Reduction In AHI Research Articles

Acetazolamide as an Add-on Therapy Following Barbed Reposition Pharyngoplasty in Obstructive Sleep Apnea: A Randomized Controlled Trial.

Surgical interventions, like barbed reposition pharyngoplasty (BRP), are a valuable alternative for patients with obstructive sleep apnea (OSA) who are unable to tolerate continuous positive airway pressure (CPAP). However, predicting surgical success remains challenging, partly due to the contribution of non-anatomical factors. Therefore, combined medical treatment with acetazolamide, known to stabilize respiratory drive, may lead to superior surgical results. This double-blind, parallel-group randomized controlled trial evaluates the efficacy of acetazolamide as an add-on therapy to BRP in OSA. A total of 26 patients with moderate to severe OSA undergoing BRP were randomized to receive either acetazolamide or placebo post-surgery for 16 weeks. The group who was treated with BRP in combination with acetazolamide showed a reduction in AHI of 69.4%, significantly surpassing the 32.7% reduction of the BRP + placebo group (p < 0.01). The sleep apnea-specific hypoxic burden also decreased significantly in the group who was treated with BRP + acetazolamide (p < 0.01), but not in the group receiving BRP + placebo (p = 0.28). Based on these results, acetazolamide as an add-on therapy following BRP surgery shows promise in improving outcomes for OSA patients, addressing both anatomical and non-anatomical factors.

Barbed Expansion Sphincter Pharyngoplasty (BESP) for the Treatment of OSA. “A Step Ahead”

Abstract Background expansion sphincter pharyngoplasty is one of the newly introduced techniques for treating OSA in the last 20 years that showed promising results by increasing the lateral dimensions of the oropharynx by pulling the lateral pharyngeal wall and anchoring it to the pterygomandibular raphe, the paper study the efficacy of performing the procedure using the barbed suture on moderate to severe OSA. Methods Twelve patients with moderate to severe OSA due to oropharyngeal collapse according to VOTE classification after DISE were assigned to the study. Pre- and post-operative Epworth sleepiness scale questionnaire was completed, Pre- and post-operative polysomnography was performed as an objective measurement, all patients underwent BESP and the duration, post- operative complications, and pain records were plotted. Results The technique was confirmed to be feasible with a success rate of 91.7%, with reduction of median AHI from (38.75 to 8.7 event/hour) and reduction of the mean ESS from (20.83 to 5.67) and mean ODI (37.62 to 9.38). Conclusion The barbed expansion sphincter pharyngoplasty is an effective technique for treating obstructive sleep apnea in patients with retropalatal and oropharyngeal collapse.

Weight reduction and the impact on apnea-hypopnea index: A systematic meta-analysis

Obstructive sleep apnea (OSA) is strongly associated with obesity. While the relationship between weight reduction and apnea-hypopnea index improvement has been documented, to our knowledge, it has not been quantified adequately. Therefore, this study aimed to quantify the relationship between weight reduction and AHI change. MethodsA systematic literature search was performed using meta-analyses (PRISMA) guidelines for studies reporting AHI and weight loss in people with obesity/overweight and OSA between 2000 and 2023. A linear and quadratic model (weighted by treatment arm sample size) predicted percent change from baseline AHI against mean percent change from baseline weight. The quadratic term was statistically significant (P < 0.05), so the quadratic model (with 95 % prediction interval) was used. ResultsThe literature search identified 27 studies/32 treatment arms: 15 using bariatric surgery and lifestyle intervention each and 2 using pharmacological interventions. Included studies were ≥3 months with weight intervention and participants had AHI ≥15/h. Weight reduction in people with OSA and obesity was associated with improvements in the severity of OSA. BMI reduction of 20 % was associated with AHI reduction of 57 %, while further weight reduction beyond 20 % in BMI was associated with a smaller effect on AHI. As the prediction intervals are relatively wide, a precise relationship could not be conclusively established. ConclusionThe degree of AHI index improvement was associated with the magnitude of weight reduction. The model suggests that with progress in weight reduction beyond 20 %, the incremental decrease in BMI appeared to translate to a smaller additional effect on AHI.

Comparison of classical method and microdebrider technique for adenoidectomy in pediatric patients with obstructive sleep apnea.

