Transvenous phrenic nerve stimulation for the treatment of central sleep apnea reduces episodic hypoxemic burden

Study objectives: To determine the effect of transvenous phrenic nerve stimulation (TPNS) on the composition of the nocturnal hypoxemic burden in patients with CSA.Methods: We analysed oximetry data from baseline and follow-up overnight polysomnograms (PSG) in 134 CSA patients with implanted TPNS randomised (1:1) to neurostimulation (treatment group; TPNS on) or no stimu-lation (control group; TPNS off) from the remede over bar System Pivotal Trial. The hypoxemic burden was quantified using a battery of metrics, including the oxygen desaturation index (ODI), the relative sleep time spent below 90% SpO2 (T90) due to acute episodic desaturations (T90desat) and due to non-specific and non-cyclic drifts of SpO2 (T90non-specific). Mean change from baseline is provided.Results: TPNS titrated to reduce respiratory events significantly reduced the ODI in the treatment group by -15.85 h-1 +/- 1.99 compared to the control group, which increased 1.32 h-1 +/- 1.85 (p 0001) and shortened the relative T90 duration by-3.81 percentage points +/- 1.23 vs. 0.49 percentage points +/- 1.14 increase (p = 0.012). This shortening of T90 was primarily accomplished by reducing the brief cyclic desaturations (T90desaturation: -4.32 percentage points +/- 0.98 vs. 0.52 percentage points +/- 0.91, p = 0.0004) while notable non-specific drifts in SpO2 remained unchanged (T90non-specific: 0.18 percentage points +/- 0.62 vs.-0.13 percentage points +/- 0.57, p = 0.72).Conclusions: TPNS appears to significantly reduce the nocturnal hypoxemic burden due to sleep-disordered breathing, but a considerable nocturnal hypoxemic burden from other sources remains. Further investigations are warranted to identify the best strategy to reduce the nocturnal hypoxemic burden beyond preventing res-piratory events.

Automated summary

The study aimed to determine the effect of transvenous phrenic nerve stimulation (TPNS) on the composition of the nocturnal hypoxemic burden in CSA patients. The results showed that TPNS significantly reduced the oxygen desaturation index (ODI) and shortened the relative sleep time spent below 90% SpO2 (T90) in the treatment group. However, further investigations are needed to identify the best strategy to reduce the nocturnal hypoxemic burden.