Exploring hypoglossal nerve stimulation therapy for obstructive sleep apnea: A comprehensive review of clinical and physiological upper airway outcomes

Obstructive sleep apnea (OSA) is a chronic disorder characterized by recurrent episodes of upper airway collapse during sleep, which can lead to serious health issues like cardiovascular disease and neurocognitive impairments. While positive airway pressure serves as the standard treatment, intolerance in some individuals necessitates exploration of alternative therapies. Hypoglossal nerve stimulation (HGNS) promises to mitigate OSA morbidity by stimulating the tongue muscles to maintain airway patency. However, its effectiveness varies, prompting research for optimization. This review summarizes the effects of HGNS on upper airway obstruction from human and animal studies. It examines physiological responses including critical closing pressure, maximal airflow, nasal and upper airway resistance, compliance, stiffness, and geometry. Interactions among these parameters and discrepant findings in animal and human studies are explored. Additionally, the review summarizes the impact of HGNS on established OSA metrics, such as the apnea-hypopnea index, oxygen desaturation index, and sleep arousals. Various therapeutic modalities, including selective unilateral or bilateral HGNS, targeted unilateral HGNS, and whole unilateral or bilateral HGNS, are discussed. This review consolidates our understanding of HGNS mechanisms, fostering exploration of under-investigated outcomes and approaches to drive advancements in HGNS therapy.

Patient-reported outcomes with hypoglossal nerve stimulation for treatment of obstructive sleep apnea: a systematic review and meta-analysis

INTRODUCTION

Hypoglossal nerve stimulation (HNS) has recently been introduced as an alternative treatment for patients with OSA. A large number of studies have demonstrated substantial changes in OSA with this therapy by reducing respiratory events and improving symptoms such as daytime sleepiness and quality of life. The objective of this review was to conduct a systematic review and meta-analysis to evaluate patient-reported outcomes and experience with HNS therapy.

METHODS

A systematic literature search of MEDLINE, Cochrane, and Web of Science was performed to identify randomized controlled and observational studies reporting subjective outcomes with different HNS systems in patients with OSA. Abstracts of 406 articles were screened and a subset of 55 articles were reviewed for eligibility. Risk of bias was assessed using the ROBINS-I tool. Meta-analysis using RevMan was performed when > 2 studies were identified that reported data on a specific outcome.

RESULTS

Thirty-four publications reporting data on 3785 patients with a mean follow-up of 11.8 ± 12.2 months were identified and included in the meta-analysis. The analysis revealed a pooled effect of 4.59 points improvement in daytime sleepiness as measured by the ESS questionnaire (Z = 42.82, p < .001), 2.84 points improvement in daytime functioning as measured by the FOSQ score (Z = 28.38, p < .001), and 1.77 points improvement in sleep quality as measured by the PSQI questionnaire (Z = 2.53, p = .010). Patient-reported experience was consistently positive and revealed additional relevant aspects from this perspective.

CONCLUSION

HNS therapy significantly improves quality of life in patients with OSA and reliably produces clinically meaningful effects on daytime sleepiness, daytime functioning, and sleep quality. Treatment regularly meets or exceeds the minimum clinically important differences defined for the respective instruments. Additional research is needed to further investigate effects on quality of life beyond improvements in daytime sleepiness and daytime functioning.

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.

Predictors and consequences of residual apnea during positive airway pressure therapy

STUDY OBJECTIVES

Determine the risk factors for, and consequences of, residual apnea during long-term positive airway pressure (PAP) therapy for obstructive sleep apnea (OSA).

METHODS

A prospective cohort study of 195 subjects after a split-night polysomnogram. Estimation of residual respiratory events on PAP were done by both automated and manual scoring of data in EncoreAnywhere™. Clinical and polysomnographic predictors of residual apnea were estimated.

RESULTS

There were 166 and 101 patients still on PAP at the 3 and 12 months, respectively. Seventy four (44.6%) and 46 (45.5%) had a residual scored respiratory event index-flow (sREI_FLOW) ≥ 15/hour of use and 46 (45.5%) at the 3rd and 12th month, respectively. Treatment phase central apnea hypopnea index (TCAHI), a surrogate of high loop gain, was the main predictor for residual sREI_FLOW (β = 0.345, p: 0.025) at the 3rd and 12th month (β = 0.147, p: 0.020). TCAHI also predicted unstable breathing (U) %. The body mass index (hazard ratio [HR] 1.034, 95% CI 1.008-1.062, p: 0.012) and effective sREI_FLOW>15/hour in the first month (HR 2.477, 95% CI 1.510-4.065, p < 0.001) were the key predictors for drop out of PAP use at the 12th month. Effective sREI_FLOW>15/hour in the first month was also a predictor for median usage duration >4 h for 70% of the night at both the 3rd month (odds ratio [OR] 0.947, 95% CI 0.909-0.986, p: 0.008) and 12th month (OR 0.973, 95% CI 0.951-0.994, p: 0.014).

CONCLUSIONS

Treatment-phase CAHI predicts long-term residual apnea on PAP. High residual disease adversely impacts adherence.

Calidad de vida relacionada con la salud y adhesión terapéutica a la presión positiva continua en la vía aérea (CPAP) en pacientes con apnea obstructiva del sueño (AOS)

Introduction

The benefits of CPAP in patients with obstructive sleep apnea (OSA) are not achieved without therapeutic adherence (TA). The perception of benefit is one of the main predictors of adherence. However, it is unknown whether the impact of CPAP on health-related quality of life (HRQoL) is related to TA.

