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Upper Airway Pacing for Obstructive Sleep Apnea. Charles W. Atwood, Jr., MD, FCCP, FAASM Assoc Professor of Medicine University of Pittsburgh Sleep Program Director, VA Pittsburgh Healthcare System. Disclosure: Charles W. Atwood, Jr., MD. Research Support Federal NIH, NIDDK - OSA
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Upper Airway Pacing for Obstructive Sleep Apnea Charles W. Atwood, Jr., MD, FCCP, FAASM Assoc Professor of Medicine University of Pittsburgh Sleep Program Director, VA Pittsburgh Healthcare System
Disclosure: Charles W. Atwood, Jr., MD Research Support Federal NIH, NIDDK - OSA Dept of Defense – Lung cancer Industry Research Grant Philips-Respironics, Inc. Forest Research Institute Industry advisory Philips-Respironics Carecore National
Outline • Background • Upper Airway Stimulation • STAR Trial • Conclusions
Pathogenesis of Obstructive Sleep Apnea Promotion of Airway Patency Promotion of Airway Collapse Negative pressure on inspiration Pharyngeal dilator Muscle contraction (genioglossus) • Extralumenal positive • Pressure • Fat Deposition • Small mandible Lung volume (longitudinal traction) Risk Mediated by a: Gene (Obesity, Craniofacial Structure, Respiratory Control / Environment (Obesity) Interaction AJRCCM 2005 172:1363–1370
Sleep Disordered Breathing and Mortality: Eighteen-Year Follow-up of the Wisconsin Sleep Cohort(n = 1396) • SDB, irrespective of EDS, was associated with increased mortality. • The striking high CV mortality risk in untreated severe SDB, suggests that SDB Rx should not be contingent on daytime sleepiness symptoms Sleep 2008 31:1071-78
Increased Prevalence of Sleep-Disordered Breathing in Adults • The current prevalence estimates of moderate to severe sleep-disordered breathing (apnea-hypopnea index, measured as events/hour, ≥15) are: • 10% (95% CI: 7, 12) among 30–49-year-old men • 17% (95% CI: 15, 21) among 50–70-year-old men • 3% (95% CI: 2, 4) among 30–49-year-old women • 9% (95% CI: 7, 11) among 50–70 year-old women • These estimated prevalence rates represent substantial increases over the last 2 decades - relative increases of between 14% and 55% depending on the subgroup Am J Epidemiol. 2013;177(9):1006–1014
OSA and Cardiovascular Disease • Primary HTN: 35% prevalence • Drug-resistant HTN: 65 to 80% prevalence • Most common secondary cause • Coronary Artery Disease: 30% prevalence • Heart failure: 21-37% prevalence • Atrial Fibrillation: OSA present 5 X more likely • Stroke: 60% prevalence Circulation2012;126:1495-1510
Long-term cardiovascular outcomes in men with OSA AIM: Observational study to compare incidence of fatal and non-fatal cardiovascular events in simple snorers, patients with untreated OSA, patients treated with CPAP, and healthy men recruited from the general population. Design:Prospective observational cohort. 264 healthy men, 377 simple snorers, 403 with untreated mild-moderate OSA (AHI 5-30), 235 with untreated severe OSA (AHI > 30), and 372 with OSA and treated with CPAP Cumulative Incidence of Fatal CV Events Cumulative Incidence of Non-fatal CV Events Months Months Conclusion:In men, severe OSA significantly increases the risk of fatal and non-fatal cardiovascular events. CPAP treatment reduces this risk. Lancet 2005 365: 1046–53 .