The aim of this study was to evaluate the safety and efficacy of microdebrider adenoidectomy on sleep-disordered breathing among pediatric patients with OSA. In the microdebrider group (Group I), there were 30 Japanese OSA patients consisting of 26 boys and 4 girls. For comparison, we had 15 children (13 boys and 2 girls) who underwent classical adenoidectomy (Group II). Patients in Group I were selected from a pool of 95 pediatric Japanese OSA patients and were matched by age, preoperative AHI, and Kaup index with those in Group II.Parameters such as the amount of residual adenoid tissue, bleeding, duration of the procedure, and sleep-related metrics were compared between the two groups. A significant improvement in postoperative AHI was observed in Group I (p<0.05). The prevalence of AHI <1 was significantly higher in Group I compared with Group II (p<0.05). Additionally, the amount of postoperative residual adenoid was significantly less in Group I (3/30 of Grade 3 and 4 adenoid size) than in Group II (7/15, p<0.05). Furthermore, a reduction in postoperative AHI was proportionally associated with a decrease in residual adenoid. The newly developed microdebrider adenoidectomy technique for pediatric OSA patients with adenotonsillar hypertrophy demonstrated greater accuracy and efficacy in ameliorating sleep apnea symptoms compared with the standard adenoidectomy approach.

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

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

0562 Evaluation of Habitual Sleep Duration and PAP Adherence to Quantify Effective AHI Reduction at Home in Older Adults

0562 Evaluation of Habitual Sleep Duration and PAP Adherence to Quantify Effective AHI Reduction at Home in Older Adults

Multi-center safety and efficacy study of a negative-pressure intraoral device in obstructive sleep apnea

BackgroundIntraoral devices, with or without negative oral pressure, can stabilize the oropharynx and reduce obstructive sleep apneas. We tested the hypothesis that treatment with the iNAP® Sleep Therapy System, which applies negative oral pressure through an intra-oral appliance, would reduce the severity of obstructive sleep apnea in a multi-center, prospective, first-night-randomized-order cross-over study. Methods/patients130 patients fulfilled the entry criteria (age <75, AHI 15–55, BMI <33), and 63 entered the primary endpoint cohort (Total Sleep Time ≥4 h/night on the baseline polysomnogram and an oral negative vacuum time maintained by iNAP® ≥ 4 h/night and total sleep time ≥4 h/night during the first treatment study). 54 patients completed a second treatment sleep study at least 28 days after the first sleep study. ResultsAmong the primary endpoint cohort (n = 63, age = 53.2 ± 11.3, BMI = 27.1 ± 2.8), 33 patients (52 %; 95 % confidence interval = 40%–64 %, p < 0.001) responded to iNAP treatment according to the Sher criteria (>50 % reduction in AHI and an AHI ≤20 events/hr). The average oxy-hemoglobin saturation increased by 1–2%, and the average percent oxygen desaturation decreased (was less severe) by 1 % while using the iNAP device. The incidence of adverse events, all self-limited, was low. The reduction in the apnea-hypopnea index was durable over the 28-day study. Patients used iNAP on average 5.6 h per night during the study period. ConclusionThe iNAP® Sleep Therapy System achieved a durable benefit in more than half the patients with moderate to severe obstructive sleep apnea and may be considered in patients who object to or failed continuous positive airway pressure. Clinical trial registrationClinicalTrials.gov Identifier: NCT02698059.

Preliminary Assessment of an Ambulatory Device Dedicated to Upper Airway Muscle Training in Patients With Sleep Apnea: Proof-of-Concept Study

