Nocturnal Arrhythmias across a spectrum of obstructive and central sleep-disordered breathing in older men: outcomes of sleep disorders in older men (MrOS sleep) study

Nocturnal Cardiac Arrhythmias in Heart Failure With Obstructive and Central Sleep Apnea

BACKGROUND

Both OSA and central sleep apnea (CSA) may contribute to nocturnal cardiac arrhythmias (NCAs). Data are scarce regarding the prevalence of clinically important nocturnal atrial and ventricular arrythmias in patients with heart failure with reduced ejection fraction (HFrEF) and OSA or CSA.

RESEARCH QUESTION

In a cohort of patients with HFrEF, how does the prevalence of NCA compare among those with OSA, CSA, and those with no to mild sleep apnea? Is the severity of OSA or CSA associated with atrial and ventricular NCAs?

STUDY DESIGN AND METHODS

This cross-sectional analysis is an ancillary study of the Effect of Adaptive Servo Ventilation on Survival and Hospital Admissions in Heart Failure (ADVENT-HF) trial. We compared the prevalence of NCAs (excessive supraventricular ectopic activity [ESVEA], defined as premature atrial complexes ≥30/h or supraventricular tachycardia ≥ 20 beats); atrial fibrillation/flutter [AF]; and > 10 premature ventricular complexes [PVC/h]) on ECGs from polysomnograms of patients with HFrEF between those with OSA (apnea-hypopnea index [AHI ≥ 15 events/h]), those with CSA (AHI ≥ 15 events/h), and those with no to mild sleep apnea (AHI < 15 events/h [control]).

RESULTS

The prevalence of ESVEA was higher in patients with OSA (n = 430) and CSA (n = 150) compared with control participants (n = 76): 0%, 9%, and 12%, respectively. The prevalence of AF in the control, OSA, and CSA groups was 9%, 17%, and 27%; the prevalence of > 10 PVC/h was 45%, 59%, and 63%. In multivariable regression analyses, premature atrial complexes/h was associated with OSA severity (obstructive AHI: 22.4% increase per 10 events/h [95% CI, 5.2-42.3; P = .009), although neither obstructive nor central AHI was associated with AF or > 10 PVC/h.

INTERPRETATION

In patients with HFrEF, the prevalences of nocturnal ESVEA, AF, and PVC > 10/h were higher in those with OSA or CSA than in those without OSA or CSA, and OSA severity was related to the burden of nocturnal atrial ectopy. Severity of OSA or CSA was not significantly related to AF or > 10 PVC/h.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01128816; URL: www.

CLINICALTRIALS

gov.

Power-law properties of nocturnal arrhythmia avalanches: A novel marker for incident cardiovascular events

BACKGROUND

Bursting nonsustained cardiac arrhythmia events are a common observation during sleep.

OBJECTIVES

The purpose of this study was to investigate the hypothesis that nocturnal arrhythmia episode durations could follow a power law, whose exponent could predict long-term clinical outcomes.

METHODS

We defined "nocturnal arrhythmia avalanche" (NAA) as any instance of a drop in electrocardiographic (ECG) template-matched R-R intervals ≥30% of R-R baseline, followed by a return to 90% of baseline. We studied NAA in ECG recordings obtained from the Sleep Heart Health Study (SHHS), Osteoporotic Fractures in Men Study (MrOS) Study, and Multi-Ethnic Study of Atherosclerosis (MESA). The association of nocturnal arrhythmia durations with a power-law distribution was evaluated and the association of derived power-law exponents (α) with major adverse cardiovascular (CV) events and mortality assessed with multivariable Cox regression.

RESULTS

A total of 9176 participants were studied. NAA episodes distribution was consistent with power-law vs comparator distributions in all datasets studied (positive log likelihood ratio of power-law vs exponential in MESA: 83%; SHHS: 69%; MrOS: 81%; power-law vs log-normal in MESA: 95%; SHHS: 35%; MrOS: 64%). The NAA power-law exponent (α) showed a significant association of with adverse CV outcomes (association with CV mortality: SHHS hazard ratio 1.39 [1.07-1.79], P = .012; MrOS hazard ratio 1.42 [1.02-1.94], P = .039; association with CV events: MESA HR 3.46 [1.46-8.21], P = .005) in multivariable Cox regression, after adjusting for conventional CV risk factors and nocturnal ectopic rate.

CONCLUSION

The NAA power-law exponent is a reproducible, predictive marker for incident CV events and mortality.

Sleep Apnea and Atrial Fibrillation: Clinical Features and Screening Diagnostic Options

INTRODUCTION

Obstructive sleep apnea (OSA) is associated with an increased risk of hypertension, coronary artery disease, heart failure (HF), and atrial fibrillation (AF).

MATERIALS AND METHODS

A total of 179 patients aged 34-81 years were included in the study. The median age was 63 years (interquartile range: 56-69 years). Of these patients, 105 (58.7%) were men, and 74 (41.3%) were women; there were cases of paroxysmal (n = 99), persistent (n = 64), and permanent AF (n = 16). All patients underwent investigations including respiratory sleep monitoring, echocardiography, and 24 h Holter electrocardiography monitoring. Statistical analyses were performed using IBM SPSS Statistics 26.0.

RESULTS

OSA was detected in 131 (73.2%) patients. In patients with OSA, paroxysmal AF was commonest (n = 65), followed by persistent AF (n = 51) and permanent AF (n = 15). The patients with sleep apnea had increased body mass index (33.6 kg/m2; p = 0.02), waist circumference (114 cm; p < 0.001), and neck circumference (42 cm; p < 0.001) values. HF (OR 2.9; 95% CI: 1.4-5.9; p = 0.004) and type 2 diabetes (OR 3.6; 95% CI: 1.5-8.3; p = 0.001) were more common in patients with AF and OSA. The STOP-BANG scale (AUC = 0.706 ± 0.044; 95% CI: 0.619-0.792; p < 0.001) and the Berlin questionnaire (AUC = 0.699 ± 0.044; 95% CI: 0.614-0.785) had a higher predictive ability for identifying sleep apnea.

CONCLUSIONS

Patients with AF demonstrate a high prevalence of OSA and an increased association with cardiovascular comorbidities. The STOP-BANG scale and the Berlin questionnaire can be used to screen for OSA in patients with AF.

Sleep-Disordered Breathing, Advanced Age, and Diabetes Mellitus Are Associated with De Novo Atrial Fibrillation after Cardiac Surgery

Background: Postoperative de novo atrial fibrillation (POAF) is one of the most frequently encountered complications following cardiac surgery. Despite the identification of several risk factors, the link between sleep-disordered breathing (SDB) and POAF has barely been examined. The objective of this prospective observational study was to determine whether severe SDB is associated with POAF in patients after elective coronary artery bypass grafting (CABG) surgery. Study design and methods: The incidence and preoperative predictors of in-hospital POAF were assessed in 272 patients undergoing CABG surgery at the University Medical Center Regensburg (Germany). In-hospital POAF was detected by continuous telemetry-ECG monitoring and 12-lead resting ECGs within the first seven postoperative days. POAF that occurred after hospital discharge within 60 days post CABG surgery was classified as post-hospital POAF and was ascertained by standardized phone interviews together with the patients' medical files, including routinely performed Holter-ECG monitoring at 60 days post CABG surgery. The night before surgery, portable SDB monitoring was used to assess the presence and type of severe SDB, defined by an apnea-hypopnea index ≥ 30/h. Results: The incidence of in-hospital POAF was significantly higher in patients with severe SDB compared to those without severe SDB (30% vs. 15%, p = 0.009). Patients with severe SDB suffered significantly more often from POAF at 60 days post CABG surgery compared to patients without severe SDB (14% vs. 5%, p = 0.042). Multivariable logistic regression analysis showed that severe SDB (odds ratio, OR [95% confidence interval, CI]: 2.23 [1.08; 4.61], p = 0.030), age ≥ 65 years (2.17 [1.04; 4.53], p = 0.038), and diabetes mellitus (2.27 [1.15; 4.48], p = 0.018) were significantly associated with in-hospital POAF. After additional adjustment for heart failure, the association between sleep apnea and postoperative atrial fibrillation was attenuated (1.99 [0.92; 4.31], p = 0.081). Conclusions: Amongst established risk factors, severe SDB was significantly associated with in-hospital POAF in patients undergoing CABG surgery. Whether SDB contributes to POAF independently of heart failure and whether risk for POAF may be alleviated by proper treatment of SDB merits further investigation.

