Morgenthaler, Timothy I.

Purpose of review Mask choice is among the few modifiable determinants of positive airway pressure (PAP) effectiveness in adults with obstructive sleep apnea OSA), yet selection is often shaped by convention, habit, or local inventory rather than evidence. We review recent literature, emphasizing studies from the past 18 months and incorporating foundational mechanistic and outcomes studies that should influence prescribing choices. Recent findings Population-scale telemonitoring analyses confirm that nasal interfaces outperform oronasal masks on adherence, required pressure, residual apnea–hypopnea index (AHI), and unintentional leak. Switching patients from an oronasal to a nasal mask can increase adherence by up to 77%. Drug-induced sleep endoscopy with PAP, cine MRI, and sealed-compartment physiology suggest three main mechanisms for these observations: oral pressure transmission without oral airflow, posterior tongue and mandibular displacement, and increased pharyngeal collapsibility. Mandibular jaw-movement signals allow leak phenotyping that distinguishes mask-seal failure from mouth opening, supporting targeted intervention rather than reflexive interface change. Summary Current evidence supports a nasal-first prescribing strategy with structured early follow-up using telemonitored adherence, residual AHI, and leak waveform data. Oronasal masks should be reserved for documented and structured nasal-trial failure rather than selected on the basis of self-reported breathing route.

ABSTRACT Obstructive sleep apnea (OSA) is a common, heritable disorder with diverse clinical presentations and etiologies. We conducted a genome-wide association meta-analysis of 492,107 individuals, including 46,028 OSA cases, identifying 14 genome-wide significant loci, eight of which are novel. Analyses adjusting for body mass index (BMI) revealed three loci independent of obesity, implicating alternative biological pathways contributing to disease. Integrative functional analyses, including chromatin interaction mapping, fine-mapping, and eQTL colocalization, prioritized candidate effector genes. Notably, implicated genes in chondrocytes were associated with craniofacial morphology in both mouse and human multivariate genotype-phenotype mapping, supporting a role for craniofacial structure in OSA risk. These findings highlight key genetic pathways (obesity-related, neurological, and craniofacial) underlying the development of OSA, offering new insights into its complex etiology.

Background: The COVID-19 pandemic brought profound changes to health care systems worldwide. This study examines the adaptive responses of a sleep medicine practice that successfully pivoted to telemedicine, remote diagnostics, and agile operations, resulting in sustained growth and improved patient accessibility. Methods: We analyzed organizational and cultural elements enabling responsiveness, including telemedicine infrastructure, adaptive leadership, quality-focused processes, and effective communication. Objective outcomes were assessed by analyzing patient demographics, telemedicine visits, and sleep testing patterns during three phases: pre-pandemic (June 1, 2018 to March 8, 2020), acute COVID-19 (March 9, 2020 to April 19, 2020), and post-acute COVID-19 (April 20, 2020 to December 31, 2021). Results: Across 105,199 encounters, monthly sleep medicine visits and testing declined ∼50% during acute COVID-19, but rebounded to surpass baseline in the post-acute phase. Virtual visits increased significantly, replacing many face-to-face encounters. Home sleep apnea test use rose sharply, driven by disposable WatchPAT tests, while polysomnography use decreased. Testing volumes increased overall post-acute compared with pre-pandemic. Patients served during acute and post-acute phases were younger, more often female, non-White, and postgraduate-educated (all p < 0.001). Nonlocal patients increased during the post-acute phase, reflecting telemedicine expansion. Conclusions: Proactive telemedicine investments, adaptive leadership, quality-focused processes, and effective communication enabled this practice to adapt successfully during the pandemic. These resilience strategies provide a model for navigating future health care challenges, underscoring telemedicine and e-health’s critical roles in maintaining care delivery during crises.

Abstract Introduction The SleepImage is an HSAT device (sHSAT) that uses photoplethysmography and oxygen saturation data to generate an apnea hypopnea index (AHI). This sHSAT has been FDA cleared as a software-as-a-medical-device for use in children 2 years and older for diagnosing obstructive sleep apnea (OSA). To our knowledge this sHSAT has not been tested on children concurrent with the gold standard polysomnography (PSG). Methods This study evaluated 50 children 2-6 years of age with tonsillar hypertrophy and OSA symptoms with sHSAT during simultaneous in-lab PSG. Aims were to determine the technical feasibility of using sHSAT in this population and to compare sHSAT results to PSG. The primary endpoint was AHI by sHSAT compared to AHI by PSG and presence of OSA. Sensitivity analysis was performed for presence or absence of OSA diagnosis based on sHSAT versus PSG. Bland-Altman and concordance correlation calculations were used for comparisons. Results 50 patients, median age 4 (IQR 3-5), met criteria; 39 completed PSG and HSAT. The sensitivity with sHSAT for OSA prevalence based on proprietary categorization was 94.1%, specificity 22.7%, LR+ 1.22, and LR- 0.26, with PSG OSA prevalence of 43.6%. There was a 9% sHSAT total failure rate, and the device frequently fell off, resulting in TST difference of -226.9 ±182.8 min between sHSAT and PSG. PSG was trimmed to include only segments where HSAT was confirmed to be on before comparisons. Concordance correlation coefficient between sAHI and AHI-PSG was 0.52. The Bland-Altman analysis comparing sAHI and PSG AHI revealed a mean difference of 0.73 (95% confidence limits: -3.47 to 4.93). Considering only obstructive events, the Bland-Altman the sAHI vs the AHI-PSG shows a mean difference of 1.52 (95%CI -5.40 to 8.44). Conclusion This pilot study demonstrated challenges with feasibility in using the sHSAT in this age group given likelihood of technical difficulties leading to absent or truncated data. When compared with PSG, sHSAT demonstrated a high false-positive rate for diagnosis of OSA, particularly concerning if guiding surgical management. This topic is of considerable importance to the practice of pediatric sleep medicine; further investigation of technological advances in this area is imperative. Support (if any)

