Phrenic nerve stimulation for central sleep apnea: a single institution experience.

Purpose: Phrenic nerve stimulation (PNS) was approved by the Food and Drug Administration (FDA) to treat moderate to severe central sleep apnea. We report here, results of a retrospective study regarding our institutional outcomes at one year. In this study we evaluated the change in the apnea hypopnea index, epworth sleepiness score, and functional outcomes of sleep score at one year post implant.

Methods: This is a retrospective analysis of patients ≥ 18 years of age who had PNS implanted for moderate to severe CSA at the Ohio State University Wexner Medical Center apnea between Feb 1, 2018 to July 1, 2021. Sleep disordered breathing parameters and objective sleepiness as measured by the Epworth Sleepiness Scale (ESS) scores, and Functional Outcomes of Sleep Questionnaire (FOSQ) scores were assessed at baseline and one-year post-implant.

Results: Twenty-two patients were implanted with PNS at OSU between February 1, 2018 and May, 31, 2022. The AHI showed a statistically significant decrease from a median of 40 events/hour at baseline to 18 at follow-up (p-value = 0.003). The CAI decreased from 16 events/hour to 2 events/hour (p-value of 0.001). The obstructive apnea index, mixed apnea index, and hypopnea index did not significantly change. The ESS scores had a statistically significant improvement from a median score of 12 to 9 (p-value = 0.028). While the FOSQ showed a trend to improvement from 15.0 to 17.8, it was not statistically significant (p-value of 0.086).

Conclusion: Our study found that PNS therapy for moderate to severe CSA improves overall AHI and CAI. Objective sleepiness as measured by the ESS also improved at one-year post implant.