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

Sex-based differences in obstructive sleep apnea and atrial fibrillation: Implication of atrial fibrillation burden

Background

Obstructive sleep apnea (OSA) is a risk factor for atrial fibrillation (AF); however, it is unclear whether AF increases the risk of OSA. Furthermore, sex differences among patients with both AF and OSA remain unclear. We aimed to determine the association between an increased AF burden and OSA and investigate the differences in clinical characteristics between women and men with AF and OSA.

Methods

This was a descriptive, cross-sectional analysis from a prospective cohort study. Patients with non-valvular AF were recruited from the cardiac electrophysiology clinic of a tertiary center; they underwent a home sleep apnea test and 14-day ambulatory electrocardiography. Moderate-to-severe OSA was defined as an apnea-hypopnea index of ≥15.

Results

Of 320 patients with AF, 53.4% had moderate-to-severe OSA, and the mean body mass index (BMI) was 25.6 kg/m2. Less women (38.2%) had moderate-to-severe OSA than men (59.3%) (p < 0.001). In the multivariate analysis, age, being a man, and BMI were significantly associated with moderate-to-severe OSA. AF burden was associated with moderate-to-severe OSA only in men (odds ratio: 1.008; 95% confidence interval: 1.001-1.014). Women and men with OSA had similar BMI (p = 0.526) and OSA severity (p = 0.754), but women were older than men (70.1 ± 1.3 vs. 63.1 ± 0.9 years, p < 0.001). Women with moderate-to-severe OSA had a lower AF burden than men did (27.6 ± 7.1 vs. 49.5 ± 3.9%, p = 0.009).

Conclusions

AF burden is a sex-specific risk factor for OSA and is limited to men. In contrast, women with both AF and OSA have a lower AF burden than men, despite being older and having similar OSA severity and body habitus. Thus, AF may develop later in women with OSA than in men.

Sleep-Disordered Breathing, Hypoxia, and Pulmonary Physiologic Influences in Atrial Fibrillation

Background We leverage a large clinical cohort to elucidate sleep-disordered breathing and sleep-related hypoxia in incident atrial fibrillation (AF) development given the yet unclear contributions of sleep-related hypoxia and pulmonary physiology in sleep-disordered breathing and AF. Methods and Results Patients who underwent sleep studies at Cleveland Clinic January 2, 2000, to December 30, 2015, comprised this retrospective cohort. Cox proportional hazards models were used to examine apnea hypopnea index, percentage time oxygen saturation <90%, minimum and mean oxygen saturation, and maximum end-tidal carbon dioxide on incident AF adjusted for age, sex, race, body mass index, cardiopulmonary disease and risk factors, antiarrhythmic medications, and positive airway pressure. Those with spirometry were additionally adjusted for forced expiratory volume in 1 second, forced vital capacity, and forced expiratory volume in 1 second/forced vital capacity. This cohort (n=42 057) was 50.7±14.1 years, 51.3% men, 74.1% White individuals, had median body mass index 33.2 kg/m2, and 1947 (4.6%) developed AF over 5 years. A 10-unit apnea hypopnea index increase was associated with 2% higher AF risk (hazard ratio [HR], 1.02 [95% CI, 1.00-1.03]). A 10-unit increase in percentage time oxygen saturation <90% and 10-unit decreases in mean and minimum oxygen saturation were associated with 6% (HR, 1.06 [95% CI, 1.04-1.08]), 30% (HR, 1.30 [95% CI, 1.18-1.42]), and 9% (HR, 1.09 [95% CI, 1.03-1.15]) higher AF risk, respectively. After adjustment for spirometry (n=9683 with available data), only hypoxia remained significantly associated with incident AF, although all coefficients were stable. Conclusions Sleep-related hypoxia was associated with incident AF in this clinical cohort, consistent across 3 measures of hypoxia, persistent after adjustment for pulmonary physiologic impairment. Findings identify a strong role for sleep-related hypoxia in AF development without pulmonary physiologic interdependence.

Relationships between Heart Chamber Morphology or Function and Respiratory Parameters in Patients with HFrEF and Various Types of Sleep-Disordered Breathing

Sleep-disordered breathing (SDB), i.e., central sleep apnea (CSA) and obstructive sleep apnea (OSA), affects the prognosis of patients with heart failure with reduced ejection fraction (HFrEF). The study assessed the relationships between heart chamber size or function and respiratory parameters in patients with HFrEF and various types of SDB. The 84 participants were patients aged 68.3 ± 8.4 years (80% men) with an average left ventricular ejection fraction (LVEF) of 25.5 ± 6.85% who qualified for cardioverter-defibrillator implantation with or without cardiac resynchronization therapy. SDB, defined by an apnea-hypopnea index (AHI) ≥ five events/hour, was diagnosed in 76 patients (90.5%); SDB was severe in 31 (36.9%), moderate in 26 (31.0%), and mild in 19 (22.6%). CSA was the most common type of SDB (64 patients, 76.2%). A direct proportional relationship existed only in the CSA group between LVEF or stroke volume (SV) and AHI (p = 0.02 and p = 0.07), and between LVEF or SV and the percentage of total sleep time spent with hemoglobin oxygen saturation < 90% (p = 0.06 and p = 0.07). In contrast, the OSA group was the only group in which right ventricle size showed a positive relationship with AHI (for basal linear dimension [RVD1] p = 0.06), mean duration of the respiratory event (for RVD1 p = 0.03, for proximal outflow diameter [RVOT proximal] p = 0.009), and maximum duration of respiratory event (for RVD1 p = 0.049, for RVOT proximal p = 0.006). We concluded that in HFrEF patients, SDB severity is related to LV systolic function and SV only in CSA, whereas RV size correlates primarily with apnea/hypopnea episode duration in OSA.

Nutritional Status and Sleep Quality Are Associated with Atrial Fibrillation in Patients with Obstructive Sleep Apnea: Results from Tokyo Sleep Heart Study

The prevalence of obstructive sleep apnea (OSA) in patients with atrial fibrillation (AF) has been observed to be much higher than in control participants without AF. Limited data exist regarding the prevalence of AF in patients with OSA. The clinical characteristics, nutritional status, and sleep parameters associated with AF in patients with OSA remain unclear. In this study, we aimed to determine the prevalence and factors associated with AF in patients with OSA from a large Japanese sleep cohort (Tokyo Sleep Heart Study). This was a single-center explorative cross-sectional study. Between November 2004 and June 2018, we consecutively recruited 2569 patients with OSA who underwent an overnight full polysomnography at our hospital. They were assessed using a 12-lead ECG and echocardiography. The clinical characteristics, sleep parameters, and medical history were also determined. Of the OSA patients, 169 (6.6%) had AF. Compared with the non-AF patients, OSA patients with AF were older and male, and they had higher prevalence of a history of alcohol consumption, hypertension, chronic kidney disease, and undernutrition, as well as a reduced ejection fraction. With regard to the sleep study parameters, OSA patients with AF had reduced slow-wave sleep and sleep efficiency, as well as higher periodic limb movements. There were no significant differences in the apnea-hypopnea index or hypoxia index between the two groups. The logistic regression analysis demonstrated that age (OR = 4.020; 95% CI: 1.895-8.527; p < 0.001), a history of alcohol consumption (OR = 2.718; 95% CI: 1.461-5.057; p = 0.002), a high CONUT score (OR = 2.129; 95% CI: 1.077-4.209; p = 0.030), and reduced slow-wave sleep (OR = 5.361; 95% CI: 1.505-19.104; p = 0.010) were factors significantly related to AF. The prevalence of AF in patients with OSA was 6.6%. Age, a history of alcohol consumption, undernutrition, and reduced sleep quality were independent risk factors for the presence of AF in patients with OSA, regardless of the severity of OSA.

