Central sleep apnoea syndrome in chronic heart failure: an underestimated and treatable comorbidity

Sleep disordered breathing assessment in patient with slowly progressive neuromuscular disease

BACKGROUND

Sleep-disordered breathing (SDB) is common in patients with neuromuscular diseases (NMD). Focusing on hypercapnia may lead to the neglect of other SDB such as obstructive and/or central sleep apnea syndrome (SAS). Our objectives were to assess the risk of inappropriate SDB management according to different screening strategies and to evaluate the prevalence and determinants of isolated and overlapping sleep apnea in patients with slowly progressive NMD.

METHODS

This monocentric, cross-sectional, retrospective study analyzed medical records of adult NMD patients referred to a sleep department. Diagnostic strategies, including respiratory polygraphy (RP), nocturnal transcutaneous capnography (tcCO2), and blood gases (BG), were assessed for their performance in diagnosing SDB. Demographics and pulmonary function test results were compared between patients with or without SDB to identify predictors.

RESULTS

Among the 149 patients who underwent a full diagnostic panel (RP + tcCO2 + BG), 109 were diagnosed with SDB. Of these, 33% had isolated SAS, and central apneas were predominant. Using single diagnostic strategies would lead to inappropriate SDB management in two thirds of patients. A combination of 2 diagnostic tools resulted respectively in 21.1, 22.9 and 42.2 % of inappropriate SDB management for RP + tcCO2, RP + BG and tcCO2 + BG.

CONCLUSION

The significant prevalence of sleep apnea syndrome in patients with slowly progressive NMD highlights the need for increased awareness among clinicians. Improved diagnostics involve a systematic approach addressing both sleep apnea and diurnal and nocturnal alveolar hypoventilation to avoid inappropriate management and limit the consequences of SDB.

The Interplay Between Sleep Disorders and Cardiovascular Diseases: A Systematic Review

Non-communicable diseases (NCDs) have emerged as the predominant cause of global mortality, resulting in a substantial annual loss of human lives. Among these conditions, cardiovascular diseases (CVD) stand out as the primary cause of death. The majority of CVD cases can be attributed to certain factors that, upon modification, have the potential to significantly decrease both the incidence and severity of the disease. For numerous years, the impact of sleep disorders on cardiovascular health has been a prominent subject of extensive discussion. Chronic sleep disturbances are known to have a range of negative health consequences, with the relationship between sleep apnea and hypertension being well-established through numerous studies. However, further exploration is needed to understand other disease associations with sleep apnea and to examine the impact of various sleep disorders, aside from sleep apnea, on cardiovascular health. This systematic review assesses the available evidence on the association between various sleep disorders and cardiovascular diseases by addressing the question: Do sleep disorders contribute to or exacerbate cardiovascular diseases? After a comprehensive review, we identified 122 articles. Following this initial review, seven papers directly aligned with our research topic. Subsequently, we meticulously assessed the remaining seven papers, all meeting our predetermined criteria. Our analysis showed a strong correlation between sleep disruptions and cardiovascular health. Numerous sleep disorders, such as narcolepsy, central sleep apnea, obstructive sleep apnea, and insomnia, have shown different effects on cardiovascular outcomes. Increased risks of illnesses such as acute coronary syndrome (ACS), hypertension, cardiovascular mortality, and coronary artery calcification were included in these consequences. This systematic review underscores the need for early identification and comprehensive management of sleep disturbances to mitigate their potential adverse effects on cardiovascular well-being. Integrating strategies that address sleep disorders and cardiovascular health is imperative in enhancing overall health outcomes. This study paves the way for more effective preventive and therapeutic approaches by focusing on the relationship between sleep disorders and cardiovascular diseases.

Patient phenotype profiling in heart failure with preserved ejection fraction to guide therapeutic decision making. A scientific statement of the Heart Failure Association, the European Heart Rhythm Association of the European Society of Cardiology, and the European Society of Hypertension

Heart failure with preserved ejection fraction (HFpEF) represents a highly heterogeneous clinical syndrome affected in its development and progression by many comorbidities. The left ventricular diastolic dysfunction may be a manifestation of various combinations of cardiovascular, metabolic, pulmonary, renal, and geriatric conditions. Thus, in addition to treatment with sodium-glucose cotransporter 2 inhibitors in all patients, the most effective method of improving clinical outcomes may be therapy tailored to each patient's clinical profile. To better outline a phenotype-based approach for the treatment of HFpEF, in this joint position paper, the Heart Failure Association of the European Society of Cardiology, the European Heart Rhythm Association and the European Hypertension Society, have developed an algorithm to identify the most common HFpEF phenotypes and identify the evidence-based treatment strategy for each, while taking into account the complexities of multiple comorbidities and polypharmacy.

