Short- and long-term effects of nocturnal oxygen therapy on sleep apnea in chronic heart failure

Thoracic Society of Australia and New Zealand clinical practice guideline on adult home oxygen therapy

This Thoracic Society of Australia and New Zealand Guideline on the provision of home oxygen therapy in adults updates a previous Guideline from 2015. The Guideline is based upon a systematic review and meta-analysis of literature to September 2022 and the strength of recommendations is based on GRADE methodology. Long-term oxygen therapy (LTOT) is recommended for its mortality benefit for patients with COPD and other chronic respiratory diseases who have consistent evidence of significant hypoxaemia at rest (PaO2 ≤ 55 mm Hg or PaO2 ≤59 mm Hg in the presence of hypoxaemic sequalae) while in a stable state. Evidence does not support the use of LTOT for patients with COPD who have moderate hypoxaemia or isolated nocturnal hypoxaemia. In the absence of hypoxaemia, there is no evidence that oxygen provides greater palliation of breathlessness than air. Evidence does not support the use of supplemental oxygen therapy during pulmonary rehabilitation in those with COPD and exertional desaturation but normal resting arterial blood gases. Both positive and negative effects of LTOT have been described, including on quality of life. Education about how and when to use oxygen therapy in order to maximize its benefits, including the use of different delivery devices, expectations and limitations of therapy and information about hazards and risks associated with its use are key when embarking upon this treatment.

Positionspapier „Schlafmedizin in der Kardiologie“, Update 2021

Es hat sich viel getan in der Welt der Schlafmedizin in der Kardiologie, weshalb eine vollwertige Überarbeitung des Positionspapiers „Schlafmedizin in der Kardiologie“ erforderlich wurde. In der aktuellen neuartigen Version finden sich nicht nur alle verfügbaren Studien, Literaturstellen und Updates zu Pathophysiologie, Diagnostik- und Therapieempfehlungen, sondern auch Ausblicke auf neue Entwicklungen und zukünftige Forschungserkenntnisse. Dieses überarbeitete Positionspapier gibt Empfehlungen für Diagnostik und Therapie von Patienten mit kardiovaskulären Erkrankungen mit schlafassoziierten Atmungsstörungen und erteilt darüber hinaus einen fundierten Überblick über verfügbare Therapien und Evidenzen, gibt aber ebenso Ratschläge wie mit Komorbiditäten umzugehen ist. Insbesondere enthält dieses überarbeitete Positionspapier aktualisierte Stellungnahmen zu schlafassoziierten Atmungsstörungen bei Patienten mit koronarer Herzerkrankung, Herzinsuffizienz, arterieller Hypertonie, aber auch für Patienten mit Vorhofflimmern. Darüber hinaus finden sich erstmals Empfehlungen zur Telemedizin als eigenes, neues Kapitel. Dieses Positionspapier bietet Kardiologen sowie Ärzten in der Behandlung von kardiovaskulären Patienten die Möglichkeit einer evidenzbasierten Behandlung der wachsend bedeutsamen und mit zunehmender Aufmerksamkeit behafteten Komorbidität schlafassoziierter Atmungsstörungen. Und nicht zuletzt besteht mit diesem neuen Positionspapier eine enge Verknüpfung mit dem neuen Curriculum Schlafmedizin der Deutschen Gesellschaft für Kardiologie, weshalb dieses Positionspapier eine Orientierung für die erworbenen Fähigkeiten des Curriculums im Umgang von kardiovaskulären Patienten mit schlafassoziierten Atmungsstörungen darstellt.