[From diabetes to sleep apnea: what obesity complications should we look for?]

The prevalence of obesity has increased worldwide. For Germany, according to the "Study on Adult Health in Germany" (DEGS1) of the Robert Koch Institute from the years 2008-2011, the prevalence of a BMI ≥25 kg/m² was 67,1% for men and 53,0% for women, whereby the proportion of obesity, i.e. a BMI ≥30 kg/m² is 23, 3% for men and 23,9% for women. Compared to 1998, the prevalence of obesity in the same group was 18, 8% for men and 21,7% for women. Because of the increasing prevalence of overweight and obesity, the number of patients with obesity-associated comorbidities is correspondingly increasing. There is a close association between obesity and an increased risk of metabolic diseases, cardiovascular diseases, but also musculoskeletal diseases, some types of cancer and mental comorbidities. In addition, obesity might also lead to restrictions in activities of daily living, reduced quality of life, unemployment and early retirement. A knowledge of obesity-associated sequelae is therefore essential in order to specifically look for them, treat them and thereby improve patient care and ultimately morbidity and mortality of patients with obesity.

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.

Association of Types of Sleep Apnea and Nocturnal Hypoxemia with Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy

BACKGROUND

Data regarding the association between sleep apnea (SA) and atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) are still limited. We aim to investigate the association of both types of SA, obstructive sleep apnea (OSA) and central sleep apnea (CSA), and nocturnal hypoxemia with AF in HCM.

METHODS

A total of 606 patients with HCM who underwent sleep evaluations were included. Logistic regression was used to assess the association between sleep disorder and AF.

RESULTS

SA was presented in 363 (59.9%) patients, of whom 337 (55.6%) had OSA and 26 (4.3%) had CSA. Patients with SA were older, more often male, had a higher body mass index, and more clinical comorbidities. Prevalence of AF was higher in patients with CSA than patients with OSA and without SA (50.0% versus 24.9% and 12.8%, p < 0.001). After adjustment for age, sex, body mass index, hypertension, diabetes mellitus, cigarette use, New York Heart Association class and severity of mitral regurgitation, SA (OR, 1.79; 95% CI, 1.09-2.94) and nocturnal hypoxemia (higher tertile of percentage of total sleep time with oxygen saturation < 90% [OR, 1.81; 95% CI, 1.05-3.12] compared with lower tertile) were significantly associated with AF. The association was much stronger in the CSA group (OR, 3.98; 95% CI, 1.56-10.13) than in OSA group (OR, 1.66; 95% CI, 1.01-2.76). Similar associations were observed when analyses were restricted to persistent/permanent AF.

CONCLUSION

Both types of SA and nocturnal hypoxemia were independently associated with AF. Attention should be paid to the screening of both types of SA in the management of AF in HCM.

Clinical and Structural Factors Affecting Ablation Outcomes in Atrial Fibrillation Patients - A Review

Catheter ablation is an effective and durable treatment option for patients with atrial fibrillation (AF). Ablation outcomes vary widely, with optimal results in patients with paroxysmal AF and diminishing results in patients with persistent or long-standing persistent AF. A number of clinical factors including obesity, hypertension, diabetes, obstructive sleep apnea, and alcohol use contribute to AF recurrence following ablation, likely through modulation of the atrial electroanatomic substrate. In this article, we review the clinical risk factors and the electro-anatomic features that contribute to AF recurrence in patients undergoing ablation for AF.

Obesity as a risk factor for cardiac arrhythmias

Obesity is global health problem with an estimated three billion people worldwide being classified as overweight or obese. In addition to being associated with a range of adverse health outcomes, obesity is linked to higher risks of atrial and ventricular arrhythmias, as well as sudden cardiac death. Obesity is a multifactorial disease that often co-exists with hypertension, diabetes, and sleep apnoea, which are also independent risk factors for cardiac arrhythmias. Nevertheless, compelling evidence suggests that increasing adiposity is an independent proarrhythmic risk factor and that weight loss can be a mitigating and preventative intervention to reduce arrhythmia incidence. This review briefly outlines the economic and social burden of obesity and summarises evidence for the direct and indirect effects of increasing adiposity on risk of atrial and ventricular arrhythmias. The paper also summarises the evidence for electrocardiographic changes indicative of obesity-related atrial and ventricular remodelling and how weight reduction and management of comorbidity might reduce arrhythmic burden.

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.

Effect of Widespread Sleep Apnea Screening on Progression of Atrial Fibrillation

Sleep apnea (SA) is recognized as a predictor of incident atrial fibrillation (AF) and AF recurrence after treatment. However, data on the prevalence of SA phenotypes in patients with AF and the effect of widespread SA screening on AF outcomes are scarce. We conducted a retrospective study of patients with AF referred for SA testing between March 2018 and April 2020. The screening was performed using home sleep testing or polysomnography. AF outcomes were examined by assessment of AF progression as defined by a change from paroxysmal AF to persistent AF, change in antiarrhythmic drug, having an ablation or cardioversion. Of 321 patients evaluated for AF, 251 patients (78%) completed SA testing. A total of 185 patients with complete follow-up data and SA testing were included in our analysis: 172 patients (93%) had SA; 90 of those (49%) had primarily obstructive sleep apnea, 77 patients (42%) had mixed apnea, and 5 patients (3%) had pure central apnea. Time from AF diagnosis to SA testing was associated with AF progression; after 2 years, the risk of AF progression increased (p <0.008). Continuous positive airway pressure treatment did not affect AF progression (p = 0.99). In conclusion, SA is highly prevalent in an unselected population of patients with AF, with mixed apnea being present in over 40% of the population. Early SA testing was associated with decreased rates of AF progression, likely because of earlier and potentially more aggressive pursuit of rhythm control.

Impact of Desaturation Patterns versus Apnea-Hypopnea Index in the Development of Cardiovascular Comorbidities in Obstructive Sleep Apnea Patients

Various phenotypes of obstructive sleep apnea (OSA) have been recently described and are poorly assessed by the commonly used polysomnographic indices, such as the apnea-hypopnea index and oxygen desaturation index. Nocturnal hypoxemia is the hallmark of OSA and new quantitative markers, as hypoxic burden or desaturation severity, have been shown to be associated with cardiovascular (CV) mortality. The purpose of this overview is to review the endophenotypical and clinical characteristics of OSA, the current metrics, and to analyze different measurements of hypoxemia in OSA to predict the cardiovascular impact (eg hypoxic burden). Potential interest of multidimensional models to classify OSA, such as BAVENO classification, is also discussed, with the goal of focusing on specific endophenotypes that are likely to develop CV comorbidities, in order to guide clinicians to more aggressive management of OSA in these individuals.

Intermittent Hypoxia and Atherosclerosis: From Molecular Mechanisms to the Therapeutic Treatment

Intermittent hypoxia (IH) has a dual nature. On the one hand, chronic IH (CIH) is an important pathologic feature of obstructive sleep apnea (OSA) syndrome (OSAS), and many studies have confirmed that OSA-related CIH (OSA-CIH) has atherogenic effects involving complex and interacting mechanisms. Limited preventive and treatment methods are currently available for this condition. On the other hand, non-OSA-related IH has beneficial or detrimental effects on the body, depending on the degree, duration, and cyclic cycle of hypoxia. It includes two main states: intermittent hypoxia in a simulated plateau environment and intermittent hypoxia in a normobaric environment. In this paper, we compare the two types of IH and summarizes the pathologic mechanisms and research advances in the treatment of OSA-CIH-induced atherosclerosis (AS), to provide evidence for the systematic prevention and treatment of OSAS-related AS.