Background Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a prevalent condition affecting a substantial portion of the global population, with its prevalence increasing over the past 2 decades. OSAHS is characterized by recurrent upper airway (UA) closure during sleep, leading to significant impacts on quality of life and heightened cardiovascular and metabolic morbidity. Despite continuous positive airway pressure (CPAP) being the gold standard treatment, patient adherence remains suboptimal due to various factors, such as discomfort, side effects, and treatment unacceptability. Objective Considering the challenges associated with CPAP adherence, an alternative approach targeting the UA muscles through myofunctional therapy was explored. This noninvasive intervention involves exercises of the lips, tongue, or both to improve oropharyngeal functions and mitigate the severity of OSAHS. With the goal of developing a portable device for home-based myofunctional therapy with continuous monitoring of exercise performance and adherence, the primary outcome of this study was the degree of completion and adherence to a 4-week training session. Methods This proof-of-concept study focused on a portable device that was designed to facilitate tongue and lip myofunctional therapy and enable precise monitoring of exercise performance and adherence. A clinical study was conducted to assess the effectiveness of this program in improving sleep-disordered breathing. Participants were instructed to perform tongue protrusion, lip pressure, and controlled breathing as part of various tasks 6 times a week for 4 weeks, with each session lasting approximately 35 minutes. Results Ten participants were enrolled in the study (n=8 male; mean age 48, SD 22 years; mean BMI 29.3, SD 3.5 kg/m2; mean apnea-hypopnea index [AHI] 20.7, SD 17.8/hour). Among the 8 participants who completed the 4-week program, the overall compliance rate was 91% (175/192 sessions). For the tongue exercise, the success rate increased from 66% (211/320 exercises; SD 18%) on the first day to 85% (272/320 exercises; SD 17%) on the last day (P=.05). AHI did not change significantly after completion of training but a noteworthy correlation between successful lip exercise improvement and AHI reduction in the supine position was observed (Rs=–0.76; P=.03). These findings demonstrate the potential of the device for accurately monitoring participants’ performance in lip and tongue pressure exercises during myofunctional therapy. The diversity of the training program (it mixed exercises mixed training games), its ability to provide direct feedback for each exercise to the participants, and the easy measurement of treatment adherence are major strengths of our training program. Conclusions The study’s portable device for home-based myofunctional therapy shows promise as a noninvasive alternative for reducing the severity of OSAHS, with a notable correlation between successful lip exercise improvement and AHI reduction, warranting further development and investigation.

Comparative analysis of two custom-made mandibular advancement devices with varied designs for treating moderate to severe obstructive sleep apnea

IntroductionCustom-made titratable mandibular advancement device (MAD) treatment can nowadays be considered a promising first-line treatment in patients with mild to severe obstructive sleep apnea (OSA). Specific manufacturing designs and titration mechanisms of MAD are on the market, characterized by their titration approach, vertical opening, and materials selection.The wing-designed MAD (SomnoDent® Flex™, SomnoMed Ltd, Sydney, Australia) has a lateral screw mechanism to advance the lower jaw in incremental steps of 0.1 up to 6.0 mm. The newer uniquely designed custom-made MAD with passive mouth closing (SomnoDent® Avant™ SomnoMed Ltd, Sydney, Australia) has a frontal exchangeable advancement strap of fixed lengths as a specific titration mechanism, all supporting freedom of lateral movement.We aimed to assess the associations between the type of MAD prescribed and OSA treatment outcome. MethodsData from 209 patients (165 male, mean age 53.9 (±10.9) years, median baseline BMI and AHI 27.02 [24.8; 29.7] kg/m2 and 22.8 [17.7; 31.6]/hour sleep, respectively) were collected.Of this cohort, 91 patients with the traditional, wing-based SomnoDent® Flex™ and 118 patients with SomnoDent® Avant™. All patients were diagnosed with a type 1 polysomnography demonstrating moderate to severe OSA (15 ≤ AHI ≤65 per hour sleep). The selected MAD was fitted in the so-called maximal comfortable protrusion.After 3 months of subjective titration until resolution of subjective symptoms and/or achieving physical limits, a checkup with validated home sleep monitoring was conducted. Treatment success was defined as “AHI reduction ≥50% with MAD compared to baseline AHI and AHI with MAD <10 events per hour”. ResultsThese real-world data set showed that 67% of patients achieved treatment success, with a statistically significant reduction in AHI from 22.8 [17.7; 31.6] to 7.45 [3.4; 15.0]/h sleep. The SomnoDent® Avant™ achieved 75% treatment success versus 56% for the traditional, wing-based SomnoDent® Flex™ (P < 0.05). Overall, AHI reduction was 70% for SomnoDent® Avant™ (P < 0.05) vs. 63% for SomnoDent® Flex™ (P < 0.05). ConclusionsThis study shows that choice of MAD design can impact the treatment outcome and could become an important consideration in selecting the type of MAD for personalized treatment for OSA patients. While the results of the traditional wing-based MAD design were comparable to the therapeutic outcome with other titratable, custom-made MADs, the MAD with the passive mouth closing feature showed significantly greater reduction in total AHI potentially due to encouraged nasal breathing, reduced mouth breathing and lesser vertical opening thereby decreasing the probability of tongue base collapse.

