Management of Sleep Apnea Syndromes in Heart Failure

Cardiovascular diseases across OSA phenotypes: A retrospective cohort study

Background

Despite the considerable knowledge of Obstructive Sleep Apnea (OSA) implications for cardiac diseases, the evidence regarding cardiovascular complications across OSA phenotypes including Rapid Eye Movement OSA (REM-OSA) and Positional OSA (POSA) is limited. In this study, we aimed to evaluate the risk of cardiovascular diseases development and progression among patients with REM-OSA and POSA.

Methods

Based on a retrospective cohort analysis, we included polysomnography studies done in the sleep lab at the Jordan University Hospital. Regarding cardiovascular diseases, primary outcomes were Heart Failure, and 1-years Major Adverse Cardiac Events while secondary outcomes were atrial fibrillation, pulmonary hypertension, other arrhythmia, metabolic profile, and echocardiographic measurements of the heart.

Results

The total number of the included patients was 1,026 patients. POSA group had significantly lower percentage of patients with hypertension (P-value = 0.004). Additionally, systolic blood pressure and HbA1c were significantly lower among patients with POSA compared to the NPOSA group (P-value<0.050). Left ventricular end diastolic dimension was significantly higher among patients with POSA while ejection fraction was significantly lower (P-value<0.050). Patients with diabetes and mean HbA1c were significantly lower among patients with REM-OSA compared to patients with NREM-OSA (P-value = 0.015, P-value = 0.046). Multivariate regression analysis revealed that after adjusting for age, gender and preexisting comorbidities, POSA was significantly associated with lower ejection fraction and higher left ventricular diastolic diameter.

Conclusion

In conclusion, our findings indicate that POSA might be associated with huge and clinically significant heart strain and poor cardiac functions, yet it might not have a clinically significant atherogenic effect. This study should guide clinicians to identify OSA phenotypes to imply the best treatment plan to reduce its detrimental impact on cardiac muscle.

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.

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

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

Obstructive Sleep Apnea and Cardiac Arrhythmias: A Contemporary Review

Obstructive sleep apnea (OSA) is a highly prevalent disorder with a growing incidence worldwide that closely mirrors the global obesity epidemic. OSA is associated with enormous healthcare costs in addition to significant morbidity and mortality. Much of the morbidity and mortality related to OSA can be attributed to an increased burden of cardiovascular disease, including cardiac rhythm disorders. Awareness of the relationship between OSA and rhythm disorders is variable among physicians, a fact that can influence patient care, since the presence of OSA can influence the incidence, prevalence, and successful treatment of multiple rhythm disorders. Herein, we provide a review of this topic that is intentionally broad in scope, covering the relationship between OSA and rhythm disorders from epidemiology and pathophysiology to diagnosis and management, with a particular focus on the recognition of undiagnosed OSA in the general clinical population and the intimate relationship between OSA and atrial fibrillation.

Advances in Treatment of Sleep-Disordered Breathing

BACKGROUND

Sleep-disordered breathing, composed of obstructive sleep apnea (OSA) and central sleep apnea (CSA), affects millions of people worldwide carrying with it significant morbidity and mortality. Diagnosis is made by polysomnography, and severity of sleep apnea is determined by the apnea-hypopnea index (AHI). Positive airway pressure (PAP) therapy has been the gold standard in treating both OSA and CSA. PAP therapy can greatly reduce AHI burden as well as morbidity and mortality and improve quality of life.

AREAS OF UNCERTAINTY

However, patients report difficulties adhering to PAP therapy because of discomfort with mask interface, sensation of excessive pressure, and claustrophobia. Although other options exist to treat sleep apnea, such as mandibular advancement oral appliance devices, positional therapy, and surgery, these additional therapeutic modalities as current options have limitations. Emerging technology is now available to overcome hindrances to standard therapy.

DATA SOURCES

A literature search was performed from the following databases: PubMed, Cochrane Library (Cochrane Database of Systematic Reviews), and Cochrane Central Register of Controlled Trials, and FDA device database (clinicaltrial.gov).

