Meta-analysis of Usefulness of Phrenic Nerve Stimulation in Central Sleep Apnea

Transvenous neurostimulation of the phrenic nerve (PNS) is a potentially improved and unique approach to the treatment of central sleep apnea (CSA). There have been multiple studies with limited individuals evaluating the efficacy of PNS. Our aim was to review and pool those studies to better understand whether phrenic nerve stimulation is efficacious in the treatment of CSA. The initial search on Pubmed retrieved a total of 97 articles and after screening all articles, only 5 could be included in our quantitative analysis. Pooling of data from 5 studies with a total of 204 patients demonstrated a reduction of mean apnea hypopnea index with PNS compared to controls by -26.7 events/hour with 95% confidence interval and P value of [CI (-31.99, -21.46), I² 85, p 0.00]. The mean difference in central apnea index was -22.47 [CI (-25.19, -19.76), I² 0, p 0.00]. The mean reduction in the oxygen desaturation index of 4% or more demonstrated a decrease in PNS group by -24.16 events/hour [(CI -26.20, -22.12), I² 0, p 0.00] compared with controls. PNS resulted in mean reduction in arousal index of -13.77 [CI (-16.15, -11.40), I² 0, p 0.00]. The mean change in percent of time spent in rapid eye movement sleep demonstrated a nonsignificant increase in PNS group by 1.01 % [CI (-5.67, 7.86), I²93, p 0.75]. In conclusion, PNS therapy for treating CSA demonstrated positive outcomes but larger randomized studies are needed to evaluate the safety and clinical outcomes.