Efficacy of the ExVent Accessory for the O2Vent Optima Oral Appliance in the Treatment of Obstructive Sleep Apnea

Study Objectives: An optional accessory for the O2Vent Optima mandibular advancement device, the ExVent, provides oral expiratory positive airway pressure (EPAP). Similar to nasal EPAP, oral EPAP results in passive airway dilatation, reducing flow limitation. The present study was conducted to evaluate the safety and efficacy of the ExVent accessory for the treatment of mild to moderate obstructive sleep apnea (OSA). Methods: This prospective, multicenter, open-label, single-arm study enrolled participants diagnosed with mild to moderate OSA (defined as apnea–hypopnea index [AHI] 5–29). During the Home Use Phase, study participants logged their hours of O2Vent Optima + ExVent usage at home over 3 months. Participants were then evaluated by in-laboratory polysomnogram while using the O2Vent Optima + ExVent. The primary effectiveness measure was a change in AHI relative to baseline while using the O2Vent Optima + ExVent. Results: Treatment with the O2Vent Optima + ExVent improved AHI by 62% on average, from 15.3 (interquartile range [IQR]: 11.5–19.5) to 5.8 (IQR: 3.9–6.8; p&lt;0.001). Mean oxygen saturation improved from 93.5%±1.2% to 94.6%±1.34% (p=0.006). The lowest oxygen saturation increased from 85% (IQR: 83%–87%) to 90% (IQR: 89%–95; p&lt;0.001). The overall treatment success rate (AHI&lt;5) was 66%, and the treatment response rate (&gt;50% reduction in AHI) was 77%. No excessive adverse events or device malfunction events were reported. Conclusions: Use of the O2Vent Optima with the ExVent oral EPAP accessory successfully reduced AHI in mild to moderate OSA with no significant adverse effects.

Comparing efficacy of the mandibular advancement device after drug-induced sleep endoscopy and continuous positive airway pressure in patients with obstructive sleep apnea.

The purpose of this study was to compare objective and self-reported outcomes of two treatments for managing mild, moderate, and severe obstructive sleep apnea (OSA) in adults: a mandibular advancement device (MAD) and continuous positive airway pressure (CPAP). Patients diagnosed with OSA by means of polysomnography (PSG) included one group treated with a custom-made, two-piece, adjustable MAD and a second group treated with CPAP for 8weeks. Before the initiation of the treatment, all patients assigned to MAD underwent drug-induced sleep endoscopy (DISE), and all CPAP group patients underwent manual titration of CPAP after PSG. Objective (PSG) and self-reported (Epworth Sleepiness Scale [ESS] and Short Form Health Survey [SF-36]) data were used to assess outcomes. Collected data includedapnea-hypopnea index (AHI), mean capillary oxygen saturation (SpO2), oxygen desaturation index (ODI), arousal index (AI), degree of daytime sleepiness, and quality of life. A PSG follow-up after 8weeks with MAD in situ, and data from the CPAP data card were used to assess the effect of the two treatments. A total of 59 patients included 30 treated with MAD and 29 treated with CPAP.Between baseline and the 8-week follow-up, the mean AHI score decreased significantly from 35.1 to 6.8 episodes/h (p < 0.001) in patients treated with MAD and from 35.2 to 3.0 episodes/h (p < 0.001) in patients treated with CPAP. The mean AHI score at the 8-week follow-up was significantly lower in CPAP group than in MAD group (p = 0.003). The two groups did not differ significantly at follow-up regarding SpO2 (p = 0.571), ODI (p = 0.273), AI (p = 0.100), ESS score (p = 0.648), and SF-36 score (p = 0.237). In the short term, patients on CPAP attained better PSG outcomes in terms of AHI reduction. Both MAD after DISE evaluation and CPAP resulted in similar improvements in clinical symptoms and health-related quality of life, even in patients with severe OSA.

