Therapeutic Positive Airway Pressure Level Predicts Response to Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

Study Objectives: To determine whether therapeutic positive airway pressure (PAP) level predicts response to hypoglossal nerve stimulation (HGNS) for obstructive sleep apnea using the coprimary outcomes of apnea-hypopnea index (AHI) and 4% oxygen desaturation index. Methods: Combined cohort study from two US sleep otolaryngology training programs. Subjects were adults with AHI > 15 events/h who underwent HGNS. Eligible subjects had diagnostic preoperative sleep studies, full-night efficacy postoperative studies and therapeutic PAP levels available for analysis. Low and high PAP groups were compared using the t test for continuous variables and chi-square test for categorical variables. Results: Fifty-six patients met all inclusion criteria. On average, patients were male, Caucasian, middle-aged, and overweight. Thirteen patients were in the low PAP group (< 8 cm H2O) and 43 patients in the high PAP group (< 8 cm H2O). Although both groups experienced improvement of polysomnographic measures with HGNS, the low PAP group achieved a significantly larger mean AHI reduction (36.7 +/- 22.7 versus 18.4 +/- 23.4, P = .02). Additionally, the low PAP group had a greater response rate (defined as AHI < 20 events/h and > 50% reduction of AHI) than the high PAP group (92% versus 44%, P < .01). Conclusions: Therapeutic PAP level may aid in the discernment of candidacy for HGNS, with a strong positive predictive value for PAP levels < 8 cm H2O. A larger prospective study is needed to confirm these findings.