0453 3-Year Outcomes of Proximal Hypoglossal Nerve Stimulation in the THN3 Controlled Trial

Abstract

Abstract Introduction The THN3 randomized, controlled trial of moderate to severe obstructive sleep apnea (OSA) showed that proximal (“targeted”) hypoglossal nerve stimulation (HGNS) safely improved sleep-disordered breathing (SDB) and quality of life (QOL) through 11 months of treatment. Outcomes of subjects receiving active proximal HGNS also surpassed those with inactive therapy 4 months post-implant. Herein 3-year outcomes of THN3 are reported and compared to distal HGNS (STAR trial). Methods THN3 OSA subjects (Apnea-Hypopnea Index, AHI, 20-65/hr; BMI ≤ 35 kg/m2, no drug-induced sleep endoscopy screening) were followed long-term. Complete data through 3-year follow-up were analyzed. Efficacy measures comprised AHI, Oxygen Desaturation Index (ODI), %sleep time O2 saturation < 90% (T90), Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ) EQ-5D Visual Analog Scale (VAS) and Snore Outcomes Survey (SOS). 36-Month medians were compared against those after 11 months of therapy (Month 12/15) and with STAR. Adverse events (AEs) during Months 12-36 for THN3 and STAR were also compared. Results 75% of THN3 participants (104/138) attended 3-year follow-up, with complete efficacy records in N≥93 except for SOS (N=67, not administered at all sites). Proximal HGNS produced clinically and statistically significant improvements in SDB and QOL at Month 12/15 that were closely maintained at 36 Months (median paired changes at Month 36 from Baseline/Month 12/15: □AHI:-18.2/-0.1, □ODI:-16.2/0.8, □T90:-1.8/0.2, □FOSQ:3.0/0.0, □ESS:-5.0/0.0, □VAS:5.0/0.0, □SOS:37.5/3.1) and were comparable to STAR at 36 Months (□AHI:-19.4, □ODI:-17.2, □T90:-1.5, □FOSQ: 2.6, □ESS:-4.0). Procedure- and device-related AEs respectively totaled (3 and 27)/(4 and 122) in THN3/STAR over Months 12-36. During this time, 3 severe related-AEs occurred in THN3; the most frequent related AEs involved tongue discomfort (N=8, device-related). Conclusion Improvements in sleep apnea and QOL on proximal HGNS at Month 12/15 persisted through at least Month 36. Proximal HGNS long-term efficacy was comparable to distal HGNS. AEs occurred uncommonly during long-term follow-up and were typically mild. Proximal HGNS is a safe, effective, stable, long-term therapy, yielding comparable improvements to distal HGNS in treating moderate to severe OSA. Results of the ongoing, confirmatory OSPREY randomized controlled trial will provide additional insights into therapeutic benefits of proximal HGNS. Support (if any) LivaNova