Phrenic Nerve Stimulation Improves Physical Performance and Hypoxemia in Heart Failure Patients with Central Sleep Apnea

Background: Central sleep apnea (CSA) is a common comorbidity in patients with heart failure (HF) and has been linked to increased morbidity and mortality risk. In addition, CSA is associated with impaired quality of life, reduced physical performance capacity, and hypoxemia. Phrenic nerve stimulation (PNS) is a novel approach to the treatment of CSA and has been shown to be safe and effective in this indication. However, there are currently no data on the effects of PNS on physical performance and hypoxia in CSA HF patients, both of which have been shown to be linked to mortality in HF. Methods: This prospective study enrolled patients with HF and CSA diagnosed using polysomnography. All were implanted with a PNS system (remedē(®) system, Respicardia Inc., Minnetonka, MN, USA) for the treatment of CSA. Examinations included polysomnography (to determine hypoxemic burden), echocardiography and a standardized 6-min walk test prior to device implantation (baseline) and after 6 months of follow-up. Results: A total of 24 patients were enrolled (mean age 67.1 ± 11.2 years, 88% male). The 6-min walk distance was 369.5 ± 163.5 m at baseline and significantly improved during follow-up (to 410 ± 169.7 m; p = 0.035). Hypoxemic burden, determined based on time with oxygen saturation < 90% improved from 81 ± 55.8 min at baseline to 27.9 ± 42.8 min during PNS therapy (p < 0.01). Conclusion: In addition to safely and effectively treating CSA, PNS is also associated with improved physical performance capacity and reduced hypoxemic burden in patients with HF.