Objective

1) To evaluate whether changes in HRQoL after initiating CPAP are associated with AT. 2) To analyze the influence of various TA determinants, including baseline HRQoL.

Methods

Prospective observational and longitudinal study on a cohort of patients with moderate-severe OSA and indication of CPAP. Baseline and after-therapy HRQoL were evaluated using the Quebec Sleep Questionnaire (QSQ), as well as other possible AT determinants. A multivariate analysis was performed.

Results

A total of 364 patients (78% men) were included, with mean age of 55 ± 11 years and apnea-hypopnea index of 42 ± 19/hour. 33.3% without TA. There was no association between HRQoL changes after 3 months of CPAP and AT and between QSQ baseline score and AT. A higher ODI4%, a global improvement and social interactions (QSQ), were associated with AT. Baseline anxiety-depressive symptoms, worsening anxiety, and side effects with CPAP were associated with worse AT.

Conclusions

The impact of CPAP on HRQoL with respect to the perception of social interactions seems to condition TA. The basal impact of the disease, in terms of HRQoL, is not associated with AT.

Hypoglossal nerve stimulation versus positive airway pressure therapy for obstructive sleep apnea

Purpose

Hypoglossal nerve stimulation (HNS) has been shown to treat obstructive sleep apnea (OSA) effectively. The aim of this study was to compare HNS with positive airway pressure (PAP) treatment regarding outcome parameters: (1) sleepiness, (2) apnea–hypopnea index (AHI), and (3) effectiveness.

Methods

Propensity score matching with nearest neighbor algorithm was used to compare outcomes of HNS and PAP therapy in a real-world setting. Data were collected at baseline and 12 months after initiating OSA treatment including demographics, Epworth Sleepiness Scale (ESS), AHI, and objective adherence data. To account for overall treatment efficacy, the mean disease alleviation (MDA) was calculated.

Results

Of 227 patients who received treatment consecutively, 126 could be matched 1:1 with regard to age, body mass index, and AHI. After matching, no statistically significant differences between the groups were found. A clinically important symptom improvement was seen at 12 months in both cohorts, though there was a greater difference in ESS improvement in patients treated with HNS (8.0 ± 5.1 points vs. 3.9 ± 6.8 points; p = 0.042). In both groups, mean posttreatment AHI was significantly reduced (HNS: 8.1 ± 6.3/h; PAP: 6.6 ± 8.0/h; p < 0.001). Adherence after 12 months among patients treated with HNS was higher than in those receiving PAP therapy (5.0 ± 2.6 h/night; 4.0 ± 2.1 h/night) but not with statistical significance. Overall effectiveness calculated with the MDA was 59% in patients treated with HNS compared to 51% receiving PAP.

Conclusion

Patients treated with HNS therapy had significantly greater improvements in daytime sleepiness compared to PAP therapy, while the mean reduction of AHI and overall effectiveness were comparable for both treatments.

Trial registration

ClinicalTrial.gov Identifier: NCT03756805.

Can Weight Loss Improve the Cardiovascular Outcomes of Patients with Obesity and Obstructive Sleep Apnea?

Cardiovascular events are the primary cause of mortality in patients with obstructive sleep apnea and obesity. The rising prevalence of obstructive sleep apnea in recent decades has been linked to increasing rates of obesity. Obstructive sleep apnea has also been linked with many different cardiovascular diseases including coronary artery disease, stroke, heart failure, hypertension, and atrial fibrillation. Obesity is an increasing health concern globally, in part because obesity complications such as hypertension, diabetes, and obstructive sleep apnea increase the risk of cardiovascular diseases. More than 10% weight loss may be required to prevent or reverse obesity complications. Treatment approaches to obesity include nutritional therapy, exercise therapy, pharmacotherapy, and surgical therapies. This review intends to identify the effects of weight loss on cardiovascular outcomes in patients with obesity and obstructive sleep apnea. Despite the strong association between cardiovascular diseases and obstructive sleep apnea, randomized trials have failed to demonstrate that treatment of obstructive sleep apnea reduces cardiovascular events, even in patients with established cardiovascular diseases. Weight loss in patients with obstructive sleep apnea improves HbA1c, systolic blood pressure, HDL cholesterol, and triglycerides, but thus far no changes in cardiovascular events have been shown. The combination of weight loss with continuous positive airway pressure (CPAP) appears more beneficial than either treatment in isolation. Large well-controlled trials in patients with obstructive sleep apnea to assess the effects of different weight reduction programs on cardiovascular disease are still needed.

Dose response relationship between positive airway pressure therapy and excessive daytime sleepiness: the HomePAP study

STUDY OBJECTIVES

Clinical benefits of PAP therapy for OSA are assumed to require adherent PAP usage, as defined by CMS as ≥ 4 hours of use ≥ 70% of nights. However, this is based on early data and does not necessarily capture improvements at subthreshold adherence. We explored dose-response relationships between PAP adherence measures and EDS from the HomePAP RCT.

METHODS

Participants ≥18 years with apnea hypopnea index ≥ 15 and baseline sleepiness (Epworth Sleepiness Scale (ESS) ≥ 12) received PAP therapy. Data were collected at baseline, 1-month, and 3-months follow-up. Regression models and receiver operating characteristic curves evaluated PAP measures as predictors of ESS change and normalization (ESS < 10).

