0618 Phrenic Nerve Stimulation for Central Sleep Apnea: A Single Institution Experience

Abstract Introduction Central sleep apnea (CSA) is a form of sleep disordered breathing where there is a lack of drive to breathe during sleep. CSA has been associated with symptoms of poor sleep and daytime sleepiness. Moderate to severe CSA (central apnea index (CAI) >=15 central apneas/hour of sleep) has been associated with increased risk of heart failure, depressed heart rate variability, and higher incidence of nonsustained ventricular tachycardia [2-4]. Treatment of CSA has mainly centered around positive airway pressure (PAP) therapy. Phrenic nerve stimulation (PNS) was approved in 2017 for moderate to severe CSA. PNS is an implantable device that transvenously stimulates the phrenic nerve in order to stimulate the hemidiaphragm. PNS therapy was approved after the remedē System Pivotal trial that showed a ≥ 50% reduction in AHI and improvement in patient global assessment scale in patients with moderate to severe CSA [12]. Methods This is a retrospective analysis of patients ≥ 18 years of age who had PNS implanted for moderate to severe CSA at the OSUWMC. Patient data was gathered prior to implant and at a follow-up visit one year after implant to assess efficacy and safety. Data collection including sleep study results, 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 improved from a median of 40 events/hour at baseline to 18 at follow-up (p-value =0.003). This improvement in AHI was primarily from a reduction in the CAI, which was reduced 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 improved from a median score of 12 to 9 (p-value =0.028). The FOSQ, improved from 15.0 to 17.8 but was not significant (p-value of 0.086). Conclusion PNS therapy shows improvement in overall AHI, primarily from the reduction of central apnea events. There was also significant improvement in ESS and a trend to improvement in FOSQ at one-year follow-up. Minimal safety concerns were reported. Support (if any)