Oxygen Therapy in Sleep-Disordered Breathing

Sleep-disordered breathing (SDB) is highly prevalent in adults and leads to significant cardiovascular and neurologic sequelae. Intermittent hypoxia during sleep is a direct consequence of SDB. Administration of nocturnal supplemental oxygen (NSO) has been used as a therapeutic alternative to positive airway pressure (PAP) in SDB. NSO significantly improves oxygen saturation in OSA but is inferior to PAP in terms of reducing apnea severity and may prolong the duration of obstructive apneas. The effect of NSO on daytime sleepiness remains unclear, but NSO may improve physical function-related quality of life in OSA. Its effects on BP reduction remain inconclusive. The effects of NSO vs PAP in OSA with comorbid COPD (overlap syndrome) are unknown. NSO is effective in reducing central sleep apnea related to congestive heart failure; however, its impact on mortality and cardiovascular clinical outcomes are being investigated in an ongoing clinical trial. In conclusion, studies are inconclusive or limited regarding clinical outcomes with oxygen therapy compared with sham or PAP therapy in patients with OSA and overlap syndrome. Oxygen does mitigate central sleep apnea. This review examines the crucial knowledge gaps and suggests future research priorities to clarify the effects of optimal dose and duration of NSO, alone or in combination with PAP, on cardiovascular, sleep, and cognitive outcomes.

Soft cervical collar in obstructive sleep apnoea: a pilot study

In severe obstructive sleep apnoea, a soft cervical collar was well tolerated at night in 10 patients with no changes in polygraphy results. With the same design, a randomised controlled trial would need 246 inclusions for conclusive results. https://bit.ly/2KiU3j1.

Treatment-Emergent Central Apnea: Physiologic Mechanisms Informing Clinical Practice

The purpose of this review was to describe our management approach to patients with treatment-emergent central sleep apnea (TECSA). The emergence of central sleep apnea during positive airway pressure therapy occurs in approximately 8% of titration studies for OSA, and it has been associated with several demographic, clinical, and polysomnographic factors, as well as factors related to the titration study itself. TECSA shares similar pathophysiology with central sleep apnea. In fact, central and OSA pathophysiologic mechanisms are inextricably intertwined, with ventilatory instability and upper airway narrowing occurring in both entities. TECSA is a "dynamic" process, with spontaneous resolution with ongoing positive airway pressure therapy in most patients, persistence in some, or appearing de novo in a minority of patients. Management strategy for TECSA aims to eliminate abnormal respiratory events, stabilize sleep architecture, and improve the underlying contributing medical comorbidities. CPAP therapy remains a standard therapy for TECSA. Expectant management is appropriate given its transient nature in most cases, whereas select patients would benefit from an early switch to an alternative positive airway pressure modality. Other treatment options include supplemental oxygen and pharmacologic therapy.

Central sleep apnoea and periodic breathing in heart failure: prognostic significance and treatment options

Central sleep apnoea (CSA) including periodic breathing is prevalent in more than one-third of patients with heart failure and is highly and independently associated with poor outcomes. Optimal treatment is still debated and well-conducted studies regarding efficacy and impact on outcomes of available treatment options are limited, particularly in cardiac failure with preserved ejection fraction. While continuous positive airway pressure and oxygen reduce breathing disturbances by 50%, adaptive servoventilation (ASV) normalises breathing disturbances by to controlling the underlying mechanism of CSA. Results are contradictory regarding impact of ASV on hard outcomes. Cohorts and registry studies show survival improvement under ASV, while secondary analyses of the large SERVE-HF randomised trial showed an excess mortality in cardiac failure with reduced ejection fraction. The current priority is to understand which phenotypes of cardiac failure patients may benefit from treatment guiding individualised and personalised management.

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.

Death in patients with adaptive servo-ventilation for sleep apnea and no specific SERVE-HF profile: A case series study

Purpose

The SERVE-HF study reported a risk of cardiovascular death associated with adaptive servo-ventilation (ASV) for central sleep apnea in patients with chronic heart failure with reduced left ventricular ejection fraction (LVEF). Therefore, we adopted in May 2015 a safety procedure in our 32 patients with ASV since 2006. It led to ASV removal in four patients due to ≤45% LVEF. At the end of the procedure we noted eight cases of death. This high 25% mortality rate led us to study these cases.