P070 Efficacy of the ExVent Accessory with the O2Vent Optima Oral Appliance in the Treatment of Obstructive Sleep Apnea – A Clinical Trial

Abstract Introduction The study assessed the efficacy of oral appliance device O2Vent Optima and ExVent, an oral Expiratory Positive Airway Pressure (EPAP) accessory in the treatment of OSA. Methods A prospective, open-label study conducted at 3 sites in mild to moderate OSA (AHI ≥ 5 and ≤ 30). Screening Phase A diagnostic in-lab PSG study confirmed a diagnosis of mild to moderate OSA. Treatment I Subjects used O2Vent Optima for 6 weeks and underwent a PSG sleep night while using the O2Vent Optima. Treatment II Subjects used O2Vent Optima + ExVent for 6 weeks and underwent a PSG sleep night while using the O2Vent Optima + ExVent Primary Effectiveness Measure: Change in AHI between baseline vs. O2Vent Optima MAD vs. O2Vent Optima + ExVent Results Treatment with Optima, Optima + ExVent reduced AHI from 22.5±6.4/hr to 12.6±4.5/hr to 5.9±2.7 (p&amp;lt; 0.005 baseline vs. Optima and Optima + ExVent; p&amp;lt;0.05 Optima MAD vs. Optima + ExVent). Average reduction in AHI with Optima was 43% and with Optima + ExVent was 72%. The lowest oxygen during sleep increased from 84.6±2.7% to 88.6±2.9% to 91.6±3.2% (p&amp;lt; 0.005 baseline vs. Optima and Optima + ExVent; p&amp;lt;0.05 Optima vs. Optima + ExVent). During the trial patients on treatment with Optima and Optima + ExVent demonstrated no excessive adverse events or device malfunction. Conclusion Treatment with O2Vent Optima and O2Vent Optima + ExVent significantly improved OSA compared to the baseline. Even greater benefit was observed with addition of ExVent to the Optima in mild to moderate OSA.

Weight loss induced alleviation of sleep-disordered breathing is associated with improvement of non-alcoholic fatty liver disease

IntroductionSleep-disordered breathing (SDB) and non-alcoholic fatty liver disease (NAFLD) are both common comorbidities in obese patients. Structured weight loss programs are effective and can reduce the incidence and severity of obesity-related comorbidities. The objective of the present analysis is to test whether weight loss induced alleviation of SDB is a predictor for improvement of NAFLD. MethodsObese participants underwent a standardized non-surgical 3 months weight reduction program (800 kilocalories per day with low carbohydrate and fat content). Abdominal sonography for NAFLD (grade 0 to 3) and monitoring for SDB (defined as apnea-hypopnea index [AHI] ≥ 15/h) were performed at baseline and after 3 months. Alleviation of SDB was defined as a shift from AHI≥ 15/h to <15/h. Results48 patients (48% female, age 42 ± 12 years, body-mass index 40.3 ± 8.1 kg/m2, AHI 14 ± 17/h, 85% NAFLD grade ≥1) participated in the weight loss program. In contrast to the no SDB group, in patients with SDB weight loss of 27.1 ±0 .9 kg (8.4 ± 2.8 kg/m2) after three months was paralleled by a reduction in AHI (-22 ± 17/h), prevalence of SDB (from 31% to 13%), and oxidized low-density lipoprotein (-13 ± 11 U/l). In individuals with preexisting SDB NAFLD grade improved more (2 versus 1, p<0.001) and was at a lower degree at 3 months than in those without SDB (0 versus 1, p = 0.015). In multivariable analysis models, SDB at baseline was associated with improvement of NAFLD grade (B 0.908; 95% CI 0.125, 1.691; p = 0.024), independently of age, sex, and BMI (each p>0.05, respectively). Decreasing BMI (B 0.16 [95%-CI 0.08; 0.23], p<0.001) and alleviation of SDB (B 0.90 [95%-CI 0.21; 1.58], p = 0.012) were independently associated with improvement of NAFLD grade. ConclusionPreexisting SDB and weight loss induced alleviation of SDB are predictors for improvement in NAFLD grade, independent of the extent of weight loss. SDB may contribute to the pathogenesis of NAFLD via SDB-induced oxidative stress and inflammation, but the causal mechanism remains unclear.

Adenotonsillectomy in Children with Obstructive Sleep Apnea Syndrome: Clinical and Functional Outcomes.

