Obstructive Sleep Apnea in Heart Failure: Review of Prevalence, Treatment with Continuous Positive Airway Pressure, and Prognosis

Pooled prevalences of obstructive sleep apnea and heart failure: a systematic review and meta-analysis

Obstructive sleep apnea (OSA) is a disease with intermittent hypoxemia during sleep. It has been shown that OSA is related to several cardiovascular diseases including heart failure. Both OSA and heart failure have a close association bidirectionally. This study aimed to estimate the pooled prevalence of OSA in patients with heart failure as well as pooled prevalence of heart failure in patients with OSA. This was a systematic review with a meta-analysis. The inclusion criteria were observational or epidemiological studies conducted in adult patients with heart failure to evaluate the prevalence of OSA and patients with OSA to evaluate the prevalence of heart failure. The outcomes of this study were prevalence of OSA in patients with heart failure and prevalence of heart failure in patients with OSA. Four databases were used for systematic searching including PubMed, Science Direct, Scopus, and CINAHL Plus. Manual searches for related studies were also conducted. Proportion meta-analyses using a random-effects model were conducted to identify pooled proportion (prevalence) of heart failure in patients with OSA and vice versa. Among 3,941 articles from the four databases met the study criteria. Thirty-three studies showed the prevalence of OSA in patients with heart failure, while thirteen studies presented the prevalence of heart failure in patients with OSA. The prevalence of OSA in patients with heart failure was 38.4% (95% CI 31.9 to 45.2; I2 of 96.1%). Using a diagnostic criterion of OSA of more than 10 events/hr had the highest prevalence of OSA in patients with heart failure at 53.4% (95% CI 42.0 to 64.5). The highest prevalence of OSA in patients with heart failure was 60.1% (95% CI 51.4 to 68.3) in a report from India. The pooled prevalence of heart failure in patients with OSA was 12.8% (95% CI 8.1 to 19.5; I2 of 94.6%). The prevalence in Romania was highest at 22.6% (95% CI 20.4 to 24.9). The pooled prevalence of OSA in patients with heart failure was higher than the pooled prevalence of heart failure in patients with OSA. The pooled prevalence rates of these associations varied among the diagnostic criteria of OSA and countries.

Obstructive Sleep Apnea and Its Cardiac Implications in the United States: An Age-Stratified Analysis Between Young and Older Adults

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep disorder associated with cardiovascular risks. This study aimed to assess the prevalence of probable OSA and its relationship with cardiovascular risks and diseases focusing on age-stratified young adults (20-40 years) and older (>40 years).

METHODS AND RESULTS

The study used a cross-sectional design, analyzing data from the National Health and Nutrition Examination Survey conducted between 2013 and 2018, comprising 9887 community-dwelling adults aged ≥20 years. Probable OSA was determined on the basis of self-report of OSA-related symptoms (eg, snoring, gasping/breath cessation while sleeping). Cardiovascular risk factors, including hypertension, diabetes, hyperlipidemia, and metabolic syndrome, were evaluated according to established guidelines. Cardiovascular diseases (CVDs) included self-reported heart conditions, including congestive heart failure, coronary heart disease, angina, heart attacks, and strokes. Individuals with probable OSA showed a significantly higher prevalence of health conditions, including hypertension (adjusted prevalence ratio [aPR], 1.19; P<0.001), diabetes (aPR, 1.17; P: 0.01), metabolic syndrome (aPR, 1.14; P<0.001), heart attack (aPR, 1.63; P<0.01), stroke (aPR, 1.41; P: 0.03), and any CVD event (aPR, 1.36; P: 0.01) after adjusting for relevant factors. Young adults with probable OSA showed higher prevalence rates of any CVD events (aPR, 3.44; P<0.001), hypertension (aPR, 1.45; P<0.001), metabolic syndrome (aPR, 1.25; P<0.001), and angina (aPR, 10.39; P<0.001).

CONCLUSIONS

The study suggests early identification and management of OSA in individuals at risk for CVD. While cross-sectional, it emphasizes that health care providers should recognize OSA as significantly associated with CVDs and its precursor risks in young adults, stressing proactive care and screening to reduce CVD risk in this population.

One size does not fit all: Perioperative management of patients with heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is recognized as an important risk factor for perioperative complications. However, anesthesia management of HFpEF patients remains a considerable challenge without clear guidance. HFpEF is heterogeneous in its pathophysiological processes, diverse clinical presentations, adverse remodeling of cardiovascular and other organs, and clinical outcomes. It is difficult to manage the disease with one fixed approach because of this. This review phenotypes HFpEF patients by combining their clinical features and anesthesia care issues. Five phenotypes of HFpEF patients are identified: A, O, P, C, and Y. The clinical features, anesthesia implications, and anesthesia management for each phenotype are highlighted and discussed. Such an approach to HFpEF patients in the operating room could deliver safe, high-quality perioperative care.

What are key characteristics of adults with advanced heart failure discharged from ICU?

BACKGROUND

As the number of people with heart failure and treatment complexity increases, many hospitals are implementing Advanced Heart Failure Intensive Care Units (AHFICU). However, little evidence concerning the clinical characteristics of people admitted to AHFICUs exists. Understanding the clinical characteristics of people admitted to the AHFICU will assist nurses with implementing tailored interventions to ensure high-quality care delivery.

AIM

The purpose of this study was to describe the clinical characteristics of people who are admitted to and discharged from an AHFICU.

STUDY DESIGN

Baseline data from a longitudinal descriptive study were collected on adults (N = 43) admitted to an AHFICU. Heart failure severity, self-management ability, cognition, sleep quality, and other clinical characteristics were assessed.

RESULTS

Most study participants were New York Heart Association functional class IV (n = 24) or class III (n = 14), indicating poor functional capacity. Over half had mild cognitive impairment and poor sleep quality was prevalent (92.7%). Participants had adequate levels of heart failure knowledge, but low levels of heart failure self-management decision-making and ability.

CONCLUSIONS

Interventions to address the unique clinical characteristics of AHFICU patients include sleep hygiene, integration of cognitive, sleep, and self-management assessments into the electronic medical record. Addressing the unique clinical needs of people with heart failure will lead to patient-centered, evidence-based, and safe care.

RELEVANCE TO CLINICAL PRACTICE

Understanding characteristics of this population addresses this evidence gap and targeted clinical interventions to address unique discharge needs of this population are proposed. Sleep quality education should be done throughout hospitalization on sleep strategies and self-management coaching to facilitate adoption of new sleep routines. Healthcare providers should ensure each patient has care support upon discharge and take cognitive status into consideration during teaching. Addressing self-management readiness should include providing scenarios as part of discharge preparation. Providers must include addressing comorbidities and how they may affect heart failure self-management, such as teaching about sleep apnea device use and encouraging compliance.

Advance in the pharmacological and comorbidities management of heart failure with preserved ejection fraction: evidence from clinical trials

The prevalence of heart failure with preserved ejection fraction (HFpEF) accounts for approximately 50% of the total heart failure population, and with the aging of the population and the increasing prevalence of hypertension, obesity, and type 2 diabetes (T2DM), the incidence of HFpEF continues to rise and has become the most common subtype of heart failure. Compared with heart failure with reduced ejection fraction, HFpEF has a more complex pathophysiology and is more often associated with hypertension, T2DM, obesity, atrial fibrillation, renal insufficiency, pulmonary hypertension, obstructive sleep apnea, and other comorbidities. HFpEF has generally been considered a syndrome with high phenotypic heterogeneity, and no effective treatments have been shown to reduce mortality to date. Diuretics and comorbidity management are traditional treatments for HFpEF; however, they are mostly empirical due to a lack of clinical evidence in the setting of HFpEF. With the EMPEROR-Preserved and DELIVER results, sodium-glucose cotransporter 2 inhibitors become the first evidence-based therapies to reduce rehospitalization for heart failure. Subgroup analyses of the PARAGON-HF, TOPCAT, and CHARM-Preserved trials suggest that angiotensin receptor-neprilysin inhibitors, spironolactone, and angiotensin II receptor blockers may be beneficial in patients at the lower end of the ejection fraction spectrum. Other potential pharmacotherapies represented by non-steroidal mineralocorticoid receptor antagonists finerenone and antifibrotic agent pirfenidone also hold promise for the treatment of HFpEF. This article intends to review the clinical evidence on current pharmacotherapies of HFpEF, as well as the comorbidities management of atrial fibrillation, hypertension, T2DM, obesity, pulmonary hypertension, renal insufficiency, obstructive sleep apnea, and iron deficiency, to optimize the clinical management of HFpEF.