RESULTS

In 119 participants (age 49.4 ± 12.6 years, 66.4% male, 72.3% white), > 50% were PAP non-adherent per CMS criteria at 3 months. Percent of nights with PAP use ≥ 4 hours predicted ESS change (p = 0.023), but not when controlling for AHI. Percent of nights with ≥ 4 hours and average PAP use provided the best discrimination for predicting ESS normalization; each 10% increase in PAP use ≥ 4 hours increased the odds of ESS normalization by 22% (p = 0.007); those using PAP ≥ 4 hours had nearly 3-fold greater odds of ESS normalization (p = 0.025). At least 4 hours and 70% of nights provided the best balance between specificity (0.50) and sensitivity (0.73).

CONCLUSIONS

Although sub-adherent PAP usage may still confer some benefit for OSA patients, adherence to current criteria confers the highest likelihood for ESS change and normalization.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Portable Monitoring for Diagnosis and Management of Sleep Apnea (HomePAP); Identifier: NCT00642486; URL: http://clinicaltrials.gov/show/NCT00642486.

Treatment preferences and willingness to pay in patients with obstructive sleep apnea: relevance of treatment experience

Background

Patients with obstructive sleep apnea (OSA) most commonly receive positive airway pressure therapy (PAP) as primary treatment, which is highly effective when used consistently. Little is known about the preferences for and relevance of attributes of OSA treatments, especially of non-PAP alternatives. The aim of this study was to evaluate treatment preferences and willingness to pay (WTP) among patients with and without previous experience of OSA therapies.

Methods

A discrete choice experiment and a structured survey were applied to patients presenting for overnight polysomnography at a tertiary sleep center. Medical variables were obtained from hospital case records.

Results

Over a period of 4 months, 241 subjects were enrolled and answered the questionnaire (61.8% with an existing diagnosis, 38.2% with a new diagnosis). The most preferred treatment among all patients was PAP therapy (51.1%), followed by mandibular advancement devices (18.1%), hypoglossal nerve stimulation (17.2%), and medication (13.7%). Approval for the different treatments varied by gender as well as by OSA therapy experience. The importance of attributes of OSA treatment varied too, with low rates of treatment-related side effects being equally important, independent of the preferred therapy. The most often stated monthly WTP for optimal sleep was € 50, with increasing age leading to lower WTP values.

Conclusion

Preferences for OSA therapies vary among patients and patient subgroups. PAP therapy is the most preferred treatment, though non-PAP interventions receive high approval ratings too, particularly in treatment-naïve patients. The importance of treatment attributes varies as well, depending on the choice of preferred treatment.

New Paths in Respiratory Sleep Medicine: Consumer Devices, e-Health, and Digital Health Measurements

Sleep health and tracking sleep with contemporary wearables have become more popular. Sleep disorders, in particular, sleep-disordered breathing, have a higher prevalence than estimated previously. Many patients with apnea and hypopnea events suffer whereas others do not report complaints or show cardiovascular consequences. Assessment with wearables may support efforts to distinguish which type of apnea is related to aging and which to cardiovascular comorbidities. Innovative methods offer smart solutions for problems that are insufficiently addressed. Telemedical concepts help bring patients to sleep medicine expertise at an early stage. To use these methods clinically, they must be certified as medical devices.

Mandibular advancement device use in obstructive sleep apnea: ORCADES study 5-year follow-up data

STUDY OBJECTIVES

Mandibular advancement devices (MADs) are an alternative to continuous positive airway pressure for the management of obstructive sleep apnea (OSA). The ORthèse d'avanCée mAndibulaire dans le traitement en DEuxième intention du SAHOS sévère (ORCADES) study is investigating the long-term effectiveness of MAD therapy in patients with OSA who refused or were intolerant of continuous positive airway pressure. Five-year follow-up data are presented.

METHODS

Data were available in 172 of 331 patients treated with a custom-made computer-aided design/computer-aided manufacturing biblock MAD (Narval CC; ResMed, Saint-Priest, France). The primary end point was treatment success (≥50% decrease in apnea-hypopnea index from baseline).

RESULTS

Five-year treatment success rates were 52% overall and 25%, 52%, and 63%, respectively, in patients with mild, moderate, or severe OSA. This reflects a decline over time vs 3-6 months (79% overall) and 2 years (68%). Rates declined in all patient subgroups but to the greatest extent in patients with mild OSA. The slight worsening of respiratory parameters over time was not associated with any relevant changes in sleepiness and symptoms. Moderate or severe OSA at baseline, treatment success at 3-6 months, and no previous continuous positive airway pressure use were significant independent predictors of 5-year treatment success on multivariate analysis. No new safety signals emerged during long-term follow-up. The proportion of patients using their MAD for ≥4 h/night on ≥4 days/wk was 93.3%; 91.3% of patients reported device use of ≥6 h/night at 5 years. At 5-year follow-up, 96.5% of patients reported that they wanted to continue MAD therapy.

CONCLUSIONS

Long-term MAD therapy remained effective after 5 years in >50% of patients, with good levels of patient satisfaction and adherence.

CITATION

Vecchierini MF, Attali V, Collet JM, et al. Mandibular advancement device use in obstructive sleep apnea: ORCADES study 5-year follow-up data. J Clin Sleep Med. 2021;17(8):1695-1705.

Weight Loss as the First-Line Therapy in Patients with Severe Obesity and Obstructive Sleep Apnea Syndrome: the Role of Laparoscopic Sleeve Gastrectomy

PURPOSE

The objective of this study is to investigate the effects of laparoscopic sleeve gastrectomy (LSG) on the polysomnographic parameters related to OSAS.