Adenotonsillectomy (AT) is the first-line treatment for pediatric obstructive sleep apnea syndrome (OSAS). Relatively few studies have evaluated the clinical and functional outcomes of AT in children with OSAS, but these studies show that surgery improves behavior and quality of life (QOL). However, residual OSAS after AT is reported in severe cases. This study aimed to retrospectively evaluate the clinical and functional outcomes of AT in a cohort of children with OSAS. We consecutively enrolled children with OSAS who underwent AT and were admitted to our clinic from 1 July 2020 to 31 December 2022. For each participant, medical history and physical examinations were performed. Before and after surgery, all patients underwent a standard polygraphic evaluation, and caregivers completed the OSA-18 questionnaire. A total of 65 children with OSAS, aged 2-9 years, were included. After AT, 64 (98.4%) children showed a reduction in AHI, with median (IQR) values decreasing from 13.4/h (8.3-18.5/h) to 2.4/h (1.8-3.1/h) (p-value < 0.0001). Conversely, median (IQR) SpO2 nadir increased after surgery from 89% (84-92%) to 94% (93-95%) (p-value < 0.0001). Moreover, 27 children (18%) showed residual OSAS. The OSA-18 score decreased after AT from median (IQR) values of 84 (76-91) to values of 33 (26-44) (p-value < 0.0001). A positive significant correlation was found between OSA-18 post-operative scores and AHI post-operative scores (rho 0.31; p-value = 0.01). Our findings indicate that, in children with OSAS, AT is associated with significant improvements in behavior, QOL, and polygraphic parameters. However, long-term post-surgical follow-up to monitor for residual OSAS is highly recommended, especially in more severe cases.

Three-Dimensional Airway Changes and AHI Reduction Following Maxillomandibular Advancement and Genioglossus Advancement in Patients with Obstructive Sleep Apnea

Three-Dimensional Airway Changes and AHI Reduction Following Maxillomandibular Advancement and Genioglossus Advancement in Patients with Obstructive Sleep Apnea

Effectiveness of Narval CC™ device in the treatment of obstructive sleep apnea

Mandibular advancement devices (MAD) are used in sleep apnea with varying results. We aimed to examine whether or not a MAD should be an integral treatment modality in the care of our patients with obstructive sleep apnea.We designed a feasibility study and included 32 patients after meeting inclusion criteria. Only 3 patients did not finish the second sleep study exam. The intervention was an individually designed MAD and a sleep study exam was performed prior and post treatment. The outcome objective was an apnea-hypopnea index of under 10 and with a 50% reduction.Patient population had a baseline AHI of 19.0 and mean reduction of AHI with MAD treatment to 13.3 yielding a MAD efficacy rate of 31% when outcome objectives were applied. The average reduction in AHI was 24.8% with 9 of the 29 patients actually experiencing an increase in AHI with MAD treatment. When there was a reduction in AHI using the MAD device the AHI reduction rate was 49.1% and there was a tendency for better treatment outcome when apnea-hypopnea was predominantly supine.A mandibular advancement device serves as an important treatment modality in the care of patients with obstructive sleep apnea due to patient satisfaction and compliance. The broad range of treatment response to our MAD device highlights the importance of performing a sleep study exam after initiation of treatment with a MAD but also illustrates the complexity and need for individually tailored treatment for patients with obstructive sleep apnea.

0570 Use of the ExVent Accessory with the O2Vent Optima Oral Appliance for the Treatment of Obstructive Sleep Apnea – A Clinical Trial