The Emergence of Inpatient Sleep Medicine: Screening for Sleep Disordered Breathing to Reduce the Burden of Cardiovascular Disease

Purpose of Review

Treatment of obstructive sleep apnea (OSA) has historically been centered on outpatients given sleep testing is performed on an outpatient basis. Much of this practice originates from insurers only covering sleep testing on an outpatient basis. Over the last decade, there have been innovations made in the portability of sleep monitors which have allowed sleep testing on inpatients to be facilitated. There is also emerging data that inpatient sleep testing may reduce readmissions and healthcare costs in certain cardiovascular conditions. Accordingly, this review aims to provide comprehensive coverage of recent advances in the practice of inpatient sleep medicine and its effect on reducing the burden of cardiovascular disease.

Recent Findings

Chief cardiovascular diseases that intersect with OSA in inpatients are stroke, atrial fibrillation, and heart failure. There is data from the National Inpatient Sample comparing arrhythmia burdens in patients with OSA and HFpEF showing that OSA patients have higher mortality rates, hospital durations, and medical costs. Also, OSA is associated with higher burdens of arrhythmia. It is currently unknown whether treatment of inpatients with PAP therapy lowers the occurrence of arrhythmias. Recent data suggests that costs for heart failure patients with OSA that are readmitted are higher than those for heart failure patients without OSA. A recent analysis of patients with HFpEF (heart failure with preserved ejection fraction) and OSA showed that the PAP adherent patients had fewer healthcare related costs, lower readmission rates, and fewer emergency room visits than those that were nonadherent. In broader terms, rapid initiation of PAP therapy in a large administration database query of 23 million Medicare patients appears to reduce annual healthcare costs and reduce readmissions although further study is required.

Summary

OSA is globally underdiagnosed, with an estimated one billion individuals affected. OSA's pathogenesis involves a combination of risk factors, such as obesity, age, and increased neck circumference that contribute to fragmented sleep patterns and in turn, numerous cardiovascular comorbidities, such as stroke, atrial fibrillation, and coronary artery disease. Recently, inpatient sleep medicine programs have emerged as a promising avenue for improving diagnosis, patient safety, and potentially reducing readmissions. Integrating inpatient sleep medicine into healthcare systems to address the significant health and economic burden associated with undiagnosed OSA. Improved coverage of inpatient sleep testing and services will be a key driver of addressing inpatient gaps in sleep medicine care. The current research findings provide a bedrock from which further investigations may proceed in a prospective and randomized, controlled fashion to further clarify the effects of treatment of OSA on cardiovascular outcomes of inpatients.

Use of invasive cardiopulmonary exercise testing to diagnose preload reserve failure in patients with liver disease

In this case series, we describe the use of invasive cardiopulmonary exercise testing (iCPET) to diagnose heart failure due to preload reserve failure in two patients with progressive dyspnoea. We demonstrate that underlying liver disease contributes to preload reserve failure as a cause of exertional dysfunction. In liver diseases such as non-alcoholic fatty liver disease (NAFLD), fibrotic changes to the sinusoidal liver architecture occur leading to an increased transhepatic sinusoidal pressure gradient. Even at the earliest stage of hepatic fibrosis in patients with NAFLD, changes in hepatic blood flow are seen due to outflow block in the sinusoidal area. In this way, changes to the sinusoidal liver architecture can lead to limitations in preload reserve. This case series describes two patients with exertional dyspnoea found to have preload failure on iCPET due to underlying liver disease.

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.

Association between Sleep Duration and Left Ventricular Hypertrophy for Patients with Type 2 Diabetes Mellitus

Objective

In this study, we aimed to estimate the impact of sleep duration on left ventricular hypertrophy (LVH) in type 2 diabetes mellitus (T2DM).

Methods

Consecutive patients with T2DM undergoing transthoracic echocardiography (TTE) in our center from October 2017 to February 2021 were analyzed. The association of the risk of LVH in T2DM patients was evaluated using univariable and multivariable logistic regression analyses.

Results

This study finally included 2689 adult patients (mean age 51.8 ± 12.5 years, 56.2% men, mean sleep duration 7.6 ± 1.4 hours per day). Of all patients, 655 (24.4%) patients were diagnosed with LVH and 2034 did not have LVH. All patients were adults and were diagnosed with T2DM. In the univariate and multivariate regression analyses, gender, sleep duration, body mass index (BMI), waist, hemoglobin (Hb), blood creatinine (Cr), and high-density lipoprotein cholesterol (HDL-c) were associated with LVH. In the restricted cubic spline (RCS) model, the cut-off points of sleep duration given refer to the group of patients with T2DM and LVH were 8 hours per day. With the cut-off points, the multivariable analysis demonstrated that, for diabetic patients, LVH was significantly correlated with a sleep duration of 8 hours per day, hemoglobin, blood urea nitrogen (BUN), and HDL-c.

Conclusion

For patients with T2DM, long sleep duration (>8 hours per day), hemoglobin, BUN, and HDL-c were independently associated with LVH. This trial is registered with NCT03811470.

Cardiopulmonary interactions in left heart failure

The primary impact of ventilation and ventilatory efforts on left ventricular (LV) function in left ventricular dysfunction relate to how changes in intrathoracic pressure (ITP) alter the pressure gradients for venous return into the chest and LV ejection out of the chest. Spontaneous inspiratory efforts by decreasing ITP increase both of these pressure gradients increasing venous blood flow and impeding LV ejection resulting in increased intrathoracic blood volume. In severe heart failure states when lung compliance is reduced, or airway resistance is increased these negative swings in ITP can be exacerbated leading to LV failure and acute cardiogenic pulmonary edema. By merely reversing these negative swings in ITP by the use of non-invasive continuous positive airway pressure (CPAP), these profoundly detrimental forces can be immediately reversed, and cardiovascular stability can be restored in moments. This forms the clinical rationale for the immediate use of CPAP for the treatment of acute cardiogenic pulmonary edema. Increasing ITP during positive pressure ventilation decreases the pressure gradients for venous return and LV ejection decreasing intrathoracic blood volume. In a hypovolemic patient even with LV dysfunction this can result in hypotension due to inadequate LV preload. Minor increases in ITP as occur using pressure-limited positive-pressure ventilation primarily reverse the increased LV afterload of negative swings in ITP and if fluid overload was already present, minimally alter cardiac output. The effect of changes in lung volume on LV function are related primarily to its effects on right ventricular (RV) function through changes in pulmonary vascular resistance and overdistention (hyperinflation). In acute lung injury with alveolar collapse, positive pressure ventilation may reduce pulmonary vascular resistance if alveolar recruitment predominates. Hyperinflation, however, impedes diastolic filling while simultaneously increasing pulmonary vascular resistance. Thus, increasing lung volume can reduce RV afterload by reversing hypoxic pulmonary vasoconstriction or increase afterload by overdistention. Hyperinflation can also impede RV filling. All of these processes can be readily identified at the bedside using echocardiography.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

A State-of-the-Art Review on Sleep Apnea Syndrome and Heart Failure

Heart failure (HF) affects many patients worldwide every year. It represents a leading cause of hospitalization and still, today, mortality remains high, albeit the progress in treatment strategies. Several factors contribute to the development and progression of HF. Among these, sleep apnea syndrome represents a common but still underestimated factor because its prevalence is substantially higher in patients with HF than in the general population and is related to a worse prognosis. This review summarizes the current knowledge about sleep apnea syndrome coexisting with HF in terms of morbidity and mortality to provide actual and future perspectives about the diagnosis, evaluation, and treatment of this association.

The association of multidimensional sleep health with adiposity in heart failure with preserved ejection fraction

BACKGROUND

There are bi-directional relationships between sleep disturbances and obesity, both of which are prevalent in patients with heart failure with preserved ejection fraction (HFpEF). However, little is known about the sleep-obesity association in HFpEF.

OBJECTIVES

To determine associations of multidimensional sleep health, night movement, sleep fragmentation, and sleep-disordered breathing (SDB) risk with overall and regional adiposity in HFpEF patients.

METHODS

Men and women with HFpEF (n = 49) were assessed via 14-day actigraphy, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale to derive multidimensional sleep health. SDB risk was assessed via Berlin Questionnaire. Body composition was measured using anthropometry; MRI quantification of epicardial, abdominal, liver, and thigh adipose tissue was performed in a subsample (n = 22). Spearman correlation (rs) and linear regression analyses (β coefficient) were used to estimate bivariate and age-adjusted associations.