MATERIALS AND METHODS

We conducted this 3-year prospective cohort study in a tertiary care center between December 2016 and December 2019. In total, we enrolled 31 patients with severe obesity who underwent full-night polysomnography (PSG) before LSG. Later, the patients were re-evaluated by full-night PSG 12 months after the surgery.

RESULTS

The mean age of the patients was 44.1 ± 9.6 years. The mean body mass index (BMI) decreased significantly from a mean value of 49.8 ± 8.5 kg/m² at baseline to 33.2 ± 8.2 kg/m² and a percent BMI (%BMI) reduction of 33.8 ± 10.4% and a percent total weight loss (%TWL) of 35.4 ± 10.8% was achieved on the same day of the postsurgical PSG (p < 0.001). There was a remarkable improvement in the AHI (baseline: 36.1 ± 27.1, 12 months after the surgery: 10.3 ± 11.8; difference: 25.8 ± 22.8 events per hour) (p < 0.001). Importantly, there was a decrease in the percentage of non-rapid eye movement (NREM) 2 (p < 0.001), whereas NREM 3 and REM stages witnessed a significant increase (p = 0.001 and p < 0.001, respectively) after the surgery.

CONCLUSION

The results of this study showed that weight loss after LSG yields improvement not only in AHI but also in many polysomnographic parameters such as sleep quality and desaturation indices.

Telemedicine for Continuous Positive Airway Pressure in Sleep Apnea. A Randomized, Controlled Study

Rationale: Continuous positive airway pressure (CPAP) is the standard treatment for the obstructive sleep apnea syndrome (OSAS), but long-term adherence remains a challenge. In a pilot study, we observed that telemedicine combined with telemetrically triggered interventions was associated with improved CPAP adherence in the first month of treatment.Objectives: In the current randomized, controlled phase III trial, we aimed to collect pivotal data for the use of telemedicine in CPAP treatment of patients with OSAS.Methods: Symptomatic patients with OSAS were randomized to a telemedicine or control arm and initiated CPAP treatment. Phone calls were triggered in the telemedicine group during the first month of treatment upon either poor use or excessive mask leakage. Patients were followed for 6 months. Measures of CPAP use at 6 months were the main study endpoints.Results: Among 240 patients enrolled, 71 (30%) discontinued CPAP treatment over the course of the study. The primary outcome measure, the proportion of nights with CPAP use greater than 1 hour, was not statistically different in the telemedicine group (92.0%) versus the control group (88.2%) (P = 0.565). The daily hours of CPAP use at 6 months also did not differ significantly between the telemedicine group (5.6 h) and the control group (4.8 h) (P = 0.663). However, in a post hoc analysis, telemedicine led to increased device use in a subgroup of patients with a mild form of disease (5.6 h vs. 3.4 h; P = 0.026). The telemedicine-based intervention had a positive impact on sleep-related quality of life as measured with the Quebec Sleep Questionnaire (5.55 vs. 5.49 at 1 mo [P = 0.020]; 5.61 vs. 5.46 at 6 mo [P = 0.013]).Conclusions: A telemetrically triggered intervention in the first month of treatment did not improve CPAP use in the study population overall, but it had positive effects in patients with a mild form of OSAS and led to an improvement in sleep-related quality of life.Clinical trial registered with www.clinicaltrials.gov (NCT01715194).

Acceptance of and six-month adherence to continuous positive airway pressure in patients with moderate to severe obstructive sleep apnea

BACKGROUND

Continuous positive airway pressure (CPAP) is the most effective treatment for moderate to severe obstructive sleep apnea (OSA). Acceptance of and adherence to CPAP are crucial for optimal treatment outcomes. The aim of this study was to investigate the factors influencing patients' acceptance of and adherence to CPAP treatment.

METHODS

One hundred eighty-eight patients with moderate to severe OSA who had received CPAP titration from October 2017 to September 2018 were recruited. They were interviewed at 2 weeks and at 6 months to assess CPAP use and barriers to acceptance and adherence.

RESULTS

One hundred fourteen patients (60.6%) accepted CPAP treatment. Disease severity, assessed by apnea-hypopnea index (AHI) (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.08), subjective satisfaction of titration (OR, 12.83; 95% CI, 3.83-42.99), initial intention of CPAP therapy (OR, 3.33; 95% CI, 1.05-10.51) and short-term home CPAP trial (OR, 9.40; 95% CI, 2.85-31.08) were associated with acceptance of CPAP treatment. Two-third of the 98 CPAP acceptors reported good CPAP adherence at 6 months follow-up. Average hours of CPAP use per day for the first 2 weeks (OR, 1.88; 95% CI, 1.28-3.04) and the global problems associated with CPAP use (OR, 0.82; 95% CI, 0.73-0.91) were independent predictors of the six-month CPAP adherence.

CONCLUSIONS

Nearly 40% of patients with moderate to severe OSA did not accept CPAP treatment, and one-third of those CPAP acceptors had poor adherence to CPAP treatment. Improvement in disease awareness, comfortable titration experience, short-term home CPAP trial may be of help to increase CPAP acceptance and early experience with CPAP is important for long-term adherence. The differences in predicting factors for CPAP acceptance and adherence highlight the importance of focusing on specific aspects during the whole process management of OSA.

Cost-Benefit Analysis From the Payor's Perspective for Screening and Diagnosing Obstructive Sleep Apnea During Inpatient Rehabilitation for Moderate to Severe TBI

OBJECTIVE

To describe the cost benefit of 4 different approaches to screening for sleep apnea in a cohort of participants with moderate to severe traumatic brain injury (TBI) receiving inpatient rehabilitation from the payor's perspective.

