Pacing therapies for sleep apnea and cardiovascular outcomes: A systematic review.

Purpose: Phrenic and hypoglossal nerve pacing therapies have shown benefit in sleep apnea. We sought to analyze the role of pacing therapies in sleep apnea and their impact on heart failure.
Methods: A comprehensive literature search in PubMed and Google Scholar from inception to August 5, 2019, was performed. A meta-analysis was performed using fixed effects model to calculate mean difference (MD) with 95% confidence interval (CI).
Results: Six studies were eligible and included 626 patients, of whom 334 were in the control arm and 393 were in the experimental arm. Phrenic nerve pacing (MD - 23.20 events/h, 95% CI - 27.96 to - 18.44, p < 0.00001) and hypoglossal nerve pacing (MD - 20.24 events/h, 95% CI - 23.22 to - 17.27, p < 0.00001) were associated with improvements in apnea-hypopnea index (AHI). Phrenic nerve pacing was associated with a trend towards improvements in left ventricular ejection fraction (MD 3.95%, 95% CI - 0.04 to 7.94, p = 0.05). Hypoglossal and phrenic nerve pacing were associated with improvements in the quality of life as assessed by improvements in Epworth sleepiness scale (MD 3.71 points, 95% CI 2.89 to 4.54, p < 0.00001).
Conclusions: Our analysis suggests that phrenic and hypoglossal nerve pacing improves AHI and quality of life with a trend towards improvement in left ventricular ejection fraction, especially in central sleep apnea. Complications were high but future refinement in technology will likely improve clinical outcomes and minimize complications.