatments

The sleep-wake cycle is a complex composition of specific physiological and behavioral characteristics. In addition, neuroanatomical, neurochemical and molecular systems exerts influences in the modulation of the sleep-wake cycle. Moreover, homeostatic and circadian mechanisms interact to control the waking or sleeping states. As many other behaviors, sleep also develops pathological features that include several signs and symptoms corresponding to medical conditions known as sleep disorders.In addition to the neurobiological mechanisms modulating sleep, external elements also influence the sleep-wake cycle, including the use of Cannabis sativa (C. sativa). In this regard, and over the last decades, the interest of studying the pharmacology of Δ⁹-tetrahydrocannabinol (Δ⁹-THC), the principal psychoactive constituent of C. sativa, has been addressed. Moreover, in recent years, the focus of scientific interest has moved on to studying the second plant constituent with non-psychotropic pharmacological properties: Cannabidiol (CBD).The pharmacological and pharmaceutical interest of CBD has been focus of attention due to the accumulating body of evidence regarding the positive outcomes of using CBD for the treatment of several health issues, such as psychiatric and neurodegenerative disorders, epilepsy, etc. Since the most prominent sleep disruptions include excessive daytime sleepiness (EDS), current treatments include the use of drugs such as stimulants of antidepressants. Notwithstanding, side effects are commonly reported among the patients under prescription of these compounds. Thus, the search of novelty therapeutical approaches aimed to treat ESD may consider the use of cannabinoid-derived compounds, such as CBD. In this chapter, we will show experimental evidence regarding the potential role of CBD as a wake-inducing compound aimed to manage EDS.

Usefulness of acetazolamide in the management of diuretic resistance

Worsening symptoms and fluid overload are the hallmarks of heart failure (HF) decompensation, and fluid removal is central to improvement. Despite high-dose loop diuretics, patients with decompensated HF may develop suboptimal diuresis/diuretic resistance. Sequential nephron blockade with a combination of loop and thiazide/thiazide-like diuretics may be insufficient, resulting in poor outcomes. We present a case wherein urine output improved significantly with acetazolamide. Although the diuretic capacity of acetazolamide is weak on its own, it might be efficient in aiding the efficacy of loop diuretics. We discuss the pathophysiological basis and evidence behind its potential role in diuretic resistance. Drawing from current understanding, we propose a stepwise approach to diuresis in such patients.

Heart failure and sleep-disordered breathing: susceptibility to reduced muscle strength and preclinical congestion (SICA-HF cohort)

Aims

Increased sympathetic activation in patients with heart failure (HF) and sleep‐disordered breathing (SDB) provokes cardiac decompensation and protein degradation and could lead to muscle wasting and muscle weakness. The aim of this study was to investigate the differences in body composition, muscle function, and the susceptibility of preclinical congestion among patients with HF and SDB compared with those without SDB.

Methods and results

We studied 111 outpatients with stable HF who were enrolled into the Studies Investigating Co‐morbidities Aggravating Heart Failure. Echocardiography, short physical performance battery (SPPB), cardiopulmonary exercise testing, dual‐energy X‐ray absorptiometry, bioelectrical impedance analysis (BIA), tests of muscle strength, and polygraphy were performed. SDB was defined as apnoea/hypopnoea index (AHI) >5 per hour of sleep. Central sleep apnoea (CSA) and obstructive sleep apnoea (OSA) were defined as AHI >50% of central or obstructive origin, respectively. A total of 74 patients (66.7%) had any form of SDB [CSA (24 patients, 32.4%), OSA (47 patients, 63.5%)]. Patients with SDB showed increased muscle weakness (chair stand), reduced muscle strength, and lower values of SPPB score (P < 0.05). Patients with SDB did not show overt clinical signs of cardiac decompensation compared with those without SDB (P > 0.05) but had increased amounts of water (total body water, intracellular, and extracellular) measured using BIA (P < 0.05). Increased amounts of total body water were associated with the severity of SDB and inversely with muscle strength and exercise capacity measured by anaerobic threshold (P < 0.05). Altogether, 17 patients had muscle wasting. Of these, 11 (65%) patients had SDB (statistically not significant).

Conclusions

SDB is highly prevalent in patients with HF. Patients with SDB have lower muscle strength and tend to be more susceptible to preclinical congestion.