Mapping for Acute Transvenous Phrenic Nerve Stimulation Study (MAPS Study)

BACKGROUND

Central sleep apnea syndrome, correlated with the occurrence of heart failure, is characterized by periods of insufficient ventilation during sleep. This acute study in 15 patients aims to map the venous system and determine if diaphragmatic movement can be achieved by phrenic nerve stimulation at various locations within the venous system.

METHODS

Subjects underwent a scheduled catheter ablation procedure. During the procedural waiting time, one multielectrode electrophysiology catheter was subsequently placed at the superior and inferior vena cava and the junctions of the left jugular and left brachiocephalic vein and right jugular and right brachiocephalic vein, for phrenic nerve stimulation (1-2 seconds ON/2-3 seconds OFF, 40 Hz, pulse width 210 μs). Diaphragmatic movement was assessed manually and by a breathing mask. During a follow-up assessment between 2 and 4 weeks postprocedure, occurrence of adverse events was assessed.

RESULTS

In all patients diaphragmatic movement was induced at one or more locations using a median threshold of at least 2 V and maximally 7.5 V (i.e., e 3.3 mA, 14.2 mA). The lowest median current to obtain diaphragmatic stimulation without discomfort was found for the right brachiocephalic vein (4.7 mA). In 12/15 patients diaphragmatic movement could be induced without any discomfort, but in three patients hiccups occurred.

CONCLUSION

Diaphragmatic stimulation from the brachiocephalic and caval veins is feasible. Potential side effects should be eliminated by adapting the stimulation pattern. This information could be used to design a catheter, combining cardiac pacing with enhancing diaphragm movement during a sleep apnea episode.

Association between polymorphisms of the HSPB7 gene and Cheyne-Stokes respiration with central sleep apnea in patients with dilated cardiomyopathy and congestive heart failure

BACKGROUND

CSR-CSA is frequent in patients with CHF. Dilated cardiomyopathy (DCM) is a structural heart disease with strong genetic background, yet one of the leading etiological causes of CHF. Studies have showed that the HSPB7 gene is associated with DCM.

OBJECTIVES

We aimed to explore the prevalence of polymorphisms of the HSPB7 gene in the Chinese Han population with CSR-CSA and CHF caused by DCM.

METHODS

A total of 503 unrelated subjects of the Chinese Han population, including 283 CHF patients caused by DCM and 220 healthy controls, were involved in the study. The CHF patients were classified as the CSA-CHF group and the non-CSA-CHF group according to the PSG parameters. The rs1739843 polymorphisms of the HSPB7 gene were identified by real-time quantitative polymerase chain reaction.

RESULTS

In the present study, 35.8% of CHF patients caused by DCM had CSR-CSA. Comparison demonstrated that the CSA-CHF group had significantly higher TT genotype and T allele frequencies in the rs1739843 single nucleotide polymorphism (SNP) of the HSPB7 gene. There were no significant differences among the CC genotype distribution of the CSA-CHF group and the non-CSA-CHF group or the control group.

CONCLUSIONS

The rs1739843 polymorphism of the HSPB7 gene might be involved in the pathogenesis of CSR-CSA and CHF subjects caused by DCM in the Chinese Han population. This finding was from a genetic search for the role of the HSPB7 gene in CSR-CSA of CHF patients caused by DCM.

Validity and Predictive Value of a Portable Two-Channel Sleep-Screening Tool in the Identification of Sleep Apnea in Patients With Heart Failure

BACKGROUND

Sleep apnea is an important comorbidity in heart failure (HF) and is associated with an adverse outcome. Diagnosing sleep apnea is difficult, and polysomnography, considered to be the criterion standard, is not widely available. We assessed the validity of a portable 2-channel sleep-screening tool for the identification of sleep apnea in patients with HF.