RESULTS

Multidimensional sleep health was inversely associated with BMI (rs = -0.50, p < .001; unadjusted: β = -4.00, 95%CI: -5.87, -2.13; age-adjusted: β = -2.48, 95%CI: -4.65, -0.30), thigh subcutaneous adipose tissue (rs = -0.50, p = .018; unadjusted: β = -36.95, 95%CI: -67.31, -6.59), and thigh intermuscular fat (age-adjusted: β = -0.24, 95%CI: -0.48, -0.01). Night movement and sleep fragmentation were associated with greater intermuscular thigh and lower liver fat. High SDB risk was associated with a higher visceral-to-subcutaneous ratio of abdominal adiposity and lower thigh adiposity.

CONCLUSIONS

Adverse multidimensional sleep health is associated with higher adiposity measures in HFpEF patients. Further studies are needed to determine whether intervening on sleep could ameliorate excess adiposity or whether weight loss could improve sleep quality in HFpEF.

High nocturnal periodic breathing reported by PAP adherence data predicts decompensation of heart failure

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) often coexists with heart failure (HF) and is commonly treated with positive airway pressure (PAP) therapy. Periodic breathing (PB) may be present in HF and is an indicator of poor prognosis, but there is no easy way to detect PB in an outpatient setting. However, it can be detected by analyzing PAP usage data. The study aimed to assess if high PB% detected by PAP machine could predict impending HF exacerbation and if better PAP adherence is associated with reduced hospitalization and mortality.

METHODS

We retrospectively reviewed medical records of 115 patients with OSA from the sleep clinic of our VA Medical Center. The cross-sectional data on demographics, labs, PAP adherence, PB% in the previous 30 days, echocardiogram in the previous 6 months, and hospitalizations and mortality in the subsequent 180 days were extracted. Based on left ventricular ejection fraction (LVEF), patients were classified into (1) HF with normal-midrange LVEF (LVEF ≥40%, n = 74) and (2) HF with reduced LVEF (LVEF < 40%, n = 41). Pairwise correlation and linear regressions were done to assess predictors of PB%. Binomial and logistic regressions assessed the relationship of PB% and PAP adherence with hospitalization from HF and all-cause mortality.

RESULTS

In the HF with reduced LVEF group, the mean PB% was 2.6 times higher (P < .001) and PAP adherence was 29% lower (P < .001). PB% positively correlated with brain natriuretic peptide level (r = .447, P < .01) and number of hospitalizations (r = .331, P < .01). Higher PB% negatively correlated with LVEF (r = -.423, P < .01) and estimated glomerular filtration rate (r = -.246, P < .01). Every 10% increase in PAP adherence decreased odds of hospitalization by 0.78 times (P < .001) and odds of death by 0.86 (P = .043).

CONCLUSIONS

High PB% detected by PAP machine data is a predictor of impending HF exacerbation and hospitalization. Improved PAP adherence and optimization of medical therapy may reduce hospitalization and all-cause mortality.

CITATION

Ullah MI, Tamanna S, Bhagat R. High nocturnal periodic breathing reported by PAP adherence data predicts decompensation of heart failure. J Clin Sleep Med. 2023;19(3):431-441.

Synaptic loss and gliosis in the nucleus tractus solitarii with streptozotocin-induced Alzheimer's disease

Obstructive sleep apnea is highly prevalent in Alzheimer's disease (AD). However, brainstem centers controlling respiration have received little attention in AD research, and mechanisms behind respiratory dysfunction in AD are not understood. The nucleus tractus solitarii (nTS) is an important brainstem center for respiratory control and chemoreflex function. Alterations of nTS integrity, like those shown in AD patients, likely affect neuronal processing and adequate control of breathing. We used the streptozotocin-induced rat model of AD (STZ-AD) to analyze cellular changes in the nTS that corroborate previously documented respiratory dysfunction. We used 2 common dosages of STZ (2 and 3 mg/kg STZ) for model induction and evaluated the early impact on cell populations in the nTS. The hippocampus served as control region to identify site-specific effects of STZ. There was significant atrophy in the caudal nTS of the 3 mg/kg STZ-AD group only, an area known to integrate chemoafferent information. Also, the hippocampus had significant atrophy with the highest STZ dosage tested. Both STZ-AD groups showed respiratory dysfunction along with multiple indices for astroglial and microglial activation. These changes were primarily located in the caudal and intermediate nTS. While there was no change of astrocytes in the hippocampus, microglial activation was accompanied by a reduction in synaptic density. Together, our data demonstrate that STZ-AD induces site-specific effects on all major cell types, primarily in the caudal/intermediate nTS. Both STZ dosages used in this study produced a similar outcome and can be used for future studies examining the initial symptoms of STZ-AD.

Disturbed Sleep is Not Good for the Heart: A Narrative Review

Sleep-related breathing disorders, including obstructive sleep apnea (OSA) and central sleep apnea (CSA), have a major impact on cardiovascular function. It has shown an association with hypertension, coronary artery disease, cardiac arrhythmias, sudden cardiac death, and congestive heart failure (CHF). This review focuses on highlighting the relationship between sleep apnea and CHF. We discuss the underlying pathophysiology, which involves the mechanical, neurohormonal, and inflammatory mechanisms; in addition, the similarities and differentiating clinical features of OSA in patients with CHF and without CHF. We have also discussed several treatment strategies, including weight loss, continuous positive airway pressure (CPAP), supplemental oxygen therapy, theophylline, acetazolamide, mandibular advancement device, and hypoglossal nerve stimulation (HGNS). We conclude that since there are several overlapping clinical features in patients with OSA with Heart Failure (HF) and without HF, early detection and treatment are crucial to decrease the risk of HF, coronary artery disease, and stroke.

The critical issue linking lipids and inflammation: Clinical utility of stopping oxidative stress

The formation of an atheroma begins when lipoproteins become trapped in the intima. Entrapped lipoproteins become oxidized and activate the innate immune system. This immunity represents the primary association between lipids and inflammation. When the trapping continues, the link between lipids and inflammation becomes chronic and detrimental, resulting in atherosclerosis. When entrapment ceases, the association between lipids and inflammation is temporary and healthy, and the atherogenic process halts. Therefore, the link between lipids and inflammation depends upon lipoprotein retention in the intima. The entrapment is due to electrostatic forces uniting apolipoprotein B to polysaccharide chains on intimal proteoglycans. The genetic transformation of contractile smooth muscle cells in the media into migratory secretory smooth muscle cells produces the intimal proteoglycans. The protein, platelet-derived growth factor produced by activated platelets, is the primary stimulus for this genetic change. Oxidative stress is the main stimulus to activate platelets. Therefore, minimizing oxidative stress would significantly reduce the retention of lipoproteins. Less entrapment decreases the association between lipids and inflammation. More importantly, it would halt atherogenesis. This review will analyze oxidative stress as the critical link between lipids, inflammation, and the pathogenesis of atherosclerosis. Through this perspective, we will discuss stopping oxidative stress to disrupt a harmful association between lipids and inflammation. Numerous therapeutic options will be discussed to mitigate oxidative stress. This paper will add a new meaning to the Morse code distress signal SOS-stopping oxidative stress.

Causal Association between Whole-Body Water Mass and Sleep Apnea: A Mendelian Randomization Study

Rationale: Growing evidence has suggested that body water content plays a critical role in sleep apnea. However, the causal relationship has not been established. Objectives: This study aimed to investigate whether increased whole-body water mass is causally associated with a higher risk of sleep apnea using two-sample Mendelian randomization (MR) analysis. Methods: Body water mass (BWM)-associated genetic instruments were extracted from a genome-wide association study conducted by Neale Lab, which incorporates 331,315 individuals of European ancestry. Genetic variants for sleep apnea were derived from the FinnGen dataset. MR analysis was performed using inverse variance-weighted and weight median methods, respectively. MR-Egger regression and MR-Pleiotropy Residual Sum and Outlier tests were applied to evaluate the directional pleiotropy. In addition, we performed a multivariable MR analysis that includes body mass index, snoring, and waist-to-hip ratio as covariate exposures to address their confounding effects. To elucidate mechanisms of the association between BWM and sleep apnea, we further conducted MR analysis on common edematous diseases. Results: MR estimates showed that per standard deviation increase in BWM led to an increase in the risk of sleep apnea by 49% (odds ratio [OR], 1.490; 95% confidence interval [CI], 1.308-1.696; P = 1.75 × 10^-9). The result after MR-Pleiotropy Residual Sum and Outlier correction further supports their causal association (OR, 1.414; 95% CI, 1.253-1.595; P = 1.76 × 10^-8). In addition, the multivariable MR analysis indicates a significant causal association between a higher BWM and increased risk of sleep apnea (OR, 1.204; 95% CI, 1.031-1.377; P = 0.036). Genetic predisposition to a higher BWM was also causally related to increased risk of edematous diseases. Conclusions: Our results suggested that increased BWM is a potential risk factor for sleep apnea. Pathologic edema is a possible intermediate factor mediating this causal association.