DESIGN

A cost-benefit analysis of phased approaches to sleep apnea diagnosis.

SETTING

Six TBI Model System Inpatient Rehabilitation Centers.

PARTICIPANTS

Trial data from participants (N=214) were used in analyses (mean age 44±18y, 82% male, 75% white, with primarily motor vehicle-related injury [44%] and falls [33%] with a sample mean emergency department Glasgow Coma Scale of 8±5).

INTERVENTION

Not applicable.

MAIN OUTCOME

Cost benefit.

RESULTS

At apnea-hypopnea index (AHI) ≥15 (34%), phased modeling approaches using screening measures (Snoring, Tired, Observed, Blood Pressure, Body Mass Index, Age, Neck Circumference, and Gender [STOPBANG] [-$5291], Multivariable Apnea Prediction Index MAPI [-$5262]) resulted in greater cost savings and benefit relative to the portable diagnostic approach (-$5210) and initial use of laboratory-quality polysomnography (-$5,011). Analyses at AHI≥5 (70%) revealed the initial use of portable testing (-$6323) relative to the screening models (MAPI [-$6250], STOPBANG [-$6237) and initial assessment with polysomnography (-$5977) resulted in greater savings and cost-effectiveness.

CONCLUSIONS

The high rates of sleep apnea after TBI highlight the importance of accurate diagnosis and treatment of this comorbid disorder. However, financial and practical barriers exist to obtaining an earlier diagnosis during inpatient rehabilitation hospitalization. Diagnostic cost savings are demonstrated across all phased approaches and OSA severity levels with the most cost-beneficial approach varying by incidence of OSA.

Incidence and predictors of adherence to sleep apnea treatment in rehabilitation inpatients with acquired brain injury

OBJECTIVE

The purpose of this study was to describe incidence and assess predictors of adherence to Positive Airway Pressure (PAP) therapy for Obstructive Sleep Apnea (OSA) in persons with acquired brain injury (ABI).

METHODS

A 2012-2015 retrospective analysis of consecutive ABI patients admitted for neurorehabilitation, referred for polysomnography (PSG), and prescribed PAP for OSA. Univariable linear regressions were conducted to examine predictors of average hours of nightly PAP use. Univariable logistic regressions were conducted to examine predictors of PAP adherence using the conventional clinical definition of ≥4 h per night ≥70% of the time. Persons with traumatic etiology were separately analyzed.

RESULTS

ABI etiology was 51% traumatic, 36% stroke, and 13% other nontraumatic causes. Nearly two-thirds were nonadherent to PAP. For the overall sample, higher average nightly PAP usage was significantly predicted by positive hypertension diagnosis (β = 0.271, p = 0.019). Likewise, greater adherence based on the conventional cutoff was predicted by poorer motor functioning at hospital admission (OR = 0.98, p = 0.001) and lower oxygen saturation nadir (OR = 0.99, p = 0.003). For those with traumatic injuries, greater adherence was predicted by poorer functional status at hospital admission (OR = 0.98, p = 0.010) and positive hypertension diagnosis (OR = 0.16, p = 0.023).

CONCLUSIONS

In this study of hospitalized neurorehabilitation patients with ABI and comorbid OSA, predictors of adherence included lower oxygen saturation, poorer functional status and hypertension diagnosis, perhaps signifying the role of greater severity of illness on treatment adherence. High rates of refusal and nonadherence to frontline PAP therapy for sleep apnea is a concern for persons in recovery form ABI who are at a time of critical neural repair.

Predictors of long-term adherence to continuous positive airway pressure in patients with obstructive sleep apnea and cardiovascular disease

Study Objectives

Poor adherence to continuous positive airway pressure (CPAP) commonly affects therapeutic response in obstructive sleep apnea (OSA). We aimed to determine predictors of adherence to CPAP among participants of the Sleep Apnea and cardioVascular Endpoints (SAVE) trial.

Methods

SAVE was an international, randomized, open trial of CPAP plus usual care versus usual care (UC) alone in participants (45–75 years) with co-occurring moderate-to-severe OSA (≥12 episodes/h of ≥4% oxygen desaturation) and established cardiovascular (CV) disease. Baseline sociodemographic, health and lifestyle factors, OSA symptoms, and 1-month change in daytime sleepiness, as well as CPAP side effects and adherence (during sham screening, titration week, and in the first month), were entered in univariate linear regression analyses to identify predictors of CPAP adherence at 24 months. Variables with p <0.2 were assessed for inclusion in a multivariate linear mixed model with country, age, and sex included a priori and site as a random effect.

Results

Significant univariate predictors of adherence at 24 months in 1,121 participants included: early adherence measures, improvement in daytime sleepiness at 1 month, fixed CPAP pressure, some measures of OSA severity, cardiovascular disease history, breathing pauses, and very loud snoring. While observed adherence varied between countries, adherence during sham screening, initial titration, and the first month of treatment retained independent predictive value in the multivariate model along with fixed CPAP pressure and very loud snoring.

Conclusions

Early CPAP adherence had the greatest predictive value for identifying those at highest risk of non-adherence to long-term CPAP therapy.

Clinical Trial Registration

SAVE is registered with clinicaltrials.gov (NCT00738179).

Very low frequency component of heart rate variability as a marker for therapeutic efficacy in patients with obstructive sleep apnea: Preliminary study

BACKGROUND

Although positive airway pressure (PAP) therapy is effective for treating obstructive sleep apnea (OSA), some patients with severe OSA are intolerable to this treatment, which may lead to an increase in the mortality and morbidity of cardiovascular diseases. We investigated the relationship between heart rate variability (HRV) and sleep parameters during natural sleep and treatment of patients with OSA.

