Long-Term Experience with First-Generation Implantable Neurostimulation Device in Central Sleep Apnea Treatment

Sleep-disordered breathing (SDB) and Cheyne-Stokes respiration (CSR) are associated with shorter survival in patients with heart failure. A novel treatment method for this patient group is unilateral phrenic nerve stimulation by the remedē® system (Respicardia Inc., Minnetonka, MN, USA), a transvenously implantable neurostimulation device, which has recently been studied in a large randomized, controlled trial. Previous literature has shown efficacy and safety of the treatment with this first-generation device, but hardly any data are available on long-term clinical parameters, the remedē® device's battery lifetime, device exchangeability, lead position stability, surgical accessibility, and manageability.

We performed remedē® device replacements in consecutive patients for battery depletion, and documented clinical parameters, longevity, operation procedure, complications, and difficulties.

All patients were on neurostimulation treatment by phrenic nerve neurostimulation when device replacement became necessary. Apnea-hypopnea index (from 45 ± 4/h to 9 ± 4/h), oxygen-desaturation index (from 35 ± 7/h to 7 ± 6/h), and time spent with oxygen saturation of <90% (T < 90% from 5 ± 7% to 0 ± 0%) were improved and improvements remained constant throughout the 4-year follow-up. Mean battery life was 4.2 ± 0.2 years and mean replacement procedure time was 25 ± 5.1 minutes. Apart from conventional X-ray documentation of stable lead positions in a long-term setting, no radiation or contrast dye usage was needed and no major complications occurred. In addition, clinical exercise capacity and sleepiness symptoms improved.

Novel remedē® device shows sustained therapy efficacy and safety in terms of stable lead positions over 4 years. Long-term phrenic nerve neurostimulation therapy for central SDB/CSR appears feasible in a clinical routine setting.