Cardiovascular Complications of Obstructive Sleep Apnea in the Intensive Care Unit and Beyond

Obstructive sleep apnea (OSA) is a common disease with a high degree of association with and possible etiological factor for several cardiovascular diseases. Patients who are admitted to the Intensive Care Unit (ICU) are incredibly sick, have multiple co-morbidities, and are at substantial risk for mortality. A study of cardiovascular manifestations and disease processes in patients with OSA admitted to the ICU is very intriguing, and its impact is likely significant. Although much is known about these cardiovascular complications associated with OSA, there is still a paucity of high-quality evidence trying to establish causality between the two. Studies exploring the potential impact of therapeutic interventions, such as positive airway pressure therapy (PAP), on cardiovascular complications in ICU patients are also needed and should be encouraged. This study reviewed the literature currently available on this topic and potential future research directions of this clinically significant relationship between OSA and cardiovascular disease processes in the ICU and beyond.

Positive airway pressure therapy in heart failure patients comorbid with obstructive sleep apnea: Cardiovascular outcomes and nighttime-duration effect

BACKGROUND

Comorbidity of obstructive sleep apnea (OSA) and heart failure (HF) is becoming increasingly common. This is a global analysis of positive airway pressure (PAP) efficacy for the cardiovascular outcomes in those HF Patients with comorbid OSA.

METHODS

Related randomized controlled trials were included. Analysed indicators covered primary outcomes (cardiac function, motor ability and life quality) and secondary outcomes (blood pressure and OSA-accompanying symptoms). Weighted mean difference was used to analyse the PAP-control difference in different experimental phases and the baseline-post difference in different groups.

RESULTS

Compared with control group, PAP was associated with a 3.48% increase in left ventricle ejection fraction (LVEF) (p < .00001) and little decrease in heart rate (HR) (p = .67). Over 6 h of mean nighttime use was associated with a greater increase in LVEF of 5.21% (p = .0002) and a significant reduction in HR of 3.81 bpm (p = .03). There was no significant difference between PAP and control group in their association with change in motor ability and life quality. Besides, PAP was associated with a 13.08 mm Hg decrease in systolic blood pressure and great improvements in OSA-accompanying symptoms: Apnea-Hypopnea Index, -23.73 e/h; mean oxygen saturation, 1.86%; minimum oxygen saturation, 8.78%; Epworth Sleepiness Scale, -1.39 point; arousal index, -16.41 e/h. There was also no significant difference in diastolic blood pressure.

CONCLUSIONS

Positive airway pressure treatment improves cardiac function in HF patients with comorbid OSA, but the improved magnitude is associated with the duration of nighttime use rather than the duration of treatment.

Effect of Simultaneous Multiplane Surgery on Cardiopulmonary Function in Patients with Moderate to Severe Obstructive Sleep Apnea-Hypopnea Syndrome and Its Curative Effect

Objective

To investigate the changes in cardiopulmonary function in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) by one-stage multiplane surgery.

Methods

70 patients with moderate and severe OSAHS underwent nasal in our hospital from July 2017 to February 2021, palatopharyngeal, and/or tongue operations simultaneously and were followed up for 6 months. The Epworth Sleeping Scale (ESS) scores of patients before and after surgery were compared to observe the surgical efficacy, and the changes in the cardiopulmonary function of patients before and after surgery were detected. The static and dynamic indexes of cardiopulmonary function, respiratory disturbance index (AHI), and blood oxygen saturation (SaO2) were compared before and after the operation.

Results

After surgery, all patients' indexes of static lung function were improved compared with that before surgery. After surgery, the percentage of maximal oxygen uptake peak to the predicted value, percentage of oxygen pulse to the predicted value, the ratio of oxygen uptake power, anaerobic threshold, and maximum ventilatory capacity per minute/maximum exercise volume were increased compared with that before surgery, and AHI and SaO2 were improved compared with that before surgery.

Conclusion

This study suggests that it is feasible for patients with OSAHS who are unable to tolerate or unwilling to undergo noninvasive assisted ventilation to undergo simultaneous surgery for multiplane stenosis. It can reduce clinical symptoms and improve cardiopulmonary function.

Sleep dysregulation in sympathetic-mediated diseases: implications for disease progression

The autonomic nervous system (ANS) plays an important role in the coordination of several physiological functions including sleep/wake process. Significant changes in ANS activity occur during wake-to-sleep transition maintaining the adequate cardiorespiratory regulation and brain activity. Since sleep is a complex homeostatic function, partly regulated by the ANS, it is not surprising that sleep disruption trigger and/or evidence symptoms of ANS impairment. Indeed, several studies suggest a bidirectional relationship between impaired ANS function (i.e. enhanced sympathetic drive), and the emergence/development of sleep disorders. Furthermore, several epidemiological studies described a strong association between sympathetic-mediated diseases and the development and maintenance of sleep disorders resulting in a vicious cycle with adverse outcomes and increased mortality risk. However, which and how the sleep/wake control and ANS circuitry becomes affected during the progression of ANS-related diseases remains poorly understood. Thus, understanding the physiological mechanisms underpinning sleep/wake-dependent sympathetic modulation could provide insights into diseases involving autonomic dysfunction. The purpose of this review is to explore potential neural mechanisms involved in both the onset/maintenance of sympathetic-mediated diseases (Rett syndrome, congenital central hypoventilation syndrome, obstructive sleep apnoea, type 2 diabetes, obesity, heart failure, hypertension, and neurodegenerative diseases) and their plausible contribution to the generation of sleep disorders in order to review evidence that may serve to establish a causal link between sleep disorders and heightened sympathetic activity.

Sleep Deficiency: A Symptoms Perspective: Exemplars from Chronic Heart Failure, Inflammatory Bowel Disease, and Breast Cancer

Sleep deficiency is associated with disabling daytime symptoms, including excessive daytime sleepiness (EDS) and fatigue. The purpose of this article is to discuss the contributions of sleep deficiency and sleep disorders to fatigue and EDS among people with chronic conditions. We use exemplars from the literature on chronic heart failure, inflammatory bowel disease, and breast cancer to (1) describe the prevalence of fatigue and EDS and their consequences; (2) examine the evidence for the contributions of sleep deficiency and sleep disorders to these symptoms; and (3) recommend implications for future research and practice.

Impact of sleep apnea and treatments on cardiovascular disease

Cardiovascular diseases (CVDs) are the leading causes of mortality worldwide, accounting for nearly 18 million deaths per year. Among other considerations, treating CVDs requires better understanding their risk factors. Sleep-disordered breathing, especially obstructive sleep apnea (OSA), is a likely contributor to several CVDs. We review key epidemiological data that addresses the link between OSA and cardiovascular outcomes such as hypertension, atrial fibrillation (AF), stroke, atherosclerosis, and heart failure (HF), and proposed pathophysiological mechanisms underlying this association. There are several biological pathways linking OSA and an increased propensity to cardiovascular diseases, and we discuss the evidence on the benefits of treatments of OSA on the prevalence of cardiovascular complications.

Prevalence and factors associated with atrial fibrillation in older patients with obstructive sleep apnea

Purpose

This study sought to identify the prevalence and factors associated with atrial fibrillation (AF) in older patients with obstructive sleep apnea (OSA) in China. 

Methods

This was an explorative cross-sectional study. Between January 2015 and October 2017, we continuously recruited 1285 older patients with OSA who underwent overnight polysomnography from sleep centers of multiple hospitals. They were assessed using 12-lead ECG or 24-h dynamic ECG, and their baseline demographics, clinical characteristics, sleep parameters, and medical history were determined. Multivariate binary logistic regression analysis was used to investigate the factors related to AF in these older patients with OSA.