Monitoring for sleep-disordered breathing in heart failure

Sleep-disordered breathing (SDB) is extremely common in heart failure (HF) and it carries with it adverse symptoms and impaired survival. Sleep-disordered breathing has two main types; obstructive sleep apnoea (OSA) and central sleep apnoea (CSA), which can overlap. The differentiation between CSA and OSA is important and is recommended in recent HF guidelines, by recommending a formal sleep study. The reason is that for OSA the main therapy is a positive pressure airway mask, whereas for patients with HFrEF and CSA this mask therapy actually increases cardiovascular mortality, and therefore alternative therapies are required, such as implantable phrenic nerve stimulation to improve sleep and related daytime symptoms attributable to the CSA. This article discusses the detection, screening, and monitoring of SDB in HF patients.

Acetazolamide Therapy in Patients with Heart Failure: A Meta-Analysis

Background and objectives: Fluid overload and central sleep apnea are highly prevalent in patients with heart failure (HF). We performed this meta-analysis to assess the effects of acetazolamide therapy on acid/base balance and apnea indexes. Methods: A literature search was conducted using EMBASE, MEDLINE, and Cochrane Database from inception through 18 November 2017 to identify studies evaluating the use of acetazolamide in HF. Study results were analyzed using a random effects model. The protocol for this systematic review is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42017065401). Results: Nine studies (three randomized controlled trials and six cohort studies) with a total of 229 HF patients were enrolled. After acetazolamide treatment, there were significant decreases in serum pH (mean difference (MD) of −0.04 (95% CI, −0.06 to −0.02)), pCO₂ (MD of −2.06 mmHg (95% CI, −3.60 to −0.53 mmHg)), and serum bicarbonate levels (MD of −6.42 mmol/L (95% CI, −10.05 to −2.79 mmol/L)). When compared to a placebo, acetazolamide significantly increased natriuresis (standardized mean difference (SMD) of 0.67 (95% CI, 0.08 to 1.27)), and decreased the apnea-hypopnea index (AHI) (SMD of −1.06 (95% CI, −1.75 to −0.36)) and central apnea index (CAI) (SMD of −1.10 (95% CI, −1.80 to −0.40)). Egger’s regression asymmetry tests revealed no publication bias with p = 0.20, 0.75 and 0.59 for analysis of the changes in pH, pCO₂, and serum bicarbonate levels with use of acetazolamide in HF patients. Conclusion: Our study demonstrates significant reduction in serum pH, increase in natriuresis, and improvements in apnea indexes with use of acetazolamide among HF patients.

Sleep Disorders and Atrial Fibrillation: Current Situation and Future Directions

Atrial fibrillation (AF) is a growing health problem worldwide. In recent years, there has been a rising interest in the relationship between sleep disorders and AF. Several studies have reported higher prevalence and incidence rates of AF in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). However, some believe that OSAHS is not a risk factor for AF; but AF, by itself, is regarded as one of the possible triggers for OSAHS. In this study, the related literature investigating the association between OSAHS and AF was reviewed, and then the possible mechanisms of this interplay were discussed. To conclude, recommendations for further research in this field were presented to researchers and some points were highlighted for physicians.

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.

An Overview of the Clinical Uses, Pharmacology, and Safety of Modafinil

Modafinil (MOD) is a wakefulness-inducing compound prescribed for treatment of excessive daytime sleepiness as a consequence of sleep disturbances such as shift work sleep disorder, obstructive sleep apnea, restless leg syndrome, or narcolepsy. While providing effective results in patients with sleepiness, MOD also produces positive outcomes in the management of fatigue associated with different conditions including depression, cancer, or tiredness in military personnel. Although there is clear evidence of the stimulant effects of MOD, current data also show that administration of this drug apparently induces positive neurobiological effects, such as improvement in memory. However, serious concerns have been raised since some reports have suggested MOD dependence. Taken together, these findings highlight the need to characterize the changes induced by MOD which have been observed in several neurobiological functions. Moreover, further work should follow up on the likely long-term effects of this drug if used for treatment of drowsiness and tiredness. Here, we review and summarize recent findings of the medical uses of MOD in the management of sleepiness and fatigue associated with depression or cancer as well as exhaustion in military personnel. We also discuss the available literature related with the cognitive enhancing properties of this stimulant, as well as what is known and unknown about MOD addiction.