Study objectivesTo assess the impact of transvenous phrenic nerve stimulation (TPNS) on non-rapid eye movement sleep microstructure quantified by cyclic alternating pattern (CAP) in individuals with central sleep apnea (CSA). MethodsWe analyzed baseline and 6-month follow-up overnight polysomnograms (PSG) in 134 CSA patients enrolled in the remedē System Pivotal Trial implanted with TPNS randomized (1:1) to neurostimulation (treatment group) or no stimulation (control group). Differences in CAP rate, A1 index, and A2+A3 index between study arms at follow-up were assessed using Analysis of Covariance adjusted for baseline values. ResultsOn follow-up PSG, the treatment group showed a decrease in the frequency of A2+A3 phases compared to controls (−5.86 ± 11.82 vs. 0.67 ± 15.25, p = 0.006), while the frequency of A1 phases increased more in the treatment group (2.57 ± 11.67 vs. −2.47 ± 10.60, p = 0.011). The change in CAP rate at follow-up was comparable between study arms. ConclusionsTPNS treatment for central sleep apnea may affect sleep microstructure. Brief phases of rapid cortical activity appear to be replaced by short phases of slower cortical activity, which may promote sleep continuity. Further investigations are warranted to elucidate the mechanisms underlying the effect of TPNS on CAP.
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