Results

The clinician classified 122 (9.5%) patients as having AF. The prevalence of AF significantly increased with age (P < 0.05) but did not significantly differ between the mild, moderate, and severe OSA groups. Additionally, the prevalence of paroxysmal AF was 7.2% among the overall study population, and it increased with OSA severity or advanced age (P < 0.05). Persistent AF was noted in 2.3% participants, and the prevalence also increased with age. The logistic regression analysis showed that age (OR = 1.054, 95%CI: 1.027–1.018, P < 0.001), history of drinking (OR = 1.752, 95%CI: 1.070–2.867, P < 0.05), chronic heart disease (OR = 1.778, 95%CI: 1.156–2.736, P < 0.01), diabetes mellitus (OR = 1.792, 95%CI: 1.183–2.713, P < 0.01), and reduced diastolic function (OR = 2.373, 95%CI = 1.298–4.337, P < 0.01) were relevant to AF among participants with OSA.

Conclusion

The prevalence of AF is significantly common in older patients with OSA. Age, history of drinking, chronic heart disease, diabetes mellitus, and reduced diastolic function are independently related to AF in these patients.

Obstructive Sleep Apnea and Sleep Structure Assessed in Polysomnography and Right Ventricular Strain Parameters

Our study aimed to assess functional, structural changes of the right ventricular using strain parameters and sleep structure using polysomnography in patients with obstructive sleep apnea (OSA). Our study group consisted of 43 patients, 29 men, 14 women. The mean age was 56.36 ± 14.77. All patients underwent full night polysomnography and transthoracic echocardiography. The right ventricular global longitudinal strain was measured by 2D speckle-tracking echocardiography. The prevalence of OSA (AHI ≥ 5) was 76.7% in the studied group. We observed a significant positive correlation between OAH and average free wall strain (r = 0.37), snore and mid-free wall strain (r = 0.34), average HR, and basal free wall strain (r = 0.34). Moreover, CSB was positively correlated with basal septal strain and mid septal strain (r = 0.36 and 0.42). In summary, among patients with sleep disorders, functional disorders of the right ventricle, assessed using the strain method, are partly observed.

Social relationships and the risk of incident heart failure: results from a prospective population-based study of older men

Aims

Limited social relationships, particularly in older adults, have been implicated as a risk factor for cardiovascular disease. However, little is known about the associations between poor social relationships and heart failure incidence.

Methods and results

Prospective study of socially representative men aged 60–79 years drawn from general practices in 24 British towns and followed up for a maximum of 18 years. A total of 3698 participants with no previous diagnosis of heart failure were included. Information on social relationships was based on a combination of marital status, living circumstances, and social contacts with friends and family. These provided information on contact frequency, contact satisfaction, and a social relationship score (low to high) combining frequency and satisfaction with contact. Heart failure included both incidents non-fatal heart failure and death from heart failure. Among 3698 participants, 330 developed heart failure. Men with low compared to high frequency of contact with family and friends had an increased risk of incident heart failure [hazard ratio (HR) 1.59, 95% confidence interval (CI) 1.15–2.18]; this remained statistically significant after adjustment for social class, behavioural, and biological risk factors. Low compared to high scores for satisfaction with contacts was associated with increased risk of heart failure (adjusted HR = 1.54; 95% CI 1.14–2.07). Lower social relationship scores (combining frequency and satisfaction with contact) were associated with greater risk of incident heart failure (adjusted HR = 1.38, 95% CI 1.02–1.87). Marital status and living alone were not significantly associated with heart failure.

Conclusion

Weaker social relationships appear to increase the risk of developing heart failure in older age. Further research is needed to investigate pathways underlying these associations and to test whether interventions to strengthen social relationships can reduce the risk of heart failure.

Relationships Between Obstructive Sleep Apnea and Cardiovascular Disease: A Bibliometric Analysis (2010-2021)

Background

Obstructive sleep apnea (OSA) is a common disease that can lead to intermittent hypoxia, increased sympathetic overdrive, and excessive oxidative stress, and eventually lead to cardiovascular/cerebrovascular diseases and metabolic disorders. The prevalence of OSA is reported to be higher in people with certain cardiovascular diseases (CVD). Therefore, the relationship between OSA and CVD has been gradually favored by researchers.

Material/Methods

Data were downloaded from the Web of Science Core Collection database. Citespace was used to remove duplicated data and construct knowledge visual maps.

Results

A total of 7047 publications were obtained. The USA was the largest contributor as well as an important player in the cooperation network between nations. The leading institution was the Mayo Clinic. Our study ultimately identified the top 5 hotspots and 4 research frontiers in this field. Top 5 hotspots were: the specific types of obstructive sleep apnea-related cardiovascular and metabolic co-morbidities, the curative effects of CPAP on these co-morbidities, the specific mechanisms of co-morbidities, the importance of polysomnography on OSA and its co-morbidities with CVD, and the prevalence of OSA and its co-morbidities with CVD in particular populations. The top 4 frontiers were: the relationship between OSA and resistant hypertension, the molecular mechanisms of OSA and its co-morbidities with CVD, specific medications and treatment guidelines for the co-morbidities, and the mainstream research methods in this field.

Conclusions

This study provides insight and valuable information for researchers and helps to identify new perspectives concerning potential collaborators and cooperative institutions, hot topics, and research frontiers in this field.

Increased plasma ANGPTL7 levels with increased obstructive sleep apnea severity

BACKGROUND

Weight-loss surgery is one of the recommended methods for treating obstructive sleep apnea (OSA) in obese patients. While weight reduction is critical to relieve symptoms of OSA, the biochemical factors involved in post-surgery improvement are still unknown. We aimed to explore the link between ANGPTL7 and OSA in patients with different OSA severity. Furthermore, we examined the effect of treating OSA with bariatric surgery on ANGPTL7 level.

METHODS

We quantified levels of circulating ANGPTL7 in fasting plasma and adipose tissue samples of 88 participants before and after bariatric surgery. Confocal microscopy analyses were also performed to assess the ANGPTL7 expression in subcutaneous white adipose tissue biopsies obtained from people with moderate-to-severe OSA compared to those with none or mild OSA. The study involved 57 individuals with none or mild OSA and 31 patients with moderate-to-severe OSA.

RESULTS

Levels of circulating ANGPTL7 were significantly higher in people with moderate-to-severe OSA (1440 ± 1310 pg/ml) compared to the none or mild OSA group (734 ± 904 pg/ml, p = 0.01). The increase in ANGPTL7 correlated significantly and positively with the apnea-hypopnea index (AHI, r = .226, p = .037), and AHI-supine (r = .266, p = .019) in participants with moderate-to-severe OSA. Multivariate logistic regression analysis demonstrated an association between ANGPTL7 and OSA severity (log₂ ANGPTL7; OR =1.24, p = 0.024). ANGPTL7 levels exhibited significant positive correlations with the levels of TG and oxLDL (p-value = 0.002 and 0.01 respectively). Bariatric surgery reduced the levels of both ANGPTL7 and AHI significantly.

CONCLUSION

Here we report significantly increased levels of ANGPTL7 both in the circulation and in adipose tissue of patients with OSA, which concurred with increased inflammation and OSA severity. Levels of ANGPTL7 decreased significantly as OSA showed a significant improvement post-surgery supporting a potential role for ANGPTL7 in either OSA progression or a role in an OSA-related mechanism.

Review of the Management of Obstructive Sleep Apnea and Pharmacological Symptom Management

Nearly a billion adults around the world are affected by a disease that is characterized by upper airway collapse while sleeping called obstructive sleep apnea or OSA. The progression and lasting effects of untreated OSA include an increased risk of diabetes mellitus, hypertension, stroke, and heart failure. There is often a decrease in quality-of-life scores and an increased rate of mortality in these patients. The most common and effective treatments for OSA include continuous positive airway pressure (CPAP), surgical treatment, behavior modification, changes in lifestyle, and mandibular advancement devices. There are currently no pharmacological options approved for the standard treatment of OSA. There are, however, some pharmacological treatments for daytime sleepiness caused by OSA. Identifying and treating obstructive sleep apnea early is important to reduce the risks of future complications.

