Clinical Severity Staging System and Response to Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

While hypoglossal nerve stimulators (HGNS) have been shown to be associated with reduced apnea-hypopnea index (AHI) scores in many continuous positive airway pressure-intolerant patients with obstructive sleep apnea (OSA), it is not effective for all patients, and it is unclear who would benefit most.

To explore baseline factors associated with response to HGNS and create a prognostic stratification system.

This retrospective cohort study included patients with OSA who underwent implant with an HGNS from April 2019 to October 2023 at a single tertiary care center and received a postimplant sleep study. During that time, 194 patients underwent HGNS implant. Data were analyzed from February 2024 to April 2024.

HGNS implant and sleep study.

Response according to the modified Sher criteria (>50% reduction in AHI score and AHI <15 postimplant).

Among the 119 patients included, the median (range) age was 63 (33-79) years, and 36 (30%) were female. Of the 119 included, 83 (70%) were responders. Neck size, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), AHI score, and comorbidity burden were associated with response and used to create a 4-category clinical severity staging system. Patients with small necks (≤14 inches for women or ≤16 inches for men), a BMI of less than 30, and an AHI score of 30 or less had the highest response rate (11 [91%]). Patients with large necks (>14 inches for women or >16 inches for men), a BMI of 30 or greater, an AHI score of 30 or greater, and comorbidities had the lowest response rate (16 [38%]). The staging system had moderate discriminative power, with a C statistic of 0.68 (95% CI, 0.57-0.78).

The results of this cohort study suggest that neck size, BMI, AHI score, and comorbidity burden are 4 clinically relevant and easily obtainable values that are associated with response to HGNS. While this staging system may help physicians identify patients who are most likely to benefit from implant, these results need to be validated in a separate cohort.