Methodology for the nocturnal cardiac arrhythmia ancillary study of the ADVENT-HF trial in patients with heart failure with reduced ejection fraction and sleep-disordered breathing

Background

Sleep disordered breathing (SDB) may trigger nocturnal cardiac arrhythmias (NCA) in patients with heart failure with reduced ejection fraction (HFrEF). The NCA ancillary study of the ADVENT-HF trial will test whether, in HFrEF-patients with SDB, peak-flow-triggered adaptive servo-ventilation (ASVpf) reduces NCA. To this end, accurate scoring of NCA from polysomnography (PSG) is required.

Objective

To develop a method to detect NCA accurately from a single-lead electrocardiogram (ECG) recorded during PSG and assess inter-observer agreement for NCA detection.

Methods

Quality assurance of ECG analysis included training of the investigators, development of standardized technical quality, guideline-conforming semi-automated NCA-scoring via Holter-ECG software and implementation of an arrhythmia adjudication committee. To assess inter-observer agreement, the ECG was analysed by two independent investigators and compared for agreement on premature ventricular complexes (PVC) /h, premature atrial complexes/h (PAC) as well as for other NCA in 62 patients from two centers of the ADVENT-HF trial.

Results

The intraclass correlation coefficients for PVC/h and PAC/h were excellent: 0.99 (95%- confidence interval [CI]: 0.99-0.99) and 0.99 (95%-CI: 0.97-0.99), respectively. No clinically relevant difference in inter-observer classification of other NCA was found. The detection of non-sustained ventricular tachycardia (18% versus 19%) and atrial fibrillation (10% versus 11%) was similar between the two investigators. No sustained ventricular tachycardia was detected.

Conclusion

These findings indicate that our methods are very reliable for scoring NCAs and are adequate to apply for the entire PSG data set of the ADVENT-HF trial.

Effects of Adaptive Servo-Ventilation on Nocturnal Ventricular Arrhythmia in Heart Failure Patients With Reduced Ejection Fraction and Central Sleep Apnea–An Analysis From the SERVE-HF Major Substudy

Background

The SERVE-HF trial investigated the effect of treating central sleep apnoea (CSA) with adaptive servo-ventilation (ASV) in patients with heart failure with reduced ejection fraction (HFrEF).

Objective

The aim of the present ancillary analysis of the SERVE-HF major substudy (NCT01164592) was to assess the effects of ASV on the burden of nocturnal ventricular arrhythmias as one possible mechanism for sudden cardiac death in ASV-treated patients with HFrEF and CSA.

Methods

Three hundred twelve patients were randomized in the SERVE-HF major substudy [no treatment of CSA (control) vs. ASV]. Polysomnography including nocturnal ECG fulfilling technical requirements was performed at baseline, and at 3 and 12 months. Premature ventricular complexes (events/h of total recording time) and non-sustained ventricular tachycardia were assessed. Linear mixed models and generalized linear mixed models were used to analyse differences between the control and ASV groups, and changes over time.

Results

From baseline to 3- and 12-month follow-up, respectively, the number of premature ventricular complexes (control: median 19.7, 19.0 and 19.0; ASV: 29.1, 29.0 and 26.0 events/h; p = 0.800) and the occurrence of ≥1 non-sustained ventricular tachycardia/night (control: 18, 25, and 18% of patients; ASV: 24, 16, and 24% of patients; p = 0.095) were similar in the control and ASV groups.

Conclusion

Addition of ASV to guideline-based medical management had no significant effect on nocturnal ventricular ectopy or tachyarrhythmia over a period of 12 months in alive patients with HFrEF and CSA. Findings do not further support the hypothesis that ASV may lead to sudden cardiac death by triggering ventricular tachyarrhythmia.

Relationship between Severity and Complexity of Coronary Artery Involvement and Obstructive Sleep Apnea Based on STOP-BANG Questionnaire

Background:

Obstructive sleep apnea (OSA), which has a known correlation with cardiovascular disease, is a possible risk factor of coronary artery disease (CAD) that is preventable.

Aims:

We sought to put lights on the relationship between OSA based on the STOP-BANG questionnaire (SBQ) and the severity and complexity of coronary artery involvement.

Methods:

This cross-sectional, single-center, retrospective study was conducted among 145 patients who underwent selective coronary angiography (SCA) between October 2018 and March 2019, admitted to the Tehran Heart Center, Tehran, Iran. OSA risk was assessed in patients based on SBQ categories. Also, the severity and complexity of coronary artery involvement calculated according to SYNTAX and Gensini scores. Analysis performed by statistical software SPSS 25.

Results:

Based on SBQ risk assessment categories, 22 (15.2%), 64 (44.1%), and 59 (40.7%) of the patients were low, intermediate, and high-risk for OSA, respectively. By comparing the means of coronary artery involvement, there was no significant difference in SYNTAX score 17.15 ± 13.67 (10.56–23.74) in low, 15.67 ± 9.78 (13.19–18.16) in intermediate, and 16.93 ± 9.21 (14.42–19.45) in high-risk groups; P value: 0.754, and Gensini score 66.4 ± 70.75 (35.04–97.77) in low, 66.21 ± 55.05 (52.45–79.96) in intermediate, 74.61 ± 56.33 (59.93–89.3) iin high risk groups; P value: 0.697 with groups of OSA risks. Also, after adjusting confounding factors, there was still no statistically significant difference in terms of coronary involvement scores.

Conclusions:

There was no statistically significant difference in SYNTAX and Gensini scores of different groups of OSA risk categories based on the SBQ. However, our results can't be extended into the connection between OSA and CAD.

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.

Research Opportunities in Autonomic Neural Mechanisms of Cardiopulmonary Regulation: A Report From the National Heart, Lung, and Blood Institute and the National Institutes of Health Office of the Director Workshop

This virtual workshop was convened by the National Heart, Lung, and Blood Institute, in partnership with the Office of Strategic Coordination of the Office of the National Institutes of Health Director, and held September 2 to 3, 2020. The intent was to assemble a multidisciplinary group of experts in basic, translational, and clinical research in neuroscience and cardiopulmonary disorders to identify knowledge gaps, guide future research efforts, and foster multidisciplinary collaborations pertaining to autonomic neural mechanisms of cardiopulmonary regulation. The group critically evaluated the current state of knowledge of the roles that the autonomic nervous system plays in regulation of cardiopulmonary function in health and in pathophysiology of arrhythmias, heart failure, sleep and circadian dysfunction, and breathing disorders. Opportunities to leverage the Common Fund's SPARC (Stimulating Peripheral Activity to Relieve Conditions) program were characterized as related to nonpharmacologic neuromodulation and device-based therapies. Common themes discussed include knowledge gaps, research priorities, and approaches to develop novel predictive markers of autonomic dysfunction. Approaches to precisely target neural pathophysiological mechanisms to herald new therapies for arrhythmias, heart failure, sleep and circadian rhythm physiology, and breathing disorders were also detailed.

Obstructive Sleep Apnea and Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a chronic sleep disorder more common in older men. It has been shown that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is significantly underdiagnosed. This review, including 54,271 patients, carried out a meta-analysis to investigate the association between OSA and AF. We also performed a meta-regression to explore cofactors influencing this correlation. A strong link was found between these two disorders. The incidence of AF is 88% higher in patients with OSA. Age and hypertension independently strengthened this association, indicating that OSA treatment could help reduce AF recurrence. Further research is needed to confirm these findings. Atrial Fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a regulatory respiratory disorder of partial or complete collapse of the upper airways during sleep leading to recurrent pauses in breathing. OSA is more common in older men. Evidence exists that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is underdiagnosed. In order to investigate the incidence of AF in OSA patients, we carried out a meta-analysis including 20 scientific studies with a total of 54,271 subjects. AF was present in 4801 patients of whom 2203 (45.9%) had OSA and 2598 (54.1%) did not. Of a total of 21,074 patients with OSA, 2203 (10.5%) had AF and 18,871 (89.5%) did not. The incidence of AF was 88% higher in patients with OSA. We performed a meta-regression to explore interacting factors potentially influencing the occurrence of AF in OSA. Older age and hypertension independently strengthened this association. The clinical significance of our results is that patients with OSA should be referred early to the cardiologist. Further research is needed for the definition of the mechanisms of association between AF and OSA.