MATERIALS AND METHODS

This was the cross-sectional observation study. Patients were 17 males with severe OSA who were unable to accept continuous PAP. Standard polysomnography was performed for two consecutive nights, i.e., during natural sleep and following night with bilevel PAP (BiPAP) treatment. Time-dependent responses of the amplitudes of low frequency (LF), very low frequency (VLF), and high frequency components of HRV were assessed with the technique of complex demodulation.

RESULTS

Apnea-hypopnea index, oxygen desaturation time, and percentage of stage 1 sleep were significantly reduced, whereas the percentages of rapid eye movement and stages 3 + 4 sleep were increased, by BiPAP treatment. Therapy also reduced the amplitudes of VLF and LF components of HRV. Difference in amplitudes of VLF during natural sleep and treatment with BiPAP was significantly correlated with difference in percentages of stage 1 and stages 3 + 4 sleep.

CONCLUSION

Therapy-induced amelioration of OSA and sleep quality was accompanied by decrease in the amplitudes of VLF components of HRV. The VLF component may thus reflect physiological changes in both autonomic activity and sleep structure and serve as an objective marker for therapeutic efficacy in patients with severe OSA.

Cost-effectiveness of continuous positive airway pressure therapy for obstructive sleep apnea: health care system and societal perspectives

Study Objectives

To determine cost-effectiveness of continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) in Australia for 2017–2018 to facilitate public health decision-making.

Methods

Analysis was undertaken of direct per-person costs of CPAP therapy (according to 5-year care pathways), health system and other costs of OSA and its comorbidities averted by CPAP treatment (5-year adherence rate 56.7%) and incremental benefit of therapy (in terms of disability-adjusted life years [DALYs] averted) to determine cost-effectiveness of CPAP. This was expressed as the incremental cost-effectiveness ratio (= dollars per DALY averted). Direct costs of CPAP were estimated from government reimbursements for services and advertised equipment costs. Costs averted were calculated from both the health care system perspective (health system costs only) and societal perspective (health system plus other financial costs including informal care, productivity losses, nonmedical accident costs, deadweight taxation and welfare losses). These estimates of costs (expressed in US dollars) and DALYs averted were based on our recent analyses of costs of untreated OSA.

Results

From the health care system perspective, estimated cost of CPAP therapy to treat OSA was $12 495 per DALY averted while from a societal perspective the effect was dominant (−$10 688 per DALY averted) meaning it costs more not to treat the problem than to treat it.

Conclusions

These estimates suggest substantial community investment in measures to more systematically identify and treat OSA is justified. Apart from potential health and well-being benefits, it is financially prudent to do so.

Predictors of positive airway pressure therapy termination in the first year: analysis of big data from a German homecare provider

Background

There is a lack of robust data about factors predicting continuation (or termination) of positive airway pressure therapy (PAP) for sleep apnea. This analysis of big data from a German homecare provider describes patients treated with PAP, analyzes the therapy termination rate over the first year, and investigates predictive factors for therapy termination.

Methods

Data from a German homecare service provider were analyzed retrospectively. Patients who had started their first PAP therapy between September 2009 and April 2014 were eligible. Patient demographics, therapy start date, and the date of and reason for therapy termination were obtained. At 1 year, patients were classified as having compliance-related therapy termination or remaining on therapy. These groups were compared, and significant predictors of therapy termination determined.

Results

Of 98,329 patients included in the analysis, 11,702 (12%) terminated PAP therapy within the first year (after mean 171 ± 91 days). There was a U-shaped relationship between therapy termination and age; therapy termination was higher in the youngest (< 30 years, 15.5%) and oldest (≥ 80 years, 19.8%) patients, and lower in those aged 50–59 years (9.9%). Therapy termination was significantly more likely in females versus males (hazard ratio 1.48, 95% confidence interval 1.42–1.54), in those with public versus private insurance (1.75, 1.64–1.86) and in patients whose first device was automatically adjusting or fixed-level continuous positive airway pressure versus bilevel or adaptive servo-ventilation (1.28, 1.2–1.38).

Conclusions

This analysis of the largest dataset investigating PAP therapy termination identified a number of predictive factors. These can help health care providers chose the most appropriate PAP modality, identify specific patient phenotypes at higher risk of stopping PAP and target interventions to support ongoing therapy to these groups, as well as allow them to develop a risk stratification tool.

Untreated Sleep Apnea: An Analysis of Administrative Data to Identify Risk Factors for Early Nonadherence

STUDY OBJECTIVES

Discontinuation of positive airway pressure (PAP) treatment for obstructive sleep apnea (OSA) is widely reported, but research has not adequately addressed nonadherence with diagnostic testing for sleep disorders and initiation of PAP. This study sought to identify drivers of nonadherence with diagnostic sleep testing and PAP treatment initiation among patients preauthorized for these services.

METHODS

This observational cohort study used preauthorization records from a sleep management program and administrative medical claims from a large commercial health insurer. Participants included adults preauthorized for sleep testing and a subset in whom OSA was diagnosed and who were preauthorized for PAP treatment. Outcome measures were nonadherence with diagnostic sleep testing and PAP treatment initiation, identified as lack of a claim for a preauthorized service within 3 months of preauthorization of that service. Risk factors for nonadherence included patient demographics, prescribing factors, signs and symptoms of OSA, comorbidities, and prior health service utilization.