Obstructive Sleep Apnea in Adults: What Primary Care Physicians Need to Know

Obstructive sleep apnea (OSA) remains a prominent disease state characterized as the recurrent collapse of the upper airway while sleeping and is estimated to plague 936 million adults globally. Although the initial clinical presentation of OSA appears harmless, it increases the risk of cardiovascular diseases such as heart failure, stroke, and hypertension; metabolic disorders; and an overall decrease in quality of life, in addition to increasing mortality. Current treatment of OSA includes lifestyle changes, behavioral modification, mandibular advancement devices, surgical treatment, and continuous positive airway pressure, which remains the gold standard. It is crucial to identify OSA early on and initiate treatment to mitigate the adverse health risks it imposes. This review will discuss the pathophysiology, epidemiology, management strategies, and medical treatment of OSA.

The value of screening questionnaires/scoring scales for obstructive sleep apnoea in patients with atrial fibrillation

BACKGROUND

Obstructive sleep apnoea (OSA) is an important modifiable risk factor for atrial fibrillation (AF) but is underdiagnosed in this population. Currently, polysomnography is the gold standard for diagnosing OSA, but is expensive and requires overnight examination. Alternatively, home sleep apnoea testing can be used as a diagnostic tool, but also requires a complete data review. Therefore, these OSA diagnostic modalities are not ideal screening methods. Several OSA screening tools exist, but their value in patients with AF remains unclear.

AIM

To test the performance of existing screening questionnaires/scales for clinically relevant OSA in patients with AF referred for diagnostic polysomnography.

METHODS

This prospective study compared the performance of seven screening tools (Epworth Sleepiness Scale, Berlin Questionnaire, Sleep Apnea Clinical Score, NoSAS, OSA50, STOP-Bang and MOODS) with polysomnography in the detection of clinically relevant OSA in consecutive patients with AF referred to two sleep clinics.

RESULTS

A total of 100 patients referred for polysomnography and known previous AF were included. Polysomnography indicated at least clinically relevant OSA (i.e., apnoea-hypopnoea index≥15 events/hour) in 69% of cases, and 33% had severe OSA (apnoea-hypopnoea index>30 events/hour). In screening for clinically relevant OSA, only the SACS and NoSAS scores had fair areas under the curve (0.704 and 0.712, respectively). None of the seven screening tools was performant enough (i.e., had a fair area under the curve>0.7) in the detection of severe OSA.

CONCLUSIONS

In this AF cohort referred for polysomnography, clinically relevant OSA was prevalent. None of the selected screening tools showed sufficient performance as a good discriminative screening tool for clinically relevant OSA in patients with AF. Given these findings, other screening modalities for OSA should be considered in the work-up of patients with AF.

Coexistence of cardiovascular risk factors and obstructive sleep apnoea in polysomnography

OBJECTIVES

The objective of the study was to assess the relationship between the coexistence of cardiovascular risk factors (CVRFs) and the incidence and severity of obstructive sleep apnoea (OSA).

METHODS

The study involved 88 people, aged 53.76 ± 12.59 years. A questionnaire, basic anthropometric measurements, blood pressure, standard laboratory tests (total cholesterol, triglycerides and glucose) and polysomnography were performed. Each patient was assessed for the presence of CVRFs: i.e. obesity, arterial hypertension, hypercholesterolemia, hypertriglyceridemia, type 2 diabetes and smoking. OSA was diagnosed based on the apnoea and hypopnea index (AHI) in polysomnography.

RESULTS

It was documented that the mean AHI values were significantly higher in obese patients than in non-obese patients, in patients with arterial hypertension than in patients without hypertension, in patients with hypercholesterolaemia than in patients without hypercholesterolaemia and in patients declaring smoking than in non-smoking patients. The correlation analysis revealed a significant positive linear relationship between the number of CVRFs and the AHI value in polysomnography (r = 0.40, p < 0.05). Based on the regression analysis, it was documented that obesity, arterial hypertension and smoking are independent predictors of higher AHI values.

CONCLUSIONS

In the study group of patients with multiple cardiovascular risk factors, there is a directly proportional relationship between the number of cardiovascular risk factors and the AHI index in polysomnography.

Severity of spleep apnea syndrome and life-threatening tachyarrhythmias in patients with implantable cardioverter defibrillator

BACKGROUND

Sleep apnea syndrome (SAS) has been reported to be associated with a higher incidence of ventricular arrhythmias. The aim of this study was twofold: (1) to investigate whether in SAS patients receiving an implantable cardioverter defibrillator (ICD) the severity of SAS was associated with the occurrence of ventricular arrhythmias; (2) to assess whether changes in nocturnal apnoic/hypopnoic episodes may favor the occurrence of life-threatening arrhythmias, that is, sustained ventricular tachycardia (VT)/fibrillation (VF), requiring ICD intervention.

METHODS

We enrolled 46 patients with documented SAS at polysomnography (apnea/hypopnea index [AHI] > 5) who also had a left ventricle ejection fraction (LVEF) < 35% and, according to primary prevention indications, implanted an ICD (Boston Scientific Incepta) able to daily monitor apnoic/hypopnoic episodes occurring during sleep. Patients were followed at 3-month intervals.

RESULTS

At a mean follow-up of 18 months, 21 episodes of sustained VT/FV requiring ICD intervention were documented in eight patients (17.4%). Baseline AHI was significantly higher in patients with compared to those without ICD intervention. ICD interventions, however, were not preceded by any worsening of apnoic/hypopnoic episodes. The respiratory disturbance index (RDI) of the week during the event, indeed, was not different from that recorded during the previous 2 weeks (25.4 ± 11, 25.6 ± 10 and 25.1 ± 10, respectively; p = .9).

CONCLUSIONS

In patients with SAS who received an ICD for primary prevention of sudden death, those with ICD interventions showed a more severe form of the disease at baseline. ICD interventions, however, were not preceded by any significant changes in SAS severity.

A meta-analysis and trial sequential analysis of serum copeptin level in adult patients with Obstructive Sleep Apnoea Syndrome

OBJECTIVE

Copeptin can act as a stable biomarker in inflammation and stress response that obstructive sleep apnoea syndrome (OSAS), can induce oxidative stress and consequently promotes systemic inflammation. The purpose of the study is to appraise serum copeptin level in adult patients with OSAS compared to the controls.

MATERIAL AND METHODS

Electronic search was done in the databases of PubMed/Medline, Web of Science, Scopus, and Cochrane Library until June 2021, without any restrictions. For comparison of the serum copeptin level between groups, the mean difference (MD) and 95% confidence interval (CI) were calculated by the Review Manager 5.3 software. Trial sequential analysis (TSA) was used by applying TSA software.

RESULTS

Among the databases, five articles (involving 495 OSAS patients and 135 controls) were included. To report the serum copeptin level in OSAS patients compared to controls, the pooled OR became 12.21pg/mL (95%CI: 2.31 to 22.11; P=0.02) and also the pooled OR for comparison of serum copeptin level in severe versus moderate/mild OSAS patients was 5.96pg/mL (95%CI: 1.46 to 10.47; P=0.009). The results of TSA illustrated that the Z-curve has not crossed the monitoring boundary curves and did not reach the required information size.

CONCLUSIONS

The main findings recommended that copeptin had a significantly higher serum level in OSAS patients compared to controls, as well as a significantly higher level in severe patients compared to mild/moderate OSAS patients for the serum level of copeptin.

Assessment of right ventricular remodeling and dysfunction in obstructive sleep apnea syndrome: a prospective monocentric study

BACKGROUND

Obstructive sleep apnea (OSA) is a common sleep-related disorder that has been implicated in many serious cardiovascular diseases including cardiac remodeling and dysfunction. Since most investigations have focused on the left heart, little is known on right ventricular (RV) involvement in OSA. The role of the RV in the management of cardiovascular outcomes has become increasingly recognized. Early detection of subtle signs of RV dysfunction and remodeling in patients with OSA is crucial for optimal medical care.

PURPOSE

We aimed to investigate the effect of OSA and its severity on the RV structure and function using conventional echocardiography.

METHODS

We conducted a cross-sectional analytical study including patients with OSA who did not have heart failure or chronic pulmonary disease comparing them to controls without OSA. All patients underwent respiratory polygraphy at the Pneumology Department and standard echocardiography performed by the same blinded cardiologist at the Cardiology Department of Taher Sfar University Hospital.