Abstract Introduction The ExVent is an optional accessory to the O2Vent Optima mandibular advancement device (MAD) and provides oral Expiratory Positive Airway Pressure (EPAP). Oral EPAP with the ExVent is designed to provide upper airway support via similar mechanisms of action of nasal EPAP devices in commercial distribution, e.g., passive dilatation of the airway, which reduces flow limitation. Nasal EPAP devices are in commercial distribution as stand-alone therapies for the treatment of OSA. The oral EPAP provided by the ExVent accessory is designed to augment the OSA therapy provided by the O2Vent Optima. Methods This is a prospective, open-label, single-arm study conducted at 3 sites. Subjects who have been diagnosed with mild to moderate OSA (i.e., AHI ≥ 5 and ≤ 30) were included. Screening Phase The subjects completed a PSG study to obtain the baseline AHI and confirm a diagnosis of mild to moderate OSA Home Use Phase Subjects used the O2Vent Optima + ExVent for up to 3 months and logged usage hours. Subsequent to the Home Use Phase subjects underwent an in-lab PSG sleep night while using the O2Vent Optima + ExVent. Primary Effectiveness Outcome Measure: Change in AHI between baseline and the AHI measured during the in-lab PSG sleep night using O2Vent Optima + ExVent. Safety Outcome Measure: Adverse events will be summarized descriptively in terms of type and frequency Results Patients with mild to moderate OSA were treated with Optima MAD and ExVent for 3 months at 3 different sites in North America. Preliminary data analysis demonstrated that treatment with Optima MAD and ExVent reduced AHI from 13.5±6.4/hr to 6.6±4.5/hr (p&amp;lt; 0.05), average 58% reduction in AHI. The lowest oxygen during sleep increased from 84.6±2.7% to 88.6±2.9% (p&amp;lt; 0.05). Overall success rate (&amp;gt;50% reduction in AHI) with treatment was 80%. During the trial patients on treatment with Optima MAD and ExVent demonstrated no excessive adverse events or device malfunction. Conclusion The clinical trial confirmed successful treatment with combined use of O2Vent Optima MAD and oral Expiratory Positive Airway Pressure accessory - ExVent in patients with mild to moderate OSA. Treatment was well tolerated with no excessive adverse effects. Support (if any)

0451 Dronabinol Plus Acetazolamide for the Treatment of Obstructive Sleep Apnoea: A Proof of Concept and Mechanistic Exploration Study

Abstract Introduction Current treatments for obstructive sleep apnoea (OSA) typically target the anatomical pathophysiological endotype and are either not tolerated or effective in a significant proportion of patients. Pharmaceuticals may provide an alternative therapeutic option and may address some or all of the remaining endotypes (loop gain, muscle compensation and arousal threshold). This randomised, double-blind, placebo-controlled, cross-over study examined the effect of combination acetazolamide and dronabinol (IHL-42X) at low, medium and high doses on OSA severity and the OSA endotypes. Methods Participants with OSA (apnoea-hypopnoea index; AHI≥15events/hr) received 1-week of IHL-42X at each of the 3 doses and 1-week of placebo, each separated by 1-week washout. The change from baseline in AHI, oxygen desaturation index (ODI), Epworth sleepiness score (ESS), and mood (profile of mood states) on the final night of each treatment arm relative to placebo were the major endpoints. Adverse events (AEs) were monitored throughout. Exploratory analyses examined the change in OSA endotypes determined from polysomnography from baseline values. Results Ten of 11 participants (mean baseline AHI 40.7events/hr) completed the final night of at least one treatment arm. All doses of IHL-42X demonstrated a significant reduction in AHI from baseline when compared with placebo (low, -19.7±27.1; medium, -17.5±23.3; high, -16.4±23.8 versus placebo, -2.8±21.0events/hr; all p&amp;lt; 0.05). The change from baseline in ODI3% at the low, medium and high doses of IHL-42X (-15.2±24.8; -15.4±19.0 and -8.3±13.2events/hr, respectively) were not significantly different from placebo (-2.8±21.0events/hr). IHL-42X did not significantly alter ESS or mood. No serious AEs occurred. However, 31 mild-moderate possibly, probably or treatment related AEs occurred during IHL-42X dosing (4 at the low dose) and 4 occurred during placebo. Relative to baseline, loop gain decreased by 15, 21 and 20% (Cohen’s d all ≥0.59) at the low, medium and high doses, respectively, and collapsibility improved by 12.5% (d=1.06) at the low dose only. Conclusion One week of nightly IHL-42X at all doses was well tolerated, safe and associated with significant reductions in OSA severity. IHL-42X may act to reduce OSA severity by decreasing loop gain and upper airway collapsibility, particularly at the low dose. Support (if any) Incannex Healthcare Ltd supported this study.