RESULTS

Of 51,749 patients preauthorized for diagnostic testing, 23.5% did not undergo testing. Among 19,968 patients preauthorized for PAP treatment, 11.1% did not initiate treatment. Testing and treatment ordered by primary care providers, residence outside the Midwest region, and two or fewer office visits within 6 months before preauthorization were strong predictors of nonadherence. Apnea-hypopnea index score < 30 events/h was also a strong predictor of nonadherence with treatment initiation.

CONCLUSIONS

This study adds to existing knowledge about risk factors for nonadherence with sleep testing and treatment initiation following preauthorization. Health plans and providers should develop strategies to better engage patients with higher risk of nonadherence.

Obstructive Sleep Apnea and the Impact on Surgical Outcomes in Gynecology

Importance

Obstructive sleep apnea syndrome (OSAS) is a common medical condition in the United States and affects gynecologic surgical outcomes.

Objective

The aim of this review was to improve perioperative diagnosis and management of OSAS in patients presenting for gynecologic surgery and ultimately improve perioperative outcomes. The role of preoperative evaluation and screening is also addressed.

Evidence Acquisition

Medical databases were queried for publications pertaining to OSAS complications, risk factors, screening, and perioperative management. Pertinent articles were reviewed by the study authors.

Results

Obstructive sleep apnea syndrome is underdiagnosed in the preoperative surgical population. Obesity and other risk factors for OSAS are prevalent in patients with gynecologic issues but are not fully assessed with screening prior to surgery. Effective treatment modalities, such as continuous positive airway pressure, and perioperative management strategies are available to improve patient outcomes.

Conclusions and Relevance

Increased diagnosis and treatment for OSAS in the perioperative period can improve perioperative outcomes, surgical outcomes, and long-term patient outcomes. Strategies to increase effective management in patients presenting for gynecologic surgery are needed.

CPAP Adherence Predictors in a Randomized Trial of Moderate-to-Severe OSA Enriched With Women and Minorities

BACKGROUND

Suboptimal CPAP adherence in OSA clinical trials involving predominantly white men limits interpretability and generalizability. We examined predictors of CPAP adherence in a clinical trial enriched with minorities.

METHODS

The Sleep Apnea Stress Study-a randomized, double-blind, sham-controlled trial of patients with moderate-to-severe OSA-included participants with complete 8-week adherence data (n = 138). Overnight 14-channel polysomnography, anthropometry, socioeconomic status, mood questionnaires, and week 1 CPAP adherence were analyzed via adjusted linear models relative to CPAP adherence (average minutes per night usage).

RESULTS

Overall, age was 51 ± 12 years, 55% of the patients were male, 55% were white, BMI was 36.7 ± 7.7 kg/m², and median apnea-hypopnea index was 20 (interquartile range, 13-37). In univariate analyses adherence increased with randomization to active CPAP (81 min; 95% CI, 30-132), increasing age (35 min/decade; 95% CI, 13-57), white race (78 min, 95% CI, 26-129), and per hour of week 1 adherence (41 min, 95% CI, 32-51). Active CPAP (48 min, 95% CI, 6-91), increasing age (27 min/decade, 95% CI, 10-44), and higher 1-week adherence (36 min/h, 95% CI, 27-46) were significantly associated with improved adherence in multivariable analyses. Subgroup analyses showed stronger associations of adherence with treatment arm in whites and increasing age in minorities. Increasing age and white race were more strongly associated with adherence in women.

CONCLUSIONS

In this trial with near-even sex distribution and high ethnic minority representation, we identified CPAP assignment, increasing age, and early adherence to be associated with improved adherence in addition to sex-specific and race-specific adherence differences. These results can inform targeted clinical trial adherence optimization strategies.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00607893; URL: www.clinicaltrials.gov.

Adaptive servo ventilation for central sleep apnoea in heart failure: SERVE-HF on-treatment analysis

This on-treatment analysis was conducted to facilitate understanding of mechanisms underlying the increased risk of all-cause and cardiovascular mortality in heart failure patients with reduced ejection fraction and predominant central sleep apnoea randomised to adaptive servo ventilation versus the control group in the SERVE-HF trial.Time-dependent on-treatment analyses were conducted (unadjusted and adjusted for predictive covariates). A comprehensive, time-dependent model was developed to correct for asymmetric selection effects (to minimise bias).The comprehensive model showed increased cardiovascular death hazard ratios during adaptive servo ventilation usage periods, slightly lower than those in the SERVE-HF intention-to-treat analysis. Self-selection bias was evident. Patients randomised to adaptive servo ventilation who crossed over to the control group were at higher risk of cardiovascular death than controls, while control patients with crossover to adaptive servo ventilation showed a trend towards lower risk of cardiovascular death than patients randomised to adaptive servo ventilation. Cardiovascular risk did not increase as nightly adaptive servo ventilation usage increased.On-treatment analysis showed similar results to the SERVE-HF intention-to-treat analysis, with an increased risk of cardiovascular death in heart failure with reduced ejection fraction patients with predominant central sleep apnoea treated with adaptive servo ventilation. Bias is inevitable and needs to be taken into account in any kind of on-treatment analysis in positive airway pressure studies.