RESULTS

A total of 139 patients with OSA and 45 controls were enrolled in the study. Amonth the patients, there were 32% (n = 44) with mild, 20% (n = 28) with moderate, and 48% (n = 67) with severe OSA. Sixty-three percent of the study population were women. The mean age was 54.1 ± 11.0 years. Early RV dilatation was present in the mild disease stage (RVID = 42.0 ± 7.7 mm vs. 32.4 ± 5.5 mm in controls; p < 0.0001) without obvious RVH. The systolic pulmonary artery pressure was significantly higher in patients with OSA (31.2 ± 8.2 vs. 20.9 ± 9.8; p < 0.0001). Tricuspid annular plane systolic excursion was borderline normal and significantly lower in patients with OSA (17.7 ± 4.7 vs. 26.0 ± 5.7, p < 0.0001). In multivariate analysis, an OSA was independently associated with RV remodeling (OR: 0.257, 95% CI [0.114-0.582], p = 0.001) but not with RV dysfunction.

CONCLUSION

OSA was independently associated with structural alterations of RV early in the disease course, suggesting that the reversibility of these deleterious effects requires earlier detection and initiation of treatment.

Diagnosis and treatment of obstructive sleep apnea and its impact on cardiovascular disease

ABSTRACT

Obstructive sleep apnea (OSA) is a prevalent disorder that has direct correlation to cardiovascular disease. Understanding the etiology and symptoms of this condition as it relates to cardiovascular disease can improve comprehensive health assessments and determine the use of appropriate screening tools. This case-based approach follows a patient through assessment, diagnosis, and treatment options. Although lifestyle behavior changes are recommended for all patients, other options, such as positive airway pressure therapy, oral appliances, implantable therapy, surgery, and pharmacological and oxygen therapies, exist and should be explored as treatment options. Yearly follow-up provides the best method for long-term treatment success. Treatment of OSA reduces the incidence of cardiac comorbidities and improves cardiovascular health.

Evaluation of Obstructive Sleep Apnea Phenotypes Treatment Effectiveness

Background and Objective: Obstructive sleep apnea (OSA) is a heterogeneous chronic sleep associated disorder. A common apnea-hypopnea index (AHI)-focused approach to OSA severity evaluation is not sufficient enough to capture the extent of OSA related risks, it limits our understanding of disease pathogenesis and may contribute to a modest response to conventional treatment. In order to resolve the heterogeneity issue, OSA patients can be divided into more homogenous therapeutically and prognostically significant groups-phenotypes. An improved understanding of OSA phenotype relationship to treatment effectiveness is required. Thus, in this study several clinical OSA phenotypes are identified and compared by their treatment effectiveness. Methods and materials: Retrospective data analysis of 233 adult patients with OSA treated with continuous positive airway pressure (CPAP) was performed. Statistical analysis of data relating to demographic and anthropometric characteristics, symptoms, arterial blood gas test results, polysomnografic and respiratory polygraphic tests and treatment, treatment results was performed. Results: 3 phenotypes have been identified: "Position dependent (supine) OSA" (Positional OSA), "Severe OSA in obese patients" (Severe OSA) and "OSA and periodic limb movements (PLM)" (OSA and PLM). The highest count of responders to treatment with CPAP was in the OSA and PLM phenotype, followed by the Positional OSA phenotype. Treatment with CPAP, despite the highest mean pressure administered was the least effective among Severe OSA phenotype. Conclusions: Different OSA phenotypes vary significantly and lead to differences in response to treatment. Thus, treatment effectiveness depends on OSA phenotypes and treatment techniques other than CPAP may be needed. This emphasizes the importance of a more individualized approach when treating OSA.

Sleep apnea, "the Ugly Duckling of the Cinderellas" in cardiovascular prevention and rehabilitation

Cardiovascular diseases are the leading cause of death and account for the largest share of health expenditure worldwide, mainly invested in hospital and secondary care. Prevention and rehabilitation strategies are nearly neglected, therefore "the Cinderellas," in the health-care budget. The World Health Organization has proposed cost-effective interventions to reduce the impact of cardiovascular diseases that include polydrug treatment for hypertension and diabetes, counselling, diet, exercise, and others. Obstructive sleep apnea is not even mentioned among these interventions; consequently, it could be "the Ugly Duckling of the Cinderellas." Obstructive sleep apnea (OSA) is characterized by the presence of obstructive apneas or hypopneas during sleep, accompanied by hypoxia; and it is a highly prevalent but under-diagnosed condition. Although awareness of sleep apnea has recently increased most facts about it remains ignored by many. Robust evidence suggests that OSA is associated with, or is an independent risk factor for, hypertension, cerebrovascular disease, ischemic heart disease, heart failure and arrhythmias and that its prevalence among some of these cardiovascular diseases is higher than 80%. The efficacy of continuous positive airway pressure treatment for obstructive sleep apnea has been established. If obstructive sleep apnea plays a significant role in cardiovascular diseases, then screening and timely appropriate treatment could reduce morbidity and mortality. Thus, the public health and economic impact of these conditions could be included in the "best buy" list of interventions. This narrative review discusses the relationship between OSA and cardiovascular diseases and how neglected the link is.

Obstructive Sleep Apnea as a Cardiovascular Risk Factor-Beyond CPAP

Patients with obstructive sleep apnea (OSA) experience repetitive partial or complete airway collapse during sleep resulting in nocturnal hypoxia-normoxia cycling, and are at increased cardiovascular risk. The number of apneas and hypopneas indexed per hour of sleep (apnea-hypopnea index) along with the associated intermittent hypoxia predict the increased cardiovascular risk; thus, their attenuation or prevention are objectives of OSA therapy. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA and, when effective, mitigates the apnea-hypopnea index and hypoxemia. As such, it is reasonable to expect CPAP would decrease cardiovascular risk. However, 3 recent randomized clinical trials of CPAP vs usual care did not show any significant effects of CPAP in attenuating incident cardiovascular events in patients with OSA. In this review, we discuss these studies in addition to potential complementary therapeutic options to CPAP (eg, neurostimulation) and conclude with suggested therapeutic targets for future interventional studies (eg, the autonomic nervous system). Although these areas of research are exciting, they have yet to be tested to any similar degree of rigour as CPAP.

Acute inorganic nitrate supplementation and the hypoxic ventilatory response in patients with obstructive sleep apnea

Patients with obstructive sleep apnea (OSA) have increased cardiovascular disease risk largely attributable to hypertension. Heightened peripheral chemoreflex sensitivity (i.e., exaggerated responsiveness to hypoxia) facilitates hypertension in these patients. Nitric oxide blunts the peripheral chemoreflex, and patients with OSA have reduced nitric oxide bioavailability. We therefore investigated the dose-dependent effects of acute inorganic nitrate supplementation (beetroot juice), an exogenous nitric oxide source, on blood pressure and cardiopulmonary responses to hypoxia in patients with OSA using a randomized, double-blind, placebo-controlled crossover design. Fourteen patients with OSA (53 ± 10 yr, 29.2 ± 5.8 kg/m², apnea-hypopnea index = 17.8 ± 8.1, 43%F) completed three visits. Resting brachial blood pressure and cardiopulmonary responses to inspiratory hypoxia were measured before, and 2 h after, acute inorganic nitrate supplementation [∼0.10 mmol (placebo), 4.03 mmol (low dose), and 8.06 mmol (high dose)]. Placebo increased neither plasma [nitrate] (30 ± 52 to 52 ± 23 μM, P = 0.26) nor [nitrite] (266 ± 153 to 277 ± 164 nM, P = 0.21); however, both increased following low (29 ± 17 to 175 ± 42 μM, 220 ± 137 to 514 ± 352 nM) and high doses (26 ± 11 to 292 ± 90 μM, 248 ± 155 to 738 ± 427 nM, respectively, P < 0.01 for all). Following placebo, systolic blood pressure increased (120 ± 9 to 128 ± 10 mmHg, P < 0.05), whereas no changes were observed following low (121 ± 11 to 123 ± 8 mmHg, P = 0.19) or high doses (124 ± 13 to 124 ± 9 mmHg, P = 0.96). The peak ventilatory response to hypoxia increased following placebo (3.1 ± 1.2 to 4.4 ± 2.6 L/min, P < 0.01) but not low (4.4 ± 2.4 to 5.4 ± 3.4 L/min, P = 0.11) or high doses (4.3 ± 2.3 to 4.8 ± 2.7 L/min, P = 0.42). Inorganic nitrate did not change the heart rate responses to hypoxia (beverage-by-time P = 0.64). Acute inorganic nitrate supplementation appears to blunt an early-morning rise in systolic blood pressure potentially through suppression of peripheral chemoreflex sensitivity in patients with OSA.NEW & NOTEWORTHY The present study is the first to examine the acute effects of inorganic nitrate supplementation on resting blood pressure and cardiopulmonary responses to hypoxia (e.g., peripheral chemoreflex sensitivity) in patients with obstructive sleep apnea (OSA). Our data indicate inorganic nitrate supplementation attenuates an early-morning rise in systolic blood pressure potentially attributable to blunted peripheral chemoreflex sensitivity. These data show proof-of-concept that inorganic nitrate supplementation could reduce the risk of cardiovascular disease in patients with OSA.