Obstructive Sleep apnea and cardiovascular events in Elderly Patients

INTRODUCTION

In recent decades, life expectancy has increased considerably. The cardiovascular effects of Obstructive Sleep Apnea (OSA) in the elderly lead to patient disability and high resource consumption. Intermittent nocturnal hypoxia leads to hemodynamic stress and adrenergic activation, which promotes cardiovascular disease. However, chronic intermittent hypoxia may protect elderly patients from cardiovascular events (CVE) due to biological adaptation.

AREAS COVERED

OSA patients are at increased risk of cardiovascular events. The severity of OSA increases cardiovascular risk, and this association also exists in the elderly. This article reviews the association between OSA, CPAP treatment, and CVE, particularly stroke and coronary heart disease (CHD), in the elderly. MEDLINE and the Cochrane Collaboration databases were searched from inception to July 2021.

EXPERT COMMENTARY

Although a positive association between OSA and the incidence of cardiovascular disease in the elderly has been established, the role of sleep apnea in certain cardiovascular events remains controversial. Most authors agree that untreated OSA is a risk factor for stroke or worse stroke prognosis. However, the association between OSA and CHD is usually less pronounced than between OSA and stroke, especially in the elderly.

Sleep Disordered Breathing, Obesity and Atrial Fibrillation: A Mendelian Randomisation Study

It remains unclear whether the association between obstructive sleep apnoea (OSA), a form of sleep-disordered breathing (SDB), and atrial fibrillation (AF) is causal or mediated by shared co-morbidities such as obesity. Existing observational studies are conflicting and limited by confounding and reverse causality. We performed Mendelian randomisation (MR) to investigate the causal relationships between SDB, body mass index (BMI) and AF. Single-nucleotide polymorphisms associated with SDB (n = 29) and BMI (n = 453) were selected as instrumental variables to investigate the effects of SDB and BMI on AF, using genetic association data on 55,114 AF cases and 482,295 controls. Primary analysis was conducted using inverse-variance weighted MR. Higher genetically predicted SDB and BMI were associated with increased risk of AF (OR per log OR increase in snoring liability 2.09 (95% CI 1.10-3.98), p = 0.03; OR per 1-SD increase in BMI 1.33 (95% CI 1.24-1.42), p < 0.001). The association between SDB and AF was not observed in sensitivity analyses, whilst associations between BMI and AF remained consistent. Similarly, in multivariable MR, SDB was not associated with AF after adjusting for BMI (OR 0.68 (95% CI 0.42-1.10), p = 0.12). Higher BMI remained associated with increased risk of AF after adjusting for OSA (OR 1.40 (95% CI 1.30-1.51), p < 0.001). Elevated BMI appears causal for AF, independent of SDB. Our data suggest that the association between SDB, in general, and AF is attributable to mediation or confounding from obesity, though we cannot exclude that more severe SDB phenotypes (i.e., OSA) are causal for AF.

Obstructive sleep apnea and stroke: The mechanisms, the randomized trials, and the road ahead

When considered separately from cardiovascular disease, stroke is the third leading cause of death in the U.S. and is the leading cause of long-term disability in adults. New approaches that can be offered to the majority of ischemic stroke patients, can be continued throughout post-stroke care, can limit stroke severity, and can complement or even enhance rehabilitation, would transform ischemic stroke recovery. The treatment of obstructive sleep apnea (OSA) in patients with acute ischemic stroke may represent one such approach. This manuscript reviews the epidemiologic studies of the bidirectional association between OSA and stroke, and the mechanisms and molecular signatures of OSA leading to transient ischemic attack and stroke as well as the randomized controlled trials and observational cohort studies examining continuous positive airway treatment efficacy on the impact of stroke outcomes. Finally, the insights these studies provide on future research are also discussed.

Obstructive Sleep Apnea Syndrome Phenotyping by Cluster Analysis: Typical Sleepy, Obese Middle-aged Men with Desaturating Events are A Minority of Patients in A Multi-ethnic Cohort of 33% Women

OBJECTIVE

Several clinical obstructive sleep apnea syndrome (OSAS) phenotypes associated with heterogeneous cardiovascular risk profiles have been recently identified. The purpose of this study was to identify clusters amongst these profiles that allow for the differentiation of patients.

METHODS

This retrospective study included all moderate-to-severe OSAS patients referred to the sleep unit over a 5-year period. Demographic, symptom, comorbidity, polysomnographic, and continuous positive airway pressure (CPAP) adherence data were collected. Statistical analyses were performed to identify clusters of patients.

RESULTS

A total of 567 patients were included (67% men, 54±13 years, body mass index: 32±7 kg/m², 65% Caucasian, 32% European African). Five clusters were identified: less severe OSAS (n=172); healthier severe OSAS (n=160); poorly sleeping OSAS patients with cardiometabolic comorbidities (n=87); younger obese men with sleepiness at the wheel (n=94); sleepy obese men with very severe desaturating OSAS and cardiometabolic comorbidities (n=54). Patients in clusters 3 and 5 were older than those in clusters 2 and 4 (P=0.034). Patients in clusters 4 and 5 were significantly more obese than those in the other clusters (P=0.04). No significant differences were detected in terms of symptoms and comorbidities. Polysomnographic profiles were very discriminating between clusters. CPAP adherence was similar in all clusters but, among adherent patients, daily usage was more important in cluster 1 (less severe patients) than in cluster 5.

CONCLUSION

This study highlights that the typical sleepy obese middle-aged men with desaturating events represent only a minority of patients in our multi-ethnic moderate-to-severe OSAS cohort of 33% females.

Ventricular arrhythmia in heart failure patients with reduced ejection fraction and central sleep apnoea

Cheyne–Stokes respiration (CSR) may trigger ventricular arrhythmia in patients with heart failure with reduced ejection fraction (HFrEF) and central sleep apnoea (CSA). This study determined the prevalence and predictors of a high nocturnal ventricular arrhythmia burden in patients with HFrEF and CSA (with and without CSR) and to evaluate the temporal association between CSR and the ventricular arrhythmia burden.

 This cross-sectional ancillary analysis included 239 participants from the SERVE-HF major sub-study who had HFrEF and CSA, and nocturnal ECG from polysomnography. CSR was stratified in ≥20% and <20% of total recording time (TRT). High burden of ventricular arrhythmia was defined as >30 premature ventricular complexes (PVCs) per hour of TRT. A sub-analysis was performed to evaluate the temporal association between CSR and ventricular arrhythmias in sleep stage N2.

 High ventricular arrhythmia burden was observed in 44% of patients. In multivariate logistic regression analysis, male sex, lower systolic blood pressure, non-use of antiarrhythmic medication and CSR ≥20% were significantly associated with PVCs >30·h⁻¹ (OR 5.49, 95% CI 1.51–19.91, p=0.010; OR 0.98, 95% CI 0.97–1.00, p=0.017; OR 5.02, 95% CI 1.51–19.91, p=0.001; and OR 2.22, 95% CI 1.22–4.05, p=0.009; respectively). PVCs occurred more frequently during sleep phases with versus without CSR (median (interquartile range): 64.6 (24.8–145.7) versus 34.6 (4.8–75.2)·h⁻¹ N2 sleep; p=0.006).

 Further mechanistic studies and arrhythmia analysis of major randomised trials evaluating the effect of treating CSR on ventricular arrhythmia burden and arrhythmia-related outcomes are warranted to understand how these data match with the results of the parent SERVE-HF study.

High ventricular arrhythmia burden occurs in 44% of heart failure patients with reduced ejection fraction and central sleep apnoea. Arrhythmia burden is higher in sleep phases with versus without Cheyne–Stokes respiration.https://bit.ly/2QBDamC

Cross-ethnic comparison of the association between central sleep apnea and atrial fibrillation/flutter: The Kuakini Honolulu-Asia Aging Study and the Osteoporotic Fractures in Men (Mr.OS) study

Introduction

Few studies indicated the impact of ethnicity on an association between central sleep apnea (CSA) and atrial fibrillation/flutter (AF) in older populations. We assessed possible ethnic differences in the association among elderly Japanese-American and White-American men.

