Sleep Apnoea and Heart Failure

The Role of Sleep in Cardiovascular Disease

PURPOSE OF REVIEW

Sleep is an important component of cardiovascular (CV) health. This review summarizes the complex relationship between sleep and CV disease (CVD). Additionally, we describe the data supporting the treatment of sleep disturbances in preventing and treating CVD.

RECENT FINDINGS

Recent guidelines recommend screening for obstructive sleep apnea in patients with atrial fibrillation. New data continues to demonstrate the importance of sleep quality and duration for CV health. There is a complex bidirectional relationship between sleep health and CVD. Sleep disturbances have systemic effects that contribute to the development of CVD, including hypertension, coronary artery disease, heart failure, and arrhythmias. Additionally, CVD contributes to the development of sleep disturbances. However, more data are needed to support the role of screening for and treatment of sleep disorders for the prevention of CVD.

Effect of SGLT2-Inhibitors on Polygraphic Parameters in Elderly Patients Affected by Heart Failure, Type 2 Diabetes Mellitus, and Sleep Apnea

Obstructive sleep apneas (OSAs) and central sleep apneas (CSAs) are the most common comorbidities in Heart Failure (HF) that are strongly associated with all-cause mortality. Several therapeutic approaches have been used to treat CSA and OSA, but none have been shown to significantly improve HF prognosis. Our study evaluated the effects of a 3-months treatment with sodium-glucose cotransporter type 2 inhibitor (SGLT2i) on polygraphic parameters in patients with sleep apnea (SA) and HF, across the spectrum of ejection fraction, not treated with continuous positive air pressure (CPAP). A group of 514 consecutive elderly outpatients with HF, type 2 diabetes mellitus (T2DM) and SA, eligible for treatment with SGLT2i, were included in the investigation before starting any CPAP therapy. The two groups were compared with the t-test and Mann-Whitney test for unpaired data when appropriate. Then, a simple logistic regression model was built using 50% reduction in AHI as the dependent variable and other variables as covariates. A multivariate stepwise logistic regression model was constructed using the variables that linked with the dependent variable to calculate the odds ratio (OR) for the independent predictors associated with the reduction of 50% in AHI. The treated group experienced significant improvements in polygraphic parameters between baseline values and follow-up with reduction in AHI (28.4 ± 12.9 e/h vs. 15.2 ± 6.5 e/h; p < 0.0001), ODI (15.4 ± 3.3 e/h vs. 11.1 ± 2.6 e/h; p < 0.0001), and TC90 (14.1 ± 4.2% vs. 8.2 ± 2.0%; p < 0.0001), while mean SpO2 improved (91. 3 ± 2.3 vs. 93.8 ± 2.5); p < 0.0001. These benefits were not seen in the untreated population. The use of SGLT2i in patients suffering from HF and mixed-type SA not on CPAP therapy significantly contributes to improving polygraphic parameters.

Association of Sex With Cardiovascular Outcomes in Heart Failure Patients With Obstructive or Central Sleep Apnea

BACKGROUND

This study investigated the association of sex with cardiovascular outcomes in a prospective cohort of patients with heart failure (HF) with obstructive sleep apnea or central sleep apnea.

METHODS AND RESULTS

Patients were screened for sleep apnea on admission using multichannel cardiopulmonary monitoring from May 2015 to July 2018. The primary outcome was a composite of cardiovascular death or unplanned hospitalization for worsening HF. Ultimately, 453 patients with HF with obstructive sleep apnea or central sleep apnea were included; 71 (15.7%) and 382 (84.3%) were women and men, respectively. During a median follow-up of 2.33 years, 248 (54.7%) patients experienced the primary outcome. In the overall population, after adjusting for potential confounders, women had an increased risk of the primary outcome (66.2% versus 52.6%; hazard ratio [HR], 1.47 [95% CI, 1.05-2.04]; P=0.024) and HF rehospitalization (62.0% versus 46.6%; HR, 1.55 [95% CI, 1.10-2.19]; P=0.013) compared with men but a comparable risk of cardiovascular death (21.1% versus 23.3%; HR, 0.78 [95% CI, 0.44-1.37]; P=0.383). Likewise, in patients with HF with obstructive sleep apnea, women had a higher risk of the primary outcome (81.8% versus 46.3%, HR, 2.37 [95% CI, 1.28-4.38]; P=0.006) and HF rehospitalization (81.8% versus 44.7%, HR, 2.46 [95% CI, 1.32-4.56], P=0.004). However, in patients with HF with central sleep apnea, there was no statistically significant difference between women and men.

CONCLUSIONS

In hospitalized patients with HF, female sex was associated with an increased risk of the primary outcome and HF rehospitalization, especially in those with obstructive sleep apnea. Screening for sleep apnea should be emphasized to improve the prognosis.

REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02664818.

