Proximal Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea in the OSPREY Study : A Randomized Controlled Trial.

BACKGROUND

Hypoglossal nerve stimulation (HGNS) is used to treat obstructive sleep apnea (OSA); however, evidence is limited for patients who cannot tolerate positive airway pressure therapy. Proximal HGNS (pHGNS) provides multicontact stimulation of proximal nerve portions, with easier electrode implantation than distal nerve stimulation.

OBJECTIVE

To evaluate the efficacy and safety of pHGNS in patients with moderate-to-severe OSA.

DESIGN

7-month randomized controlled trial followed by a 6-month open-label extension. (ClinicalTrials.gov: NCT04950894).

SETTING

23 U.S. health centers.

PATIENTS: Adults aged 22 years or older with moderate-to-severe OSA.

INTERVENTION: All patients underwent implantation with pHGNS at baseline and were randomly assigned in a 2:1 ratio to treatment or control. Therapy began at month 1 (treatment) or month 7 (control).

MEASUREMENTS: Assessments included the proportion of patients achieving greater than 50% improvement from baseline in the apnea-hypopnea index (AHI) and AHI below 20 events/h at month 7 (primary end point), improvements in oxygen desaturation index (ODI) and patient-reported outcomes (for example, Epworth Sleepiness Scale [ESS]), and safety.

RESULTS

The 104 randomly assigned patients had a mean age of 55.6 years (SD, 9.0), body mass index of 30.6 kg/m2 (SD, 3.0), a preimplantation AHI of 35.7 events/h (SD, 12.8), and a preimplantation ODI of 36.7 events/h (SD, 13.4). At month 7, 58.2% (95% CI, 45.5% to 70.2%) of patients assigned to treatment (n = 67) versus 13.5% (CI, 4.5% to 28.8%) assigned to control (n = 37) achieved the primary end point, and ODI was reduced by at least 25% in 68.7% (CI, 56.2% to 79.4%) versus 37.8% (CI, 22.5% to 55.2%) of patients, respectively. Median ESS score improved from baseline to month 7 in the treatment group (10.0 [IQR, 7.0 to 14.0] to 6.0 [IQR, 5.0 to 9.0]) but not in the control group (9.0 [IQR, 7.0 to 11.0] to 9.0 [IQR, 6.0 to 11.0]). No serious procedure-related adverse events were reported.

LIMITATIONS: Lack of blinding, small sample size, and short follow-up.

CONCLUSION

pHGNS for OSA yielded clinically significant responses versus control at month 7, supporting pHGNS as a therapeutic option for OSA.

PRIMARY FUNDING SOURCE: LivaNova PLC.