Methods

The study population was derived from our database of patient follow-up from the sleep unit of our cardiovascular department.

Results

All deceased patients but one had cardiac disorders but only one matched the SERVE-HF patient profile. ASV was due to predominant central (n = 4) or mixed (n = 4) sleep apnea. Six patients died prior to our procedure including two patients who died several months after ASV cessation, one from ventricular fibrillation and one from respiratory infection. The cases with ongoing ASV consisted in one case of end-stage heart failure with asystole, two cases of cancer and one case of suicide. Two patients died after their safety procedure with no contra-indications to ASV and before study completion in all the patients, one from cancer and one from pulmonary and renal disorders.

Conclusions

In this series, no relationship became apparent between sleep apnea or ASV and death. Cardiovascular deaths were not predominant. Further study will be required to clarify the risks associated with ASV in patients with cardiovascular disease.

Impact of continuous positive airway pressure and oxygen on health status in patients with coronary heart disease, cardiovascular risk factors, and obstructive sleep apnea: A Heart Biomarker Evaluation in Apnea Treatment (HEARTBEAT) analysis

INTRODUCTION

Obstructive sleep apnea (OSA) is associated with impaired health-related quality of life (HRQL). Treatment with continuous positive airway pressure (CPAP) has variable impacts on HRQL, and this may be influenced by patient's tolerance of therapy. The objective is to determine the impact of nocturnal supplemental oxygen (NSO) and CPAP on HRQL compared with healthy lifestyle education (HLSE) in individuals with OSA.

METHODS

Patients with coronary heart disease (CHD) or at least 3 major CHD risk factors with apnea-hypopnea index of 15 to 50 events/h were randomized to CPAP, NSO, or HLSE. Health-related quality of life was assessed using the Short-Form 36, and depression was assessed with Patient Health Questionnaire-9 at baseline and 12 weeks. The treatment effect on HRQL change scores through 12 weeks was assessed using multivariable models adjusting for study site, presence of CHD at baseline, race, and baseline HRQL.

RESULTS

A total of 318 patients were randomized to 1 of 3 treatment arms with 1:1:1 ratio and 94% completed baseline and follow-up HRQL instruments. Mean Short-Form 36 scores were similar at baseline in all 3 groups ranging from 41.8±12 to 51.6±12 in various domains. In multivariable models, the CPAP group noted a significantly greater improvement than NSO in mental health (+2.33, 95% CI 0.34-4.31, P=.02) and mental composite score (+2.40, 95% CI 0.40-4.41, P=.02). Conversely, the CPAP group noted less improvement than NSO in physical function (-2.68, 95% CI -4.66 to -0.70, P=.008) and physical composite score (-2.17, 95% CI -3.82 to -0.51, P=.01). Compared with HLSE, vitality and Patient Health Questionnaire-9 improved with CPAP but not with NSO. Significant interactions were noted between treatment effects with larger differences in black and sleepy patients.

CONCLUSION

These data support the use of CPAP for improving vitality, sleepiness, mental health, social functioning, and depressive symptoms in patients with OSA and established CHD or risk factors. Nocturnal supplemental oxygen may have beneficial effects on perceived physical functioning.

Management of Sleep Apnea Syndromes in Heart Failure

Central sleep apnea (CSA) and obstructive sleep apnea (OSA) are prevalent in heart failure (HF) and associated with a worse prognosis. Nocturnal oxygen therapy may decrease CSA events, sympathetic tone, and improve left ventricular ejection fraction, although mortality benefit is unknown. Although treatment of OSA in patients with HF is recommended, therapy for CSA remains controversial. Continuous positive airway pressure use in HF-CSA may improve respiratory events, hemodynamics, and exercise capacity, but not mortality. Adaptive servo ventilation is contraindicated in patients with symptomatic HF with predominant central sleep-disordered events. The role of phrenic nerve stimulation in CSA therapy is promising.

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.