CPAP Therapy and Adherence PAP therapy when used consistently results in decreased daytime sleepiness*, improved HRQOL, and decreased vascular risk. Recent studies of CPAP therapy investigated adherence: • APPLES Study – largest RCT in sleep medicine to date (1,516 subjects enrolled) and CPAP adherence rate was 39% at 6-months use of CPAP therapy (174 of 443) • Home PAP Study – Evaluation of standard OSA care vs. home-base diagnostics and titration. Results of 3-month follow-up: CPAP adherence was 39% (Lab titration); CPAP adherence was 50% (Home titration) Conclusion: • CPAP is first-line therapy and effective when consistently used by OSA patients. • Alternative therapy options for moderate or severe OSA patients who are nonadherent to PAP are desirable
OSA Value of Selected Treatment Options • Darker more valuable. Only Positive Airway Pressure (PAP) and Surgery indicated for patients with Moderate or Severe OSA Upper Airway Stimulation therapy treatment indication http://www.sleepapnea.org/diagnosis-and-treatment/treatment-options.html
Outline • Background • Upper Airway Stimulation • STAR Trial • Conclusions
The Inspire System: Built on a proven, commercial grade technology platform Stimulation Lead - Self sizing cuff - Multiple stimulation vectors Implanted Pulse Generator (IPG) - 6-8 year projected longevity Effort Sensor - Secure, stable location - Direct measurement of ventilatory effort - Short surgical tunnel
Upper Airway Anatomy & Stimulation Site Superior Longitudinal Styloglossus (SG) Inferior Longitudinal Hyoglossus (HG) Stimulation Site: Medial branch of the hypoglossal nerve, activates only protrusors (genioglossus, geniohyoid), distal to retractors (styloglossusand hyoglossus) Geniohyoid (GH) Thyrohyoid Superior root of ansacervicalis Genioglossus (GG) Stimulation Site Hypoglossal Nerve (XII)
Upper Airway Stimulation • Device Programmer • Adjust Therapy Parameters • Bluetooth enables remote adjustments • during titration studies in the sleep lab • Patient Programmer • Turn therapy ON/OFF • Adjust amplitude • No airway anatomy alteration • Works with patients physiology • Standardized implant technique • Fast post op recovery
Basic Therapy Parameters Onset Expiratory Inspiratory Sensor Signal Offset Stimulating Pulses • Amplitude (V) – primary stimulation strength adjustment • Rate (Hz) – default 33 Hz • Pulse Width (µsec)– default 90 µsec
Upper Airway Stimulation advances tongue to open airway Tongue Advanced STIMULATION ON Airway Obstructed STIMULATION OFF Tongue base Epiglottis Tongue base Tongue base advancement with stimulation Observed during sleep endoscopy
Effect of stimulation on the Retropalatal and Retrolingual airway area between awake endoscopy and DISE Eur Respir J 2014; in press
Increases in retropalatal and retrolingual area comparing no stimulation with progressively higher levels of stimulation during DISE No stimulation First sensation Bulk movement Titrated therapeutic Sub-discomfort Retropalatal Retrolingual Eur Respir J 2014; in press
PSG: Effect of Stimulation EEG EMG Nasal Pressure Thermo Chest Abdomen SpO2 30 seconds Therapy OFF Therapy ON
In-lab PSG Titration Algorithm Arousal Threshold ≥ 30 minutes in the patient’s preferred sleep position with minimum occurrence of events, preferably with REM sleep observed Therapeutic Amplitude Range Amplitude (volts) Reduce amplitude by 0.1 to 0.2 volts if stimulation causes persistent arousals or is poorly tolerated ≥ 10 min Increase amplitude by 0.1 to 0.2 volts if ≥ 5 obstructive apneas or hypopneas or loud, unambiguous snoring Start: 0.2 V below Functional Threshold Time (minutes) *Adapted from current practice guidelines established for CPAP titration by the American Academy of Sleep Medicine, ref: Journal of Clinical Sleep Medicine, Vol. 4, No 2, 2008
Clinical Trial Experience • Feasibility Trial • Proof of Principle Trial • 34 patients • 8 Centers • Completed in 2010 • Demonstrated safety and patient selection • References: • Operative technique in otolaryngology-head and neck surgery. 2012 23(3): 227-33 • Journal of Clinical Sleep Medicine 2013 9 (5) 433-438 • The Laryngoscope 2012 122(7): 1626-33 • 8 patients • 4 Centers • Completed in 2001 • Demonstrated therapy concept Reference: Arch Otolaryngol Head Neck Surg2001 127:1216-1223
Examples collapse at the level of the palate during DISE Concentric collapse Anteroposterior collapse • JCSM 2013 9 (5) 433-438
Inspire UAS effect during DISE Palate Therapy OFF Palate Therapy ON P P Posterior oropharyngeal wall Reference: 2 slices L R R L Palate Posterior Uvula Tongue-Base TongueBase Therapy ON Tongue Base Therapy OFF P P Epiglottis R L L R Lingual Tonsils