METHODS AND RESULTS

One hundred patients with stable HF had simultaneous recordings of home-based polysomnography and the screening tool (Apnealink). To compare the apnea-hypopnea index of the screening tool with polysomnography, intraclass correlation (ICC), sensitivity, and specificity were calculated, and a Bland-Altman plot and receiver operating characteristic (ROC) curves were constructed. Ninety valid measurements with the screening tool were obtained (mean age 65.5 ± 11.0 y, 72% male, mean left ventricular ejection fraction 34.6 ± 11.0%). Agreement between the screening tool and polysomnography was high (ICC 0.85). The optimal cutoff value was apnea-hypopnea index ≥15/h (area under the ROC curve 0.94). Sensitivity and specificity were 92.9% and 91.9%, respectively.

CONCLUSIONS

The screening tool is useful in excluding the presence of sleep apnea in HF patients to refer only high-risk patients for more extensive polysomnography. This method may potentially reduce the need for the more expensive polysomnography.

Co-morbidities in heart failure

Heart failure is a clinical syndrome characterized by poor quality of life and high morbidity and mortality. Co-morbidities frequently accompany heart failure and further decrease in both quality of life and clinical outcome. We describe that the prevalence of co-morbidities in patients with heart failure is much higher compared to age-matched controls. We will specifically address the most studied organ-related co-morbidities, that is, renal dysfunction, cerebral dysfunction, anaemia, liver dysfunction, chronic obstructive pulmonary disease, diabetes mellitus and sleep apnoea. The pathophysiologic processes underlying the interaction between heart failure and co-morbid conditions are complex and remain largely unresolved. Although common risk factors are likely to contribute, it is reasonable to believe that factors associated with heart failure might cause other co-morbid conditions. Inflammation, neurohumoral pathway activation and hemodynamic changes are potential factors. We try to provide explanations for the observed association between co-morbidities and heart failure, as well as its impact on survival.

Dynamic CO₂ inhalation: a novel treatment for CSR-CSA associated with CHF

BACKGROUND

Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is very common in patients with chronic congestive heart failure (CHF). A current concept of the key pathophysiological mechanism leading to CSR-CSA is a fluctuation of PaCO2 below and above the apneic threshold. A number of therapeutic approaches for CSR-CSA have been proposed-all with varying success, some of which include various modes of positive airway pressure among other strategies. However, CO2 oscillations seen in CSR-CSA have yet to be looked at as a specific therapeutic target by current treatments.

DISCUSSION

Previous studies have shown that delivery of constant CO2 is efficacious in eliminating CSR-CSA by raising PaCO2, but there are serious concerns about the potential side effects, such as unwanted elevations in ventilation, work of breathing, and sympathetic nerve activity (SNA), and consequently CO2 inhalation therapy has not been recommended as a routine option for therapy. However, recent new studies into CO2 inhalation therapy have been made that may reshape its role as therapeutic. In this review, we will focus on the recent developments of administration of dynamic CO2 in the management of CSR-CSA in CHF patients.

Central sleep apnoea syndrome in chronic heart failure: an underestimated and treatable comorbidity

Chronic heart failure is a clinical syndrome with a high mortality and morbidity. Despite optimal therapy, five-year survival is still only 50%. Central sleep apnoea syndrome is seen in approximately 40% of patients with congestive heart failure. Sleep apnoea syndrome can be divided into two forms in these patients: obstructive sleep apnoea syndrome (OSAS) and central sleep apnoea syndrome (CSAS, Cheyne-Stokes respiration), of which CSAS is the most common. CSAS is a form of sleep apnoea in congestive heart failure which is driven by changes in pCO(2). As a consequence of apnoea-hypopnoea an imbalance in myocardial oxygen delivery/consumption ratio will develop, sympathetic and other neurohormonal systems will be activated and right and left ventricular afterload will be increased. Sleep apnoea is associated with an increased mortality in patients with systolic heart failure. Treatment of sleep apnoea increases left ventricular ejection fraction and transplant-free survival. Because of its high prevalence, poor quality of life, poor outcome, and the beneficial effects of treatment, physicians treating patients with heart failure should be aware of central sleep apnoea. There are different treatment options, but the exact effects and indications of each option have not yet been fully determined. Further studies should be done to further investigate its prevalence, and to establish the most adequate therapy for the individual patient. (Neth Heart J 2010;18:260-3.).

Heart failure in 2010

The Heart Failure Congress 2010 in Berlin presented the latest trials and trends in the medical and mechanical therapy of heart failure in the presence of impaired or preserved left ventricular ejection fraction. It covered all aspects of heart failure from epidemiology through basic and translational science to prevention. The congress highlighted new drugs, novel biomarkers, updated trials, the role of imaging in risk stratification and the importance of telecare in the reduction of heart failure readmission.