Phrenic nerve stimulation in patients with central sleep apnoea. A single-centre experience from the Pilot and Pivotal trials.

BACKGROUND Patients with central sleep apnea (CSA) have recently been shown to have improved sleep metrics and quality of life (QoL) with phrenic nerve stimulation (PNS). AIMS The aim of this study was to report the results of a partnership between cardiology, sleep medicine, and electrophysiology in a single clinical center as well as the enrollment, implantation, and follow-up experience demonstrating both the safety and efficacy of PNS. METHODS This analysis included data from the pilot and pivotal trials investigating the effect of PNS using an implantable transvenous system in patients with CSA. We present our experience and data on the enrollment processes, implantation feasibility and safety, sleep indices, and QoL at 6 and 12 months of follow-up. RESULTS Between June 2010 and May 2015, cardiology patients were prescreened and 588 of them were sent for in-home sleep test. Ninety-six patients were referred for polysomnographic studies, and 33 were enrolled and had an implant attempt, with 31 successfully receiving an implant. The apnea-hypopnea index was reduced in the pilot trial (mean [SD] of 48.7 [15.5] events/h to 22.5 [13.2] events/h; P < 0.001) and in the pivotal trial (mean [SD] of 48.3 [18.8] events/h to 26.0 [21.9] events/h; P < 0.001). Improvement in QoL was also observed. CONCLUSIONS We showed that PNS improved sleep metrics and QoL in patients with CSA, which is a result of multiple factors, including a comprehensive coordination between cardiology, sleep medicine, and electrophysiology. This ensures appropriate patient identification leading to safe implantation and full patient compliance during follow-up visits.