Outline • Background • Upper Airway Stimulation • STAR Trial • Conclusions
Stimulation Therapy for Apnea Reduction (STAR Trial) ClinicalTrials.gov NCT01161420 Hypothesis: Unilateral Stimulation of the Hypoglossal Nerve during sleep will safely and effectively treat Obstructive Sleep Apnea NEJM 2014 370:139-49
Outcome Measures: Baseline vs. 12-Months • Co-Primary • Apnea Hypopnea Index • Oxygen desaturation index (ODI4%) • Secondary • Epworth Sleepiness Scale • Functional Outcomes of Sleep Questionnaire • SaO2 < 90% NEJM 2014 370:139-49
Methods I • Prospective, multicenter trial with randomized therapy withdrawal armin participants with moderate to severe OSA who had failed or had not tolerated CPAP. • All underwent a screening polysomnographic (PSG) study, surgical consultation, and drug-induced sedation endoscopy (DISE). • Participants without complete concentric collapse at the retropalatal airway received an implanted neurostimulator NEJM 2014 370:139-49
Inclusion Criteria • AHI between 20 and 50 • Have failed or have not tolerated CPAP • Central and mixed sleep apnea accounted for < 25% of all AHI events • Absence of significant apnea when sleeping in a non-supine position (AHInon-supine> 10) NEJM 2014 370:139-49
Exclusion Criteria • BMI > 32 • Neuromuscular diseases • Severe Co-Morbid Cardiopulmonary Disease • Other chronic sleep disorders • Complete concentric collapse at the level of soft palate during drug-induced sedation endoscopy (DISE) NEJM 2014 370:139-49
Examples collapse at the level of the palate during DISE Concentric collapse Anteroposterior collapse • JCSM 2013 9 (5) 433-438
Methods II • Participants were followed for 12 months to assess efficacy and adverse events. • PSG (AHI and ODI) • Quality of life measures • Epworth Sleepiness Scale (ESS) • Functional Outcomes of Sleep Questionnaire (FOSQ) • Responders after 12 months of continuous therapy were randomized to one week of therapy suspension (OFF) vs.therapy maintenance (ON) and evaluated with PSG. NEJM 2014 370:139-49
Consort Flow Chart NEJM 2014 370:139-49
p < 0.0001 p < 0.0001 Primary Outcome Measures: AHI and ODI (n = 124) AHI ODI • 68% reduction in AHI from baseline to Month-12 • 70% reduction in ODI from baseline to Month-12 *Median and error bar in standard error NEJM 2014 370:139-49
p < 0.0001 p < 0.0001 Secondary Outcome Measures: FOSQ & ESS (n = 123) ESS Scale FOSQ Score *Median and error bar in standard error NEJM 2014 370:139-49
Secondary Outcome Measure: SaO2 < 90% p < 0.05 NEJM 2014 370:139-49
p = n.s. p < 0.0001 Randomized Controlled Therapy Withdrawal *mean and error bar in standard error NEJM 2014 370:139-49
Relevant Adverse Events • Serious:Device related • 1%Device revision • Non Serious: Procedure related • ~ 25% Pain (minimal, most did not require narcotics - substantially less than UPPP) • Non-Serious:Devicerelated • ~ 33% Tongue discomfort / abrasion (time limited) • 1% Mild or Mod Infection (cellulitis) * One Death Unrelated to the Trial NEJM 2014 370:139-49
Adherence Data • After 12 months follow up of 126 implanted participants, 124 participants (98%) remained active users of UAS therapy. • One participant died unexpectedly due to an unrelated cause, and one participant requested a device removal for personal reasons. • Based on self reports from 123 participants at 12 months, 86% (106 of 123) used the device daily and 93% (115 of 123) used the device at least 5 days a week. • The UAS device registers the cumulative hours of stimulating pulses duration since last device interrogation. At the 12-month visit, the average stimulation pulses time was 2.6 hours per night. • The stimulating pulses were not delivered continuously during sleep, and were only delivered during the late expiratory and inspiratory phases of respiration. NEJM 2014 370:139-49
Measurement of Use of Therapy NEJM 2014 370:139-49
Upper Airway Stimulation effect on Sleep NEJM 2014 370:139-49
REM vs. NREM Sleep NEJM 2014 370:139-49
Other Outcome Measures NEJM 2014 370:139-49
Outline • Background • Upper Airway Stimulation • STAR Trial • Conclusions
Conclusions • The STAR Pivotal Trial provided definitive evidence that upper airway stimulation is safe and effective in participants with moderate to severe OSA • Upper Airway Stimulation can play a significant role in the management of properly selected “at risk” patients who do not accept or adhere to CPAP therapy
NATURE 2010 463: 258-259 Thank You University of Pittsburgh / CTSI / Clinical + Translational Science Institute