THERAPEUTIC ADVANCES

Other modalities of treating sleep-disordered breathing now include the hypoglossal nerve stimulator, which stimulates the hypoglossal nerve during sleep to alleviate airflow obstruction by contracting the genioglossus muscle thus treating OSA. Similarly, the phrenic nerve stimulator restores a more stable breathing pattern during sleep by stimulating the phrenic nerve to activate the diaphragm during CSA. Both nerve stimulators have been shown to reduce AHI severity and improve quality of life for patients suffering from sleep-disordered breathing.

CONCLUSIONS

PAP therapy, although the gold standard, has limitations in the treatment of sleep apnea. New modalities such as hypoglossal nerve stimulator and phrenic nerve stimulator may help to overcome difficulties with adherence and offer new options for treatment of both obstructive and central sleep apnea.

Treating sleep disorders to improve blood pressure control and cardiovascular prevention: a dream come true?-a narrative review

Hypertension is one of the primary risk factors for heart disease and stroke, the leading causes of death worldwide. Current evidence supports the treatment of high blood pressure (BP) values in order to obtain a substantial reduction of cardiovascular burden. Sleep plays an important role in maintaining nocturnal BP control and nocturnal hypertension which, in turn, can be affected by the presence of sleep disorders. Whilst respiratory disturbances have been extensively studied and their causal role in the development of nocturnal hypertension has been demonstrated in both cross sectional and prospective studies, less is known about the impact of other sleep disorders such as insomnia. In this review, we aim to describe the role of sleep disorders in the development of nocturnal and diurnal hypertension. Furthermore, we aim to discuss the potential impact of the treatment of such sleep disorders on BP values as an adjunct treatment for patients with hypertension.

Arrhythmogenic mechanisms of obstructive sleep apnea in heart failure patients

Heart failure (HF) affects 23 million people worldwide and results in 300000 annual deaths. It is associated with many comorbidities, such as obstructive sleep apnea (OSA), and risk factors for both conditions overlap. Eleven percent of HF patients have OSA and 7.7% of OSA patients have left ventricular ejection fraction <50% with arrhythmias being a significant comorbidity in HF and OSA patients. Forty percent of HF patients develop atrial fibrillation (AF) and 30%-50% of deaths from cardiac causes in HF patients are from sudden cardiac death. OSA is prevalent in 32%-49% of patients with AF and there is a dose-dependent relationship between OSA severity and resistance to anti-arrhythmic therapies. HF and OSA lead to various downstream arrhythmogenic mechanisms, including metabolic derangement, remodeling, inflammation, and autonomic imbalance. (1) Metabolic derangement and production of reactive oxidative species increase late Na+ currents, decrease outward K+ currents and downregulate connexin-43 and cell-cell coupling. (2) remodeling also features downregulated K+ currents in addition to decreased Na+/K+ ATPase currents, altered Ca2+ homeostasis, and increased density of If current. (3) Chronic inflammation leads to downregulation of both Nav1.5 channels and K+ channels, altered Ca2+ homeostasis and reduced cellular coupling from alterations of connexin expression. (4) Autonomic imbalance causes arrhythmias by evoking triggered activity through increased Ca2+ transients and reduction of excitation wavefront wavelength. Thus, consideration of these multiple pathophysiological pathways (1-4) will enable the development of novel therapeutic strategies that can be targeted against arrhythmias in the context of complex disease, such as the comorbidities of HF and OSA.

The role of miR-214 in cardiovascular diseases

Cardiovascular disease (CVD) is the leading cause of death throughout the world. The increase in new patients every year leads to a demand for the identification of valid and novel prognostic and diagnostic biomarkers for the prevention and treatment of cardiovascular diseases. MicroRNAs (miRNAs) are critical endogenous small noncoding RNAs that negatively modulate gene expression by regulating its translation. miRNAs are implicated in most physiological processes of the heart and in the pathological progression of cardiovascular diseases. miR-214 is a deregulated miRNA in many pathological conditions, and it contributes to the pathogenesis of multiple human disorders, including cancer and cardiovascular diseases. miR-214 has dual functions in different cardiac pathological circumstances. However, it is considered as a promising marker in the prognosis, diagnosis and treatment of cardiovascular diseases. In this review, we discuss the role of miR-214 in various cardiac disease conditions, including ischaemic heart diseases, cardiac hypertrophy, pulmonary arterial hypertension (PAH), angiogenesis following vascular injury and heart failure.