The impact of obstructive sleep apnoea severity on cardiac structure and injury

BACKGROUND

Obstructive sleep apnoea (OSA) is an important factor in the development and progression of heart failure (HF). The prevalence of OSA is higher in patients with HF than in the general population. We sought to test the hypothesis that OSA severity was predictive of ventricular function and cardiac injury [as assessed by high-sensitivity cardiac troponin I(hs-cTnI)].

METHODS

A total of 60 patients were recruited after evaluation for sleep disturbances using the Jenkins Sleep Questionnaire (JSQ) and Epworth Sleepiness Scale (ESS). Subsequently, they underwent polysomnography thus confirming the diagnosis of OSA and were equally divided into three groups according to OSA severity grade. Following polysomnography, the next morning patients underwent venous blood sampling and echocardiography.

RESULTS

We observed a statistically significant association (P = 0.009) between diastolic dysfunction grades and severity grades of OSA. All the three diastolic dysfunction variables E/A ratio, deceleration time and E/e' ratio had a significant association(P < 0.05) with severity grades of OSA. There was a marginally significant positive correlation (ρ = 0.3244, p = 0.04) between AHI events per hour and mitral E/e' ratio. There was a statistically significant association(P < 0.001) between hs-cTnI value among different severity grades of OSA.

CONCLUSIONS

Here in our study, we found OSA a potential risk factor for development of myocardial injury and diastolic dysfunction. Severe grades of OSA are associated with higher grades of diastolic dysfunction and circulating levels of hs-cTnI. These data are consistent with the notion of a vicious cycle of frequent apnoea's or hypoxemia and recurrent myocardial injury, which could increase the risk of heart failure especially diastolic dysfunction in OSA.

Pharmacologic heart failure treatment: A case-based review of current guidelines

ABSTRACT

Heart failure (HF) is a growing health problem associated with high morbidity and mortality. Use of evidence-based therapies improves clinical outcomes in patients with HF with reduced ejection fraction (HFrEF). However, in real-world research studies, adults with HFrEF were often medically undermanaged, including failure to use the right medications and failure to up titrate core HF therapies to doses similar to those used in randomized controlled trials. Although guidelines provide best-practice statements about care management, nurse practitioners and physician assistants (NPs and PAs) and clinical nurses often have questions about how to implement guideline-directed therapies in patient care management. With emerging new medications for managing HFrEF, and the possibility of new medications for patients with HF with preserved ejection fraction, complexity of care management will continue to increase. The aims of this review are to provide a summary of the 2017 updates to the national chronic HF management guidelines and use a case-based approach to discuss treatment change considerations associated with optimal guideline-based clinical care.

Curcumin prevents chronic intermittent hypoxia-induced myocardial injury

Background:

Chronic intermittent hypoxia (IH), the hallmark feature of obstructive sleep apnoea syndrome, contributes to infarct size enhancement after myocardial ischemia–reperfusion (I/R). Curcumin (Curc), the natural pigment of Curcuma longa, has been demonstrated to be beneficial in the context of myocardial injury. In this study, we assessed the effects of Curc on the maladaptive cardiac response to IH, and particularly on IH-induced hypoxia inducible factor-1 (HIF-1) expression, oxidative stress, inflammation, endoplasmic reticulum (ER) stress and apoptosis.

Methods:

Swiss/SV129 mice were exposed to normoxia or IH (21–5% FiO₂, 60 s cycles, 8 h per day, for 21 days) and treated orally with Curc (100 mg kg⁻¹ day⁻¹, oral gavage) or its vehicle. Mice were then either euthanised for heart sampling in order to perform biochemical and histological analysis, or subjected to an in vivo ischemia-reperfusion protocol in order to measure infarct size.

Results:

IH increased nuclear HIF-1α expression and superoxide anion (O₂^.–) production as well as nuclear factor kappa B (NF-kB) p65, glucose-regulated protein (Grp78) and C/EBP homologous protein (CHOP) expression. IH also induced apoptosis and increased infarct size after I/R . The IH-induced HIF-1 activation, oxidative stress, inflammation, ER stress and apoptosis were abolished by chronic Curc treatment. Curc also significantly decreased infarct size only in mice exposed to IH.

Conclusion:

Curc prevents IH-induced myocardial cell death signalling. Curc might be used as a combined therapy with continuous positive airway pressure in sleep apnoea patients with high cardiovascular risk.

Suicide by inhalation of butane gas through a homemade adaptation of a continuous positive airway pressure (CPAP) face mask

Fatal poisoning due to butane inhalation has been described in the clinical and forensic literature. We report the first case of a seventy-year-old obese man with a history of sleep apnea and depression, who was found dead in bed after inhaling butane gas through a homemade adaptation of his own continuous positive airway pressure (CPAP) face mask. The death scene investigation, autopsy findings and toxicological results are described. The cause of death was suspected to be due to asphyxia through butane inhalation.

Pacing therapies for sleep apnea and cardiovascular outcomes: A systematic review

PURPOSE

Phrenic and hypoglossal nerve pacing therapies have shown benefit in sleep apnea. We sought to analyze the role of pacing therapies in sleep apnea and their impact on heart failure.

METHODS

A comprehensive literature search in PubMed and Google Scholar from inception to August 5, 2019, was performed. A meta-analysis was performed using fixed effects model to calculate mean difference (MD) with 95% confidence interval (CI).

RESULTS

Six studies were eligible and included 626 patients, of whom 334 were in the control arm and 393 were in the experimental arm. Phrenic nerve pacing (MD - 23.20 events/h, 95% CI - 27.96 to - 18.44, p < 0.00001) and hypoglossal nerve pacing (MD - 20.24 events/h, 95% CI - 23.22 to - 17.27, p < 0.00001) were associated with improvements in apnea-hypopnea index (AHI). Phrenic nerve pacing was associated with a trend towards improvements in left ventricular ejection fraction (MD 3.95%, 95% CI - 0.04 to 7.94, p = 0.05). Hypoglossal and phrenic nerve pacing were associated with improvements in the quality of life as assessed by improvements in Epworth sleepiness scale (MD 3.71 points, 95% CI 2.89 to 4.54, p < 0.00001).

CONCLUSIONS

Our analysis suggests that phrenic and hypoglossal nerve pacing improves AHI and quality of life with a trend towards improvement in left ventricular ejection fraction, especially in central sleep apnea. Complications were high but future refinement in technology will likely improve clinical outcomes and minimize complications.

Metoprolol prevents neuronal dendrite remodeling in a canine model of chronic obstructive sleep apnea

Obstructive sleep apnea (OSA) is closely associated with central nervous system diseases and could lead to autonomic nerve dysfunction, which is often seen in neurodegenerative diseases. Previous studies have shown that metoprolol prevents several chronic OSA-induced cardiovascular diseases through inhibiting autonomic nerve hyperactivity. It remains unclear whether chronic OSA can lead to dendritic remodeling in the brain, and whether metoprolol affects the dendritic remodeling. In this study we investigated the effect of metoprolol on dendrite morphology in a canine model of chronic OSA, which was established in beagles through clamping and reopening the endotracheal tube for 4 h every other day for 12 weeks. OSA beagles were administered metoprolol (5 mg· kg⁻¹· d⁻¹). The dendritic number, length, crossings and spine density of neurons in hippocampi and prefrontal cortices were assessed by Golgi staining. And the protein levels of hypoxia-inducible factor-1α (HIF-1α) and brain-derived neurotrophic factor (BDNF) were measured by Western blotting. We showed that chronic OSA successfully induced significant brain hypoxia evidenced by increased HIF-1α levels in CA1 region and dentate gyrus of hippocampi, as well as in prefrontal cortex. Furthermore, OSA led to markedly decreased dendrite number, length and intersections, spine loss as well as reduced BDNF levels. Administration of metoprolol effectively prevented the dendritic remodeling and spine loss induced by chronic OSA. In addition, administration of metoprolol reversed the decreased BDNF, which might be associated with the metoprolol-induced neuronal protection. In conclusion, metoprolol protects against neuronal dendritic remodeling in hippocampi and prefrontal cortices induced by chronic OSA in canine.