The Caution for Auto-Titrating Continuous Positive Airway Pressure for Heart Failure Patients With Cheyne-Stokes Respiration and Central Sleep Apnea and Efficacy of Adaptive-Servo Ventilator

We appreciate the comments made by Drs Banno, Okamura and Kryger regarding our study.1 As they mentioned, the use of auto-titrating continuous positive airway pressure (APAP) for congestive heart failure (CHF) with Cheyne-Stokes respiration and central sleep apnea (CSRCSA) requires some caution. Therefore, in the present study, we carried out an overnight APAP trial during hospital admission under standard cardiac monitoring, as well as serial checking of mask fitting and leakage by a clinician, cardiology nurse or polysomnography technologist. However, because of the possibility of unexpected progressive increase in pressure occurring during an unattended trial, as noted by Drs Banno, Okamura and Kryger, we limited the auto-titrating pressure range to 4–12cmH2O, based on our previous experience.2 We should have described in detail our method of APAP titration, which would have addressed the precaution we took to prevent progressive increase in pressure. All the other studies described, such as the diagnostic study and several bi-level PAP titration studies, were attended. The adaptive servo ventilator (ASV), which has been recently introduced as an effective treatment of CSR-CSA in patients with CHF,3–5 reportedly reduced apnea-hypopnea index (AHI) on ASV more effectively than bi-level PAP. 3 In our pilot study of ASV for CSR-CSA in one CHF patient (65-year-old male), the AHI, was reduced from 50.1 events/h (including central apnea-hypopnea, 42.1 events/h) to 15.8 events/h by bi-level PAP and 1.4 events/h by ASV. Thus, we agree that the ASV would be the most effective option for the treatment of CSR-CSA in patients with CHF. However, ASV is not yet approved for clinical use in Japan and so we believe that our data on the efficacy of bi-level PAP are warranted and that it should be recommended as the best available treatment in Japan for CSR-CSA complicating CHF.