Abstract Introduction Despite AASM scoring guidelines encouraging classifying hypopneas as central or obstructive, classification is underutilized in practice. However, without that effort patients may receive an incorrect primary diagnosis and suboptimal treatment. The remedē® System Pivotal Trial studied transvenous phrenic nerve stimulation (TPNS) to treat adult patients with moderate to severe central sleep apnea (CSA). Entry criteria required apnea hypopnea index (AHI)≥20 with the central apnea index (CAI) greater than the obstructive apnea index and obstructive apneas&lt; 20% of AHI but did not consider hypopnea differentiation. This analysis re-examined sleep studies from the trial to assess how hypopnea classification might lead to better patient selection for this therapy. Methods Hypopneas were classified as central versus obstructive by a sleep core laboratory following a modified version of AASM recommended criteria. The AHI composition was assessed at baseline and after 6 months of therapy. Results At baseline, 91% (138/151) of patients had ≥50% of events classified as central when accounting for hypopnea classification. If all hypopneas were assumed to be obstructive, only 63% (95/151) would have had ≥50% central events. Additionally, 95% (144/151) of patients had central AHI ≥15/hour, compared to 73% (110/151) with a central apnea index (CAI) ≥15/hour. The likelihood of achieving a ≥50% AHI reduction increased with the percentage of baseline events that were central: responder rates were 37.5% for patients with &lt; 50% central events at baseline, incrementally increasing to 76.5% for those with ≥90% central events. At 6 months, the residual AHI predominantly consisted of obstructive events. Central events decreased by 89% with treatment, from a baseline median of 32/hour [1st and 3rd quartiles: 22, 50]. Obstructive apneas rose by 2/hour and obstructive hypopneas increased by 2/hour from a baseline median of 5 obstructive events/hour [2, 12]. Conclusion Distinguishing central from obstructive hypopneas is required to accurately determine if a patient has central sleep apnea/Cheyne Stokes respiration, and is crucial for epidemiologic studies, appropriate therapy selection, and managing patient expectations about treatment outcomes. This analysis suggests that accurate hypopnea classification may prevent disqualification of patients who could benefit from TPNS therapy, which effectively treats central sleep apnea syndrome. Support (if any) ZOLL Respicardia, Inc.

Abstract Introduction Obstructive sleep apnea (OSA) is effectively treated with continuous positive airway pressure (CPAP), but access remains a challenge. The COVID-19 pandemic accelerated telehealth, offering a convenient alternative to in-person visits for OSA evaluation and treatment initiation. This study compares patients managed entirely via video telehealth to those managed entirely in person. We hypothesize that virtual are as effective as in-person evaluations in managing most OSA patients. Methods The study is approved by the Mayo Clinic IRB. We retrospectively studied adult patients diagnosed with OSA requiring CPAP initiation between June 2020–2023. Data collected included baseline demographics, home sleep apnea testing (HSAT) results, polysomnography (PSG) results, Epworth Sleepiness Scale (ESS) scores, OSA severity, compliance results, other relevant comorbidities (i.e. cardiovascular diseases). Visit type categorized as “in-person” for patients who had both initial and follow-up appointments in-person, while “telehealth” group included patients who had both appointments virtually. Results Of 59 patients, 33 had telehealth (56%). The groups had similar medians in age (66 vs 62), sex (73% vs 67% male), and BMI (30 vs 32). There was no significant difference in median ESS scores (8 vs 7, p=0.7). However, the severity of OSA (moderate to severe) was higher in the in-person group (73% vs 45%, p=0.03). When baseline sleep study data was investigated, there were no differences in AHI and average SpO2 values measured by HSAT or PSG between the two groups (p&gt;0.05 for all). CPAP compliance was significantly higher in the telehealth group compared to in-person (78% vs 40%, OR: 5.5, 95% CI: 1.7-17.1, p=0.003). Virtual visit type was the only independent predictor of compliance (p=0.006), after adjusting for age, BMI, comorbidities and OSA severity in multivariate analysis. However, there was no difference in average daily CPAP usage (6:39 vs 7:18, p=0.5) and percentage of days with usage &gt;4 hours (91% vs 95, p=0.5). Median AHI after treatment improved in both groups, with no significant difference between groups (1.7 vs 2.4, p=0.8). Conclusion Telehealth offers a successful alternative to in-person visits for OSA evaluation, with similar outcomes and significantly better compliance, enhancing OSA management. Support (if any)