Effects of obstructive sleep apnea on myocardial injury and dysfunction: a review focused on the molecular mechanisms of intermittent hypoxia

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH) and is strongly associated with adverse cardiovascular outcomes. Myocardial injury and dysfunction have been commonly observed in clinical practice, particularly in patients with severe OSA. However, the underlying mechanisms remain obscure. In this review, we summarized the molecular mechanisms by which IH impact on myocardial injury and dysfunction. In brief, IH-induced cardiomyocyte death proceeds through the regulation of multiple biological processes, including differentially expressed transcription factors, alternative epigenetic programs, and altered post-translational modification. Besides cell death, various cardiomyocyte injuries, such as endoplasmic reticulum stress, occurs with IH. In addition to the direct effects on cardiomyocytes, IH has been found to deteriorate myocardial blood and energy supply by affecting the microvascular structure and disrupting glucose and lipid metabolism. For better diagnosis and treatment of OSA, further studies on the molecular mechanisms of IH-induced myocardial injury and dysfunction are essential.

Interventional management of mitral regurgitation and sleep disordered breathing: "Catching two birds with one stone"

Sleep disordered breathing (SDB), mostly constituting of obstructive and central sleep apnea (OSA and CSA, respectively), is highly prevalent in the general population, and even more among patients with cardiovascular disease, heart failure (HF) and valvular heart disease, such as mitral regurgitation (MR). The coexistence of HF, MR and SDB is associated with worse cardiovascular outcomes and increased morbidity and mortality. Pulmonary congestion, as a result of MR, can exaggerate and worsen the clinical status and symptoms of SDB, while OSA and CSA, through various mechanisms that impair left ventricular dynamics, can promote left ventricular remodelling, mitral annulus dilatation and consequently MR. Regarding treatment, positive airway pressure devices used to ameliorate symptoms in SDB also seem to result in a reduction of MR severity, MR jet fraction and an improvement of left ventricular ejection fraction. However, surgical and transcatheter interventions for MR, and especially transcatheter edge to edge mitral valve repair (TEER), seem to also have a positive effect on SDB, by reducing OSA and CSA-related severity indexes and improving symptom control. The purpose of this review is to provide a comprehensive analysis of the common pathophysiology between SDB and MR, as well as to discuss the available evidence regarding the effect of SDB treatment on MR and the effect of mitral valve surgery or transcatheter repair on both OSA and CSA.

Changes in sleep-disordered breathing from the acute to the stable phase of pulmonary embolism: The ESAET study

BACKGROUND

/Objective: Sleep-disordered breathing (SDB) may change from the acute to stable phase of some cardiovascular disorders, but little is known whether these dynamic changes also exist in pulmonary embolism (PE). This study aimed to analyze the changes in the apnea-hypopnea index (AHI) from the acute to stable phase of PE as well as the factors associated.

PATIENTS/METHODS

We conducted a prospective, longitudinal and multicenter study of consecutive adults requiring hospitalization for non-hypotensive acute PE, with a protocol including clinical, imaging (transthoracic echocardiography [TTE] and computed tomography), blood tests and a sleep study within 48 h of diagnosis of PE. After 3 months of follow-up, the sleep study was repeated. Right ventricular (RV) dysfunction was defined according to TTE criteria.

RESULTS

One hundred and eleven patients (mean age [SD]: 63 [15] years; body mass index: 28.4 [4.7] kg/m2) were included. The initial AHI was 24.4 (21.8) events/h (AHI≥5: 82.8 %; AHI≥30: 33.3 %). Seventy-seven patients (69.4 %) had RV dysfunction. In the overall cohort, the AHI decreased by 8.7 events/h from the acute to stable phase (24.4/h vs. 15.7/h; p=0.013). Patients with RV dysfunction showed a greater decrease in AHI (mean decrease 12.3/h vs. 0.43/h). In the multivariable analysis a drop of an AHI≥5 events/hour was independently associated with the presence of initial RV dysfunction (hazard ratio 3.9; 95%CI 1.3 to 12.1).

CONCLUSIONS

In hemodynamically stable patients with acute PE, there is a transient but clinically significant decrease in the AHI from the acute to stable phase, particularly when initially presenting with RV dysfunction.

The Cardiovascular Impact of Obstructive Sleep Apnea in Women: Current Knowledge and Future Perspectives

Overall, cardiovascular diseases have many sex-related differences in prevalence, clinical presentation, and outcomes. A considerable amount of evidence suggests that obstructive sleep apnea (OSA) increases the risk for several cardiovascular diseases. Only recently, the sex-related differences in cardiovascular outcomes gained interest in the literature. In this review, the authors discuss the current evidence addressing the cardiovascular impact of OSA in women. Particular attention is devoted to hypertension, target-organ damage, heart failure, atrial fibrillation, and cardiovascular events (including mortality). A research agenda is proposed to increase the understanding of the relevance of OSA in women from the Cardiology perspective.

The Interplay between Obstructive Sleep Apnea, Chronic Obstructive Pulmonary Disease, and Congestive Heart Failure: Time to Collectively Refer to Them as Triple Overlap Syndrome?