Insomnia complaints in lean patients with obstructive sleep apnea negatively affect positive airway pressure treatment adherence

The objective of this study was to evaluate the determinants of long-term adherence to positive airway pressure treatment among patients with obstructive sleep apnea, with special emphasis on patients who stop positive airway pressure treatment within 1 year. This is a prospective long-term follow-up of subjects in the Icelandic Sleep Apnea Cohort who were diagnosed with obstructive sleep apnea between 2005 and 2009, and started on positive airway pressure treatment. In October 2014, positive airway pressure adherence was obtained by systematically evaluating available clinical files (n = 796; 644 males, 152 females) with moderate to severe obstructive sleep apnea (apnea-hypopnea index ≥15 events per h). The mean follow-up time was 6.7 ± 1.2 years. In total, 123 subjects (15.5%) returned their positive airway pressure device within the first year, 170 (21.4%) returned it later and 503 (63.2%) were still using positive airway pressure. The quitters within the first year had lower body mass index, milder obstructive sleep apnea, less sleepiness, and more often had symptoms of initial and late insomnia compared with long-term positive airway pressure users at baseline. Both initial and late insomnia were after adjustment still significantly associated with being an early quitter among subjects with body mass index <30 kg m^-2 , but not among those with body mass index ≥30 kg m^-2 . The prevalence of early quitters decreased significantly during the study period (2005-2009). Almost two-thirds of patients with moderate to severe obstructive sleep apnea are positive airway pressure users after 7 years. Obesity level, obstructive sleep apnea severity and daytime sleepiness are important determinants of long-term adherence. Symptoms of initial and late insomnia are associated with early quitting on positive airway pressure among non-obese subjects.

Work of Breathing in Fixed and Pressure Relief Continuous Positive Airway Pressure (C-Flex™): A post hoc Analysis

BACKGROUND

Expiratory pressure relief continuous positive airway pressure (pressure relief CPAP; C-Flex™) causes increases in inspiratory duty cycle and shortening of expiratory time. It has been suggested that these changes are caused by an increase in work of breathing.

OBJECTIVES

We studied the effects of C-Flex on work of breathing and intrinsic positive end-expiratory pressure as compared to fixed CPAP.

METHODS

Work of breathing was analyzed in 24 patients with obstructive sleep apnea during treatment with fixed CPAP and C-Flex with 3 different pressure relief settings in a randomized order during rapid-eye-movement (REM) and non-REM sleep. Work of breathing was assessed on a breath-by-breath basis using a piezoelectric esophageal pressure catheter and a pneumotachograph for measuring airflow.

RESULTS

We found there was no increase in inspiratory work of breathing observed using C-Flex compared to fixed CPAP. Instead, we found a linear decrease in inspiratory work of breathing with increasing pressure relief, with a mean difference of 1.22 J/min between CPAP and maximum pressure release (C-Flex 3; 90% of the value with nasal CPAP); however, the decrease was not statistically significant. The decrease in inspiratory work of breathing associated with C-Flex has a significant inverse correlation with BMI.

CONCLUSIONS

The C-Flex technology does not change work of breathing but shows a tendency towards a reduction of inspiratory work of breathing in patients with a lower BMI using higher C-Flex. The effect is probably caused by diminishing airway resistance generated by the positive end-expiratory pressure. Our findings may lead to additional fields of application of the C-Flex technology, such as chronic obstructive pulmonary disease or muscular dystrophy.

Impact of a New Nasal Pillows Mask on Patients' Acceptance, Compliance, and Willingness to Remain on CPAP Therapy

Aim. Continuous positive airway pressure (CPAP) masks are a key factor in patient compliance. This program assessed the performance of a new nasal pillows mask (NPM) on a variety of new and established obstructive sleep apnea (OSA) patients using CPAP therapy. Methods. Five programs were developed to assess the new NPM [AirFit P10, ResMed] on naïve patients; patients established on another NPM; patients using a nasal mask; patients with low CPAP compliance; and patients who wished to stop using CPAP therapy. Results. A total of 212 patients were included. In naïve patients, CPAP usage after 3 months was 5.9 ± 1.7 hours/night, compared with the control group at 4.6 ± 2.4 hours/night (p < 0.05). In patients established on another NPM, usage improved to 7.4 ± 1.1 hours/night versus 6.7 ± 1.4 (p = 0.001). 78% of nasal mask users wished to continue using the new NPM. Low compliance patients improved with an average of 0.87 hours/night (p = 0.001) when using the new NPM. In patients at the point of quitting CPAP, 60% continued with therapy using the new NPM. Conclusion. The new NPM mask performed well in a variety of clinical groups of OSA patients receiving CPAP therapy and shows that technical advances in CPAP masks can improve patient compliance.

A clinical approach to obstructive sleep apnea as a risk factor for cardiovascular disease

Obstructive sleep apnea (OSA) is associated with cardiovascular risk factors, cardiovascular diseases, and increased mortality. Epidemiological studies have established these associations, and there are now numerous experimental and clinical studies which have provided information on the possible underlying mechanisms. Mechanistic proof-of-concept studies with surrogate endpoints have been performed to demonstrate that treatment of OSA by continuous positive airway pressure (CPAP) has the potential to reverse or at least to attenuate not only OSA but also the adverse cardiovascular effects associated with OSA. However, no randomized studies have been performed to demonstrate that treatment of OSA by CPAP improves clinical outcomes in patients with cardiovascular risk factors and/or established cardiovascular disease and concomitant OSA. In the present review, we summarize the current knowledge on the role of OSA as a potential cardiovascular risk factor, the impact of OSA on cardiac function, the role of OSA as a modifier of the course of cardiovascular diseases such as coronary artery disease, atrial fibrillation, and heart failure, and the insights from studies evaluating the impact of CPAP therapy on the cardiovascular features associated with OSA.