Abstract Introduction Adherence with mask-based therapies remains a significant challenge for optimal treatment of patients with sleep disordered breathing. Transvenous phrenic nerve stimulation (TPNS) to treat central sleep apnea offers a novel, automated approach to enhance nightly adherence by initiating therapy based on patient-specific programmed conditions such as sleep schedule, activity, and body position. Therapy automatically pauses when the patient sits up or changes position, facilitating re-initiation of sleep. This research aimed to determine the degree of adherence achieved with TPNS’s automated activation approach. Methods Device data from 128 remedē® System Pivotal Trial participants were analyzed to calculate hours of therapy activation. Daily use from device data within the 14 days prior to scheduled visits were used to calculate median daily hours of therapy per patient, and subsequently the overall median daily use for all patients. Therapy duration was defined as the sum of time of delivered therapy when all conditions to activate therapy were met between the first time therapy came on to the last time off during the night, excluding time when activity or body position did not meet the programmed criteria for therapy activation. Results The median [Q1-Q3] nightly therapy duration at 6, 12, 18, and 24 months was 5.9 [4.9-6.6], 5.7 [5.0-6.8], 6.0 [5.3-6.8], and 5.9 [4.9-6.5] hours, respectively. Using a definition for adequate therapy as the percentage of patients with usage ≥4 hours/night for at least 70% of nights, 86%, 82%, 83%, and 90% of patients met the criteria at these visits. Only two patients (&lt; 2%) who had therapy activated discontinued treatment prior to 6 months due to stimulation intolerance. Patients with median delivered therapy ≥4 hours/night reported more quality of life improvement than patients with &lt; 4 hours of therapy. Conclusion The automatic activation of TPNS therapy resulted in a higher duration of nightly usage and higher rate of adequate delivered therapy than generally are reported for mask-based therapies. This high usage may yield a greater overall reduction in central sleep apnea burden over the whole night compared to therapies that require the patient to initiate the therapy. Support (if any) ZOLL Respicardia, Inc.

Abstract Introduction Residual excessive daytime sleepiness (RES) despite effective positive airway pressure (PAP) therapy for obstructive sleep apnea (OSA) is a clinical problem impacting quality of life and daily function. Wake-promoting agents (WPAs) such as modafinil, armodafinil, and solriamfetol have demonstrated efficacy in reducing RES in randomized controlled trials (RCTs); however, their effectiveness in typical sleep clinic populations remains underexplored. This study aimed to evaluate the efficacy, safety, and tolerability of these WPAs in real-world clinical settings. Methods This retrospective study analyzed electronic health records of 69 randomly selected, consenting patients with OSA who are on PAP therapy and a WPA at Mayo Clinic from 9/19/2019 to 9/19/2024. Researchers reviewed charts for treatment indication, duration, adverse effects, and response (categorized as “complete,” “partial,” or “poor”). Therapy longevity was assessed using initiation, refill, and discontinuation data. Outcomes were analyzed with paired t-tests, chi-square tests, and regression models. Results Of 69 patients, 45 were excluded because: WPA use before observation period (24), off-label WPA use (13), WPA use before CPAP (3), or other (5). Off-label reasons included neurologic-condition-related fatigue (6), depression augmentation (5), and autoimmune-condition-related fatigue (2). 24 patients were on WPAs for RES with PAP-treated OSA, including 3 with mixed indications, and were included in analyses. The median age was 65 (IQR 11). BMI at OSA diagnosis was 33.6 (IQR 6.4). Most subjects were male (75%). Initial Epworth Sleepiness Scale scores (ESS) were 12.3±1.1. ESS at the first WPA prescription were 15.4±0.9 (p=0.04). Most patients (83.3%) started on modafinil. Of the 4 patients who started on armodafinil or solriamfetol, chart review showed a previous trial of modafinil without benefit. After optimizing the initial WPA dosage, ESS improved by 3.3±1.4 points (p=0.04) to 12.1 ±1.2. Side effects limited WPA use in 20.8% of patients. Median first WPA duration was 141 days (IQR 53-280) with no significant difference between these WPAs (p=0.81). Conclusion Although WPAs have narrowly defined approved indications, they are often prescribed off-label for comorbidities. Unlike straightforward use in RCTs, real-life use is more complicated. Patients prescribed WPAs for the targeted approved indication show statistically significant benefits, although adverse effects limited their use for some. Support (if any)