BACKGROUND AND OBJECTIVES

Obstructive sleep apnea-hypopnea syndrome (OSAHS) and chronic obstructive pulmonary disease (COPD) are independently linked to an increase in cardiovascular disease (CVD). Only a few studies have been published linking the association between overlap syndrome and congestive heart failure (CHF). This review highlights the interplay between overlap syndrome (OSAHS-COPD) and CHF.

MATERIALS AND METHODS

We thoroughly reviewed published literature from 2005 to 2022 in PubMed, Google Scholar, and Cochrane databases to explore the link between overlap syndrome and cardiovascular outcomes, specifically congestive heart failure.

RESULTS

Research indicates that individuals with overlap syndrome are more likely to develop congestive heart failure than those with COPD or OSA alone. Congestive heart failure is a common comorbidity of overlap syndrome, and it has a two-way connection with sleep-related breathing disorders, which tend to occur together more frequently than expected by chance.

CONCLUSIONS

CHF seems to have a strong relationship with OS. Further research is required to understand the relationship between OS and CHF.

Factors Associated With Residual Apnea-Hypopnea Index Variability During CPAP Treatment

BACKGROUND

CPAP is the first-line therapy for OSA. A high or variable residual apnea-hypopnea index (rAHI) reflects treatment failure and potentially is triggered by exacerbation of cardiovascular comorbidities. Previous studies showed that high rAHI and large rAHI variability are associated with underlying comorbidities, OSA characteristics at diagnosis, and CPAP equipment, including mask type and settings.

RESEARCH QUESTION

What factors are associated with predefined groups with low to high rAHI variability?

STUDY DESIGN AND METHODS

This registry-based study included patients with a diagnosis of OSA who were receiving CPAP treatment with at least 90 days of CPAP remote monitoring. We applied the hidden Markov model to analyze the day-to-day trajectories of rAHI variability using telemonitoring data. An ordinal logistic regression analysis identified factors associated with a risk of having a higher and more variable rAHI with CPAP treatment.

RESULTS

The 1,126 included patients were middle-aged (median age, 66 years; interquartile range [IQR], 57-73 years), predominantly male (n = 791 [70.3%]), and obese (median BMI, 30.6 kg/m² (IQR, 26.8-35.2 kg/m²). Three distinct groups of rAHI trajectories were identified using hidden Markov modeling: low rAHI variability (n = 393 [35%]), moderate rAHI variability group (n = 420 [37%]), and high rAHI variability group (n = 313 [28%]). In multivariate analysis, factors associated with high rAHI variability were age, OSA severity at diagnosis, heart failure, opioids and alcohol consumption, mental and behavioral disorders, transient ischemic attack and stroke, an oronasal mask, and level of leaks when using CPAP.

INTERPRETATION

Identifying phenotypic traits and factors associated with high rAHI variability will allow early intervention and the development of personalized follow-up pathways for CPAP treatment.

Vagal milieu or electrophysiologic substrate? The link between atrial fibrillation and obstructive sleep apnea

Atrial fibrillation is the most common cardiac arrhythmia with its prevalence expected to increase to 12.1 million people in the United States by 2030. Chronic underlying conditions that affect the heart and lungs predispose patients to develop atrial fibrillation. Obstructive sleep apnea is strongly associated with atrial fibrillation. Several pathophysiological mechanisms have been proposed to elucidate this relationship which includes electrophysiological substrate modification and the contribution of the autonomic nervous system. In this comprehensive review, we highlight important relationships and plausible causality between obstructive sleep apnea and atrial fibrillation which will improve our understanding in the evaluation, management, and prevention of atrial fibrillation. This is the most updated comprehensive review of the relationship between obstructive sleep apnea and atrial fibrillation.

Heart Failure with Preserved Ejection Fraction and Obstructive Sleep Apnea: A Novel Paradigm for Additional Cardiovascular Benefit of SGLT2 Inhibitors in Subjects With or Without Type 2 Diabetes

After examining the complex interplay between heart failure (HF) in its various clinical forms, metabolic disorders like nonalcoholic fatty liver disease (NAFLD), and obstructive sleep apnea (OSA) syndrome, in this mini-review we described possible favorable effects of sodium-glucose cotransporter 2 inhibitors (SGLT2is) on HF with preserved (i.e., ≥ 50%) ejection fraction (HFpEF) through enhanced cardiorenal function and visceral-subcutaneous body fat redistribution. In greater detail, on the basis of pathophysiological mechanisms underlying OSA onset and the direct positive SGLT2i effect on renal function benefiting chronic kidney disease, we emphasized the promising role of SGLT2is in prevention, rehabilitation, and treatment of patients with OSA regardless of coexisting type 2 diabetes (T2DM). Indeed, SGLT2is enhance lipolysis and fatty acid beta-oxidation. These phenomena might prevent OSA by reducing the size of visceral and subcutaneous adipose tissue and, as proven in humans and animals with T2DM, counteract NAFLD onset and progression. The aforementioned mechanisms may represent an additional SGLT2i cardioprotective effect in terms of HFpEF prevention in patients with OSA, whose NAFLD prevalence is estimated to be over 50%.