Methods

We performed a cross-sectional analysis using two population studies of Japanese-American and White-American men. The Kuakini Honolulu-Asia Aging Study is a longitudinal cohort study of Japanese-American men living in Hawaii. Sleep data were collected between 1999 and 2000. The Osteoporotic Fractures in Men (Mr.OS) Sleep Study was conducted between 2003 and 2005 on the continental U.S. The majority of Mr.OS participants were White-American. We selected 79-90 year old males, who had overnight polysomnography from both studies. Total participants were 690 Japanese-American and 871 White-American men. The central apnea index (CAI) was the measure of the number of central apneas. CSA was defined by CAI>=5. Cheyne-Stokes breathing (CSB) was defined as a minimum consecutive 5-10 min period of a crescendo-decrescendo respiratory pattern associated with CSA.

Results

The prevalence of AF was 5.7% in Japanese-American men and 9.0% in White-American men. The prevalence of CSA and CSB in White-Americans were higher than in Japanese-Americans (11.5% vs 6.5% and 5.7% vs 3.3%, respectively). In multivariable-adjusted logistic regression models, CSA was associated with higher odds of AF, and the association was stronger in Japanese-Americans [Odds Ratio (OR) = 4.77, 95% confidence interval (CI): 1.95-11.67] than in White-Americans (OR = 2.09, 95 %CI: 1.09-4.01). CSB showed similar trends as CSA.

Conclusions

After adjustment, CSA and CSB were significantly associated with AF in both Japanese-American and White-American men.

Orofacial Myofunctional Therapy in Obstructive Sleep Apnea Syndrome: A Pathophysiological Perspective

Obstructive sleep apnea (OSA) syndrome is a multi-factorial disorder. Recently identified pathophysiological contributing factors include airway collapsibility, poor pharyngeal muscle responsiveness, a low arousal threshold, and a high loop gain. Understanding the pathophysiology is of pivotal importance to select the most effective treatment option. It is well documented that conventional treatments (continuous positive airway pressure (CPAP), upper airway surgery, and dental appliance) may not always be successful in the presence of non-anatomical traits, especially in mild to moderate OSA. Orofacial myofunctional therapy (OMT) consists of isotonic and isometric exercises targeted to oral and oropharyngeal structures, with the aim of increasing muscle tone, endurance, and coordinated movements of pharyngeal and peripharyngeal muscles. Recent studies have demonstrated the efficacy of OMT in reducing snoring, apnea-hypopnea index, and daytime sleepiness, and improving oxygen saturations and sleep quality. Myofunctional therapy helps to reposition the tongue, improve nasal breathing, and increase muscle tone in pediatric and adult OSA patients. Studies have shown that OMT prevents residual OSA in children after adenotonsillectomy and helps adherence in CPAP-treated OSA patients. Randomized multi-institutional studies will be necessary in the future to determine the effectiveness of OMT in a single or combined modality targeted approach in the treatment of OSA. In this narrative review, we present up-to-date literature data, focusing on the role of OSA pathophysiology concepts concerning pharyngeal anatomical collapsibility and muscle responsiveness, underlying the response to OMT in OSA patients.

Deep Neck Infection Risk in Patients with Sleep Apnea: Real-World Evidence

(1) Background: Sleep apnea may be a risk factor for deep neck infection (DNI). The objective of this study was to investigate the effects of sleep apnea on DNI. (2) Methods: In this first nationwide retrospective cohort study on the sleep apnea–DNI correlation, we obtained data from the Longitudinal Health Insurance Database 2005, a subset of the Taiwan National Health Insurance Research Database. Patients who were newly diagnosed with sleep apnea between 1997 and 2012 were identified, and patients without sleep apnea were matched at a 1:4 ratio in age, sex, socioeconomic status, and urbanization level. The primary outcome of this study was DNI occurrence. The treatment modalities for sleep apnea and the comorbidities that occurred during the study period were also analyzed. (3) Results: Our sleep apnea and comparison (non-sleep apnea) cohorts comprised 6114 and 24,456 patients, respectively. We compared the cumulative incidence of DNI between these cohorts and found a greater incidence of DNI in the sleep apnea cohort (p < 0.001). A strong sleep apnea–DNI association was found following analysis via the adjusted Cox proportional-hazards model (full model hazard ratio, 1.71; 95% confidence interval, 1.28–2.28; p < 0.001). In the subgroup analysis, sleep apnea increased DNI risk in men, in those aged < 50 years, and in those without diabetes mellitus, end-stage renal disease, liver cirrhosis, autoimmune disease, obesity, tonsillectomy, or adenotonsillectomy. (4) Conclusions: Our results confirmed sleep apnea to be an independent risk factor for DNI. Physicians should be aware of the potential occurrence of DNI in patients with sleep apnea.

Central sleep apnea and atrial fibrillation: A review on pathophysiological mechanisms and therapeutic implications

Precipitating factors and chronic diseases associated with atrial fibrillation (AF) are detailed in the literature. Emerging evidence over the last several decades suggests a potential causal relationship between central sleep apnea (CSA) and AF. Mechanisms including apnea-induced hypoxia with intermittent arousal, fluctuating levels of carbon dioxide, enhanced sympathetic/neurohormonal activation and oxidative stress causing inflammation have been implicated as etiologic causes of AF within this subpopulation. CSA affects the efficacy of pharmacologic and catheter-based antiarrhythmic treatments, which is why treating CSA prior to these interventions may lead to lower rates of AF. Subsequently, a reduction in the AF burden with transvenous phrenic nerve stimulation (TPNS) has become a topic of interest. The present review describes the relationship between these conditions, pathophysiologic mechanisms implicating the role of CSA in development of AF, and emerging therapeutic interventions.

Diagnosed Sleep Apnea and Cardiovascular Disease in Atrial Fibrillation Patients: The Role of Measurement Error from Administrative Data

BACKGROUND

Atrial fibrillation and obstructive sleep apnea are common conditions, but little is known about obstructive sleep apnea and cardiovascular risk among atrial fibrillation patients.

METHODS

Using the Truven Health MarketScan databases, we constructed a prospective cohort of atrial fibrillation patients from 2007 to 2014. Atrial fibrillation, obstructive sleep apnea, stroke, myocardial infarction, and confounders were defined using the International Classification of Disease-9-CM codes. We matched individuals with an obstructive sleep apnea diagnosis with up to five individuals without a diagnosis by age, sex, and enrollment date. Cox proportional hazards models adjusted for confounders and high-dimensional propensity scores. We included migraines as a control outcome. Bias analysis used published sensitivities and specificities to generate rate ratios adjusted for obstructive sleep apnea misclassification.

RESULTS

We matched 56,969 individuals with an obstructive sleep apnea diagnosis to 323,246 without. During a mean follow-up of 16 months, 3234 incident strokes and 4639 incident myocardial infarctions occurred. After adjustment, obstructive sleep apnea diagnosis was strongly associated with reduced risk of incident stroke (hazard ratio = 0.48, 95% confidence interval = 0.43, 0.53) and myocardial infarction (0.40, [0.37, 0.44]) and a smaller reduced risk of migraines (0.82, [0.68, 0.99]). Bias analysis produced wide-ranging or inestimable rate ratios adjusted for misclassification of obstructive sleep apnea.

CONCLUSIONS

Obstructive sleep apnea diagnosis in atrial fibrillation patients was strongly associated with reduced risk of incident cardiovascular disease. We discuss misclassification, selection bias, and residual confounding as potential explanations.

Comparison of clinical and polysomnographic parameters between obese and nonobese obstructive sleep apnea

Introduction:

Obstructive sleep apnea (OSA) is one of the most common sleep-disordered breathing characterized by repeated cessation or reduction in airflow during sleep. OSA occurs in both obese and nonobese individual. This study was designed to compare the clinical and polysomnographic data between obese and nonobese patients with OSA.