0473 Multi-outcome of mandibular advancement device in Obstructive Sleep Apnea with different polysomnographic phenotype

Abstract Introduction The association of mandibular advancement device (MAD) treatment response and polysomnographic phenotype in patients with obstructive sleep apnea (OSA) has not been fully elucidated. We hypothesized MAD response would be associated with two polysomnographic phenotypes, including sleep stage and positional dependency in treatment-naïve patients with moderate-severe obstructive OSA. Methods This retrospective study recruited OSA patients with AHI ≥15/h, aged 20 to 80, treatment naïve, and received MAD treatment for more than three months. Positional phenotype included supine predominant (supine-p) and non-positional OSA. Sleep stage phenotype included REM-predominant (REM-p), NREM-predominant (NREM-p), and stage-independent (SI) OSA. MAD response was defined as criterion 1: residual AHI&amp;lt; 5/h with &amp;gt;50% reduction, and criterion 2: residual AHI&amp;lt; 10/h with &amp;gt;50% reduction. Outcomes included the change in PSG parameters, habitual latency of sleep onset and sleep hour, Epworth sleepiness scale, excessive daytime sleepiness, depression, physical, vitality and mental health domain of SF-36, and in-lab bedtime and wake blood pressure (BP). Results 379 patients with median age of 52.2 years, BMI of 26 kg/m2, 78.1% of men, and AHI of 28.2/h were recruited. Supine-p and REM-p OSA had lower baseline AHI and desaturation. The overall response rate were 34.7% (criterion 1 ) and 56% (Criterion 2). Supine-p OSA had higher response rate than non-positional OSA (criterion 1: 42.2% vs. 20.3%; criterion 2: 64.3% vs. 32.5%), while NREM-p OSA had lower response rate than REM-p and SI (REM-p vs. NREM-p vs. SI: criterion 1: 43.9% vs. 9.7% vs. 34.2%; criterion 2: 54.5% vs. 41.9% vs. 53.3%). Despite the more reduction in AHI, desaturaiotn, and arousal in responders, there was no differences in change of ESS, EDS, sleep pattern, depression, SF 36 domain, and BP between responders and non-responders which remained unchanged after stratified with sleep stage and position phenotypes. Conclusion Non-positional and NREM-predominant OSA had lower responses rate to MAD treatment. There were no differences in non-breathing outcomes between responders and nonresponders regardless of sleep stage and positional phenotype. Support (if any) The work was supported by grants from the National Science and Technology Council, Taiwan (NSTC 111-2314-B-002-293); Ministry of Science and Technology, Taiwan (MOST 109-2314-B-002-252); National Taiwan University Hospital (NTUH 107-19, 111-X0033, 111-S0298)

0494 Early Feasibility Study on Use of Noninvasive Temporal Interference Stimulation of the Hypoglossal Nerve in the Treatment of OSA

Abstract Introduction Hypoglossal nerve stimulation has proven effective as an alternative to Positive Airway Pressure (PAP) machines in treating obstructive sleep apnea (OSA). The only currently FDA-approved hypoglossal nerve stimulator requires surgical implantation. Somnial Inc. is developing a noninvasive nerve stimulator based on temporal interference (TI), such that multiple supra-kHz-modulating electrical fields overlap to create a hyper-localized field modulating at a lower, nerve-stimulating frequency equal to the offset between the original fields. Bilateral stimulation reduces lateral movement of the tongue and requires less energy applied to the individual nerves. In early studies, transcutaneous, bilateral TI stimulation showed strong forward and central tongue movement with long-term tolerability. Methods To determine the clinical impact of TI on the treatment of OSA, 11 patients recently diagnosed with moderate to severe OSA (AHI 15-50/hour) based on in-lab polysomnography (PSG) and BMI &amp;lt; 35 were subjected to bilateral TI stimulation of the hypoglossal nerves during another PSG. Two pairs of electrodes were placed on either side, medial to the inferior aspect of the mandible overlying the genioglossus muscle. The frequencies were modulated in a 4-second-on, 2-second-off pattern. Initial power settings were determined as sufficient to move the tongue without discomfort and were increased throughout the night in an approach similar to a CPAP titration study. Results 5 of the 11 patients analyzed in the study, including 4 out of 4 women, responded to the therapy (AHI reduction from baseline by &amp;gt;50% and an AHI of &amp;lt; 20/hour). Patient questionnaires indicate the treatment was well tolerated throughout the night. Conclusion These promising proof of concept results after a single night indicate the potential for the use of TI in the treatment of OSA. Transcutaneous application of stimulation energy via TI energy could be used to determine the efficacious does required to reduce AHI events in the at-home healthcare setting. This justifies future research in long-term, chronic-treatment studies with TI stimulation and the advancement of a home-based device. Support (if any)