Sustained Therapeutic Benefits for 3 Years in the THN3 Randomized, Controlled Trial of Targeted Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

Rationale The THN3 randomized, controlled trial demonstrated that targeted hypoglossal nerve stimulation (THN) was associated with substantial improvement in sleep-disordered breathing over 11 months of therapy in moderate to severe obstructive sleep apnea (OSA) with a favorable safety profile. Subjects receiving THN fared significantly better than control patients with inactive THN. This investigation shall describe the 3-year safety and efficacy results from THN3.

Methods 138 Subjects with moderate to severe OSA (apnea-hypopnea index, AHI, 20-65/hr; BMI ≤ 35 kg/m2) were enrolled in THN3. Participants with complete datasets through the pre-specified 3-year visit were analyzed. Efficacy outcomes included respiratory parameters, daytime sleepiness, quality of life, and snoring.

Results 103 THN3 subjects completed 3-year follow-up. Clinically and statistically significant improvements achieved after 11 months of therapy were maintained at Months 24 and 36 in sleep disordered breathing (Median: AHI from 36.5 reduced by 14.9, 15.9, and 18.2; ODI from 36.4 reduced by 15.4, 13.3, and 16.2; T90 from 9.9 reduced by 3.8, 1.4, and 1.8, n=93), sleepiness (Median ESS from 12.0 reduced by 5.0, 5.0, and 5.0, n=97), quality of life (Median FOSQ from 15.0 increased by 2.8, 3.3, and 3.0, n=95), and snoring (Median SOS from 21.9 increased by 35.4, 37.5, and 37.5, n=67). 3 and 27 adverse events in 3 and 22 subjects were related to the procedure and device, respectively, during Months 12-36; 3 were severe.

Conclusions Therapeutic benefits achieved at 11 months of therapy in THN3 were maintained for 3 years. Adverse events were infrequent and mild during long-term follow-up. Therefore, THN therapy is a safe, effective, and stable long-term treatment for moderate to severe OSA.

Publication History

Article published online:
12 May 2023