Materials and Methods:

This was a retrospective study that included all the patients diagnosed as between November 2013 and December 2014. The patients were classified into nonobese (n = 23) and obese (n = 72) groups if their body mass index (BMI) was <27.5 and ≥27.5, respectively. Data were analyzed using Statistical Package for the Social Sciences (SPSS) software program, version 20.0 (SPSS, Chicago, Illinois). A value of P < 0.05 was considered statistically significant.

Results:

There were 95 patients of OSA, of which 23 (44.4%) were nonobese and 72 (75.78%) were obese with a mean BMI of 24.37 ± 3.09 and 34.27 ± 8.34 kg/m², respectively. Characteristics, such as male predominance, higher BMI, neck circumference, and loud snoring, were significantly higher in obese group (P < 0.05) as compared to nonobese. Mild OSA (AHI 5-15) was significantly higher in nonobese patients (39.13% vs. 5.55%, P < 0.00001), whereas severe OSA (AHI >30) was higher in obese patients as compared with nonobese (66.66% vs. 30.43%, P = 0.002). When comparing comorbidities, the hypertension was significantly higher in the obese (47.22% vs. 13.04%, P = 0.003) than the nonobese patients. The incidence of diabetes (37.50% vs. 17.39%) and hypothyroidism (16.66% vs. 4.34%) was also higher in obese group as compared with nonobese. No significant difference was found for mean age, racial origin (Asian/African), and ESS score between obese and nonobese patients.

Conclusion:

Obstructive sleep apnoea is not restricted to only obese individual; rather it also occurs in nonobese. The severity of OSA in nonobese has generally less as compared with obese and its early identification required high index of suspicion.

Individual periodic limb movements with arousal are temporally associated with nonsustained ventricular tachycardia: a case-crossover analysis

STUDY OBJECTIVES

Both periodic limb movements during sleep (PLMS) and arousals are associated with sympathetic nervous system activation and may be arrhythmogenic. We hypothesize a temporal relationship exists between individual PLMS, particularly with arousal, and nonsustained ventricular tachycardia (NSVT) events.

METHODS

A bidirectional time-stratified case-crossover design was used to assess temporal associations between PLMS and NSVT during sleep in 49 Osteoporotic Fractures in Men Sleep Study participants with NSVT in a community-based cohort (n = 2,911). Sleep time was divided into approximate 30-min segments. For each NSVT (n = 141), we selected a preceding 30-s hazard period and three randomly chosen 30-s control periods from sleep within the same segment and evaluated for PLMS, respiratory events, minimum saturation, and arousals. Odds ratios and 95% confidence intervals-OR (95% CI)-were determined by conditional logistic regression; covariates included EEG arousals, minimum saturation, and respiratory events in the same hazard/control period.

RESULTS

Participants with NSVT were 79.5 ± 6.2 years with a PLMS index of 32.1 (IQR: 10.1, 61.4) and apnea-hypopnea index of 17.1 (IQR: 9.4, 26.1). PLMS without arousal were not significantly associated with NSVT (OR = 0.80, 95% CI: 0.41-1.59). PLMS with arousal were associated with NSVT in unadjusted analyses (OR = 2.50, 95% CI: 1.11-5.65) and after adjustment (OR = 2.31, 95% CI: 1.02-5.25). Arousals associated with PLMS were associated with NSVT in unadjusted (OR = 2.84, 95% CI: 1.23-6.56) and adjusted analyses (OR = 2.61, 95% CI: 1.13-6.05).

CONCLUSIONS

PLMS with (but not without) arousals are temporally associated with a greater than twofold higher odds of subsequent NSVT episodes. PLMS-related arousals may be physiologically important ventricular arrhythmia triggers.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT00070681.

Association between central sleep apnea and atrial fibrillation/flutter in Japanese-American men: The Kuakini Honolulu Heart Program (HHP) and Honolulu-Asia Aging Study (HAAS)

INTRODUCTION

While several studies have indicated that central sleep apnea (CSA) is associated with atrial fibrillation and atrial flutter (AF) in older populations, few studies have focused on older Asian populations.

METHODS

We conducted a cross- sectional analysis using data from the 1999-2000, 7th exam cycle of the Kuakini Honolulu-Asia Aging Study. Participants were 718 Japanese-American men between 79 and 97 years old, who had overnight polysomnography. Obstructive Apnea-Hypopnea Index (OAHI) was the measure of the number of obstructive apneas and hypopneas with >4% oxygen desaturation. Additionally, the Central Apnea Index (CAI) was the measure of the number of central apneas. Obstructive sleep apnea (OSA) was categorized as none (OAHI <5), mild (OAHI 5-14), moderate (OAHI 15-29) and severe (OAHI ≥30). CSA was defined by CAI of 5 or more. Cheyne-Stokes Breathing (CSB) was defined as a minimum consecutive 5-minute period of a crescendo-decrescendo respiratory pattern associated with CSA.

RESULTS

AF prevalence was 5.5% (39 of 709). The prevalence proportions of severe OSA, CSA, and CSB were 20.2% (143 of 709), 6.4% (43 of 673) and 3.2% (22 of 673), respectively. In multivariable-adjusted logistic regression models, CSA and CSB were significantly associated with AF prevalence: odds ratio (OR) 5.15, 95% confidential interval (CI), 2.21-12.52 and OR 6.26, 95% CI, 2.05-19.14, respectively. However, OSA was not significantly associated with AF prevalence.

CONCLUSION

AF prevalence is associated with CSA and CSB but not OSA in older Japanese-American men. This information could help target AF prevention strategies in this population.

Fentanyl-Induced Block of hERG Channels Is Exacerbated by Hypoxia, Hypokalemia, Alkalosis, and the Presence of hERG1b

Human ether-a-go-go-related gene (hERG) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium current (I_Kr) important for repolarization of cardiac action potentials. Drug-induced disruption of hERG channel function is a main cause of acquired long QT syndrome, which can lead to ventricular arrhythmias and sudden death. Illicit fentanyl use is associated with sudden death. We have demonstrated that fentanyl blocks hERG current (I_hERG) at concentrations that overlap with the upper range of postmortem blood concentrations in fentanyl-related deaths. Since fentanyl can cause respiratory depression and electrolyte imbalances, in the present study we investigated whether certain pathologic circumstances exacerbate fentanyl-induced block of I_hERG Our results show that chronic hypoxia or hypokalemia additively reduced I_hERG with fentanyl. As well, high pH potentiated the fentanyl-mediated block of hERG channels, with an IC₅₀ at pH 8.4 being 7-fold lower than that at pH 7.4. Furthermore, although the full-length hERG variant, hERG1a, has been widely used to study hERG channels, coexpression with the short variant, hERG1b (which does not produce current when expressed alone), produces functional hERG1a/1b channels, which gate more closely resembling native I_Kr Our results showed that fentanyl blocked hERG1a/1b channels with a 3-fold greater potency than hERG1a channels. Thus, in addition to a greater susceptibility due to the presence of hERG1b in the human heart, hERG channel block by fentanyl can be exacerbated by certain conditions, such as hypoxia, hypokalemia, or alkalosis, which may increase the risk of fentanyl-induced ventricular arrhythmias and sudden death. SIGNIFICANCE STATEMENT: This work demonstrates that heterologously expressed human ether a-go-go-related gene (hERG) 1a/1b channels, which more closely resemble rapidly activating delayed rectifier potassium current in the human heart, are blocked by fentanyl with a 3-fold greater potency than the previously studied hERG1a expressed alone. Additionally, chronic hypoxia, hypokalemia, and alkalosis can increase the block of hERG current by fentanyl, potentially increasing the risk of cardiac arrhythmias and sudden death.

