Matched Clinical Outcomes of Inspire V vs. Inspire IV Hypoglossal Nerve Stimulation: A Pilot Study

Introduction: The Inspire V hypoglossal nerve stimulation (HGNS) system for treatment of obstructive sleep apnea (OSA) integrates the respiratory sensor into the implantable pulse generator. Industry data show this simplification decreases surgical times compared to Inspire IV, while maintaining safety, therapeutic effect, and adherence. It is unknown whether this change improves clinical outcomes.

Methods: In this ongoing study, we performed a preliminary matched cohort analysis on patients undergoing HGNS for OSA between 2015-2026. Patients implanted with the novel Inspire V (May-Dec 2025) were matched to Inspire IV controls from an institutional set of 736 patients by exact matching sex and VOTE scores and propensity score matching for age, body mass index (BMI), and preoperative apnea hypopnea index (AHI). Changes in objective AHI and Epworth Sleepiness Scale (ESS) with HGNS were compared between Inspire V patients and matched controls via Wilcoxon signed-rank tests and rank-biserial correlations (rrb).

Results: 15 Inspire V patients had analyzable follow-up data, 14 of whom were able to be matched to 14 controls per the above protocol. On average, patients were older (66.9±9.6 years), overweight (BMI 28.9±2.9 kg/m2), males (71.4%) with moderate OSA (AHI: 27.8±11.3 events/hr). Though not statistically significant, there was a larger average percent reduction in AHI (-54.5±34.3% vs. -46.4±36.6%, p=0.45, rrb=0.24, n=14) and improvement in ESS scores (-3.8±5.1 vs 0.5±4.7 units, p=0.41, rrb=0.47, n=5) in the Inspire V cohort.

Conclusions: This ongoing pilot study suggests that Inspire V implantation may offer improved clinical outcomes over Inspire IV in matched patients. As more patients complete the post-implant follow-up protocol, superiority/equivalence of outcomes can be better elucidated.