The impact of continuous positive airway pressure on cardiac arrhythmias in patients with sleep apnea

Background

Obstructive sleep apnea (OSA) can lead to cardiac complications: brady and tachyarrhythmias and sudden cardiac death. Continuous positive airway pressure (CPAP) is the gold standard for the treatment of OSA. The present study aims to demonstrate the efficiency of CPAP in the treatment of cardiac arrhythmias in patients with OSA. The study also recorded the frequency of arrhythmias in patients with untreated OSA and assessed the association between the severity of OSA and the occurrence of arrhythmias.

Materials and Methods

This is a prospective cohort study. Ninety-three patients with OSA were included, aged 60 (58-64) years, with female/male sex ratio of 1:4. They were subjected simultaneously to home respiratory polygraphy examination and Holter electrocardiogram monitoring, in two different stages: at diagnosis and at the 3-month checkup after CPAP treatment. The presence of supraventricular and ventricular arrythmias was noted. Respiratory parameter values were also recorded.

Results

Statistically significant decrease in the occurrence of supraventricular (P < 0.001) and ventricular extrasystoles (P < 0.001), atrial fibrillation (AF) (P = 0.03), nonsustained ventricular tachycardia (NSVT) (P = 0.03), and sinus pauses (P < 0.001) was observed 3 months after treatment with CPAP, compared with baseline. The apnea-hypopnea index (AHI) was correlated with the ventricular extrasystoles (r = 0.273; P = 0.008). The ejection fraction of the left ventricle was inversely correlated with the episodes of NSVT (r = -0.425; P < 0.001). AF was associated with the longest apnea (r = 0.215; P = 0.04). Cardiac activity pauses were correlated with AHI (r = 0.320; P = 0.002), longest apnea (r = 0.345; P = 0.01), and oxygen desaturation index (r = 0.325; P = 0.04).

Conclusion

The prevalence of cardiac arrhythmias in patients with OSA was reduced after 3 months of CPAP therapy. Cardiac arrhythmias were correlated with the severity of OSA.

Environmental Factors as Modulators of the Relationship between Obstructive Sleep Apnea and Lesions in the Circulatory System

Obstructive sleep apnea (OSA) is a growing social problem, particularly in well-developed countries. It has been demonstrated that obstructive sleep apnea is a significant risk factor for cardiovascular diseases, including arterial hypertension, ischemic heart disease, heart failure, rhythm/conduction disturbances, as well as cerebral stroke. The pathophysiology of these diseases is complex and multifactorial. We present the current state of research on behavioral and environmental factors that influence the relationship between OSA and cardiovascular changes. We discuss the relationship between obesity, alcohol, sedatives, environmental tobacco smoke, allergic diseases and environmental pollution on the one hand and OSA on the other. In this context, the environment should be considered as an important modulator of the relationship between OSA and cardiovascular diseases.

Obstructive Sleep Apnoea Syndrome: Continuous Positive Airway Pressure Therapy for Prevention of Cardiovascular Risk

Obstructive sleep apnoea (OSA) syndrome is characterised by the presence of apnoea or obstructive hypopnoea during sleep, accompanied by hypoxia. It is estimated that the syndrome affects approximately 10% of men and 15% of women. Diagnosis and treatment rates have increased in recent years, but the condition remains undiagnosed in a high percentage of patients. Recent evidence suggests that OSA may increase the risk of cardiovascular disease. The relationship between OSA and cardiovascular disease can be explained, at least in part, by the coexistence of cardiovascular risk factors in the two pathologies, such as age, overweight, smoking and sedentary lifestyle. However, OSA has been independently associated with the risk of developing hypertension, cerebrovascular disease, ischaemic heart disease, heart failure and arrhythmias. Clinical trials that have evaluated the efficacy of continuous positive airway pressure (CPAP) treatment in primary and secondary cardiovascular prevention have not demonstrated a significant reduction in the incidence or recurrence of cardiovascular events. This article analyses the relationship between OSA and cardiovascular risk and discusses recent clinical trials on the efficacy of CPAP in primary and secondary cardiovascular prevention.

Cardiometabolic comorbidities in obstructive sleep apnea patients are related to disease severity, nocturnal hypoxemia, and decreased sleep quality

BACKGROUND

Obstructive sleep apnea syndrome (OSA) is currently recognized as an independent risk factor for hypertension, arrhythmia, coronary heart disease, stroke, and metabolic disorders (e.g. diabetes, dyslipidemia). In clinical practice, apnea-hypopnea index (AHI) is the marker used to classify disease severity and guide treatment. However, AHI alone does not sufficiently identify OSA patients at risk for cardiometabolic comorbidities. With this in mind, the aim of this retrospective study was to determine whether some polysomnographic parameters (e.g. apnea-hypopnea duration, sleep structure, nocturnal hypoxemia) are specifically associated with cardiometabolic comorbidities in OSA.

METHODS

In this retrospective study, 1717 patients suffering from moderate/severe OSA were included between 2013 and 2017. Data on demographics, comorbidities, and polysomnographic characteristics were collected and analyzed to identify factors associated with cardiometabolic complications.

RESULTS

The medical files of 1717 patients (68% male) were reviewed. The mean AHI was 43.1 +/- 27.7 with 57.3% of patients suffering from severe OSA, and 52% from at least one cardiovascular comorbidity (CVCo). Diabetes affected 22% of the patients and 27% exhibited dyslipidemia. Patients affected by CVCos were older, and more often women and non-smokers. These patients also had worse sleep quality, and a more marked intermittent/global nocturnal hypoxemia. With regard to diabetes, diabetics were older, more often non-smoker, non-drinker women, and were more obese. These patients also exhibited more severe OSA, especially in non-REM (NREM) sleep, worse sleep quality, and a more marked intermittent/global nocturnal hypoxemia. Dyslipidemia was more frequent in the absence of alcohol consumption, and was associated with OSA severity, decreased sleep quality, and longer AH in REM sleep.

CONCLUSIONS

This study identifies demographic and polysomnographic factors associated with cardiometabolic comorbidities. Patients (especially women) suffering from more severe OSA, longer sleep apneas and hypopneas, worse sleep quality, and marked intermittent/global nocturnal hypoxemia are more likely to develop cardiometabolic comorbidities. This should stimulate clinicians to obtain adequate treatment in this population.

Associations between sleep conditions and body composition states: results of the EPISONO study

BACKGROUND

Evidence suggests anthropometric indicators of obesity are associated with changes in sleep quality and quantity, and the presence of obstructive sleep apnoea (OSA). Investigations including diverse and objective evaluations of sleep and body composition are scarce. We aimed to evaluate the associations between indicators of sleep impairment and body composition states in a sample from a population-based study.

METHODS

Participants of the first follow-up of the EPISONO (São Paulo, Brazil) >50 years were cross-sectionally evaluated. Sleep was assessed through questionnaires, actigraphy, and polysomnography. Body composition was evaluated by bioelectrical impedance analysis. Appendicular skeletal muscle mass adjusted for body mass index defined sarcopenia (men <0.789 and women <0.512). Total body fat defined obesity (men >30% and women >40%). The overlap between both conditions defined sarcopenic obesity (SO). Final results were obtained by multinomial logistic regression analysis.

RESULTS

Three hundred fifty-nine adults [mean (standard deviation) age, 61 (8.8) years; 212 (59.1%) female] were enrolled. Obesity was detected in 22.6% of the sample, sarcopenia in 5.6%, and SO in 16.2%. After controlling for covariates, OSA was associated with SO [odds ratio = 3.14, 95% confidence interval (CI) = 1.49-6.61]. Additionally, nocturnal hypoxaemia was associated with both obesity (adjusted odds ratio = 2.59, 95% CI = 1.49-4.49) and SO (odds ratio = 2.92, 95% CI = 1.39-6.13). Other indicators of poor sleep/sleep disorders were not associated with body composition states.

CONCLUSIONS

Sarcopenic obesity but not obesity alone was associated with OSA. Both obesity and SO but not sarcopenia were associated with nocturnal hypoxaemia. The findings suggest a complex pathophysiologic relationship between adverse body composition states and OSA. Upcoming research on risk factors and therapeutic interventions for OSA should target synchronically the lean and adipose body tissues.