Costanzo, Maria Rosa

Abstract Introduction Adherence with mask-based therapies remains a significant challenge for optimal treatment of patients with sleep disordered breathing. Transvenous phrenic nerve stimulation (TPNS) to treat central sleep apnea offers a novel, automated approach to enhance nightly adherence by initiating therapy based on patient-specific programmed conditions such as sleep schedule, activity, and body position. Therapy automatically pauses when the patient sits up or changes position, facilitating re-initiation of sleep. This research aimed to determine the degree of adherence achieved with TPNS’s automated activation approach. Methods Device data from 128 remedē® System Pivotal Trial participants were analyzed to calculate hours of therapy activation. Daily use from device data within the 14 days prior to scheduled visits were used to calculate median daily hours of therapy per patient, and subsequently the overall median daily use for all patients. Therapy duration was defined as the sum of time of delivered therapy when all conditions to activate therapy were met between the first time therapy came on to the last time off during the night, excluding time when activity or body position did not meet the programmed criteria for therapy activation. Results The median [Q1-Q3] nightly therapy duration at 6, 12, 18, and 24 months was 5.9 [4.9-6.6], 5.7 [5.0-6.8], 6.0 [5.3-6.8], and 5.9 [4.9-6.5] hours, respectively. Using a definition for adequate therapy as the percentage of patients with usage ≥4 hours/night for at least 70% of nights, 86%, 82%, 83%, and 90% of patients met the criteria at these visits. Only two patients (< 2%) who had therapy activated discontinued treatment prior to 6 months due to stimulation intolerance. Patients with median delivered therapy ≥4 hours/night reported more quality of life improvement than patients with < 4 hours of therapy. Conclusion The automatic activation of TPNS therapy resulted in a higher duration of nightly usage and higher rate of adequate delivered therapy than generally are reported for mask-based therapies. This high usage may yield a greater overall reduction in central sleep apnea burden over the whole night compared to therapies that require the patient to initiate the therapy. Support (if any) ZOLL Respicardia, Inc.

Abstract Central sleep apnea, a rare polysomnographic finding in the general population, is prevalent in certain cardiovascular conditions including systolic and diastolic left ventricular dysfunction, atrial fibrillation, coronary artery disease, carotid artery stenosis, stroke, and use of certain cardiac-related medications. Polysomnographic findings of central sleep apnea with adverse cardiovascular impacts include nocturnal hypoxemia and arousals, which can lead to increased sympathetic activity both at night and in the daytime. Among cardiovascular diseases, central sleep apnea is most prevalent in patients with left ventricular systolic dysfunction; a large study of more than 900 treated patients has shown a dose-dependent relationship between nocturnal desaturation and mortality. Multiple small randomized controlled trials have shown mitigation of sympathetic activity when central sleep apnea is treated with nocturnal oxygen, continuous positive airway pressure, and adaptive servoventilation. However, two early randomized controlled trials with positive airway pressure devices have shown either a neutral effect on survival or excess premature mortality in the active treatment arm, compared to untreated central sleep apnea. In contrast, the results of the most recent trial using an advanced adaptive servoventilation device showed improved quality of life and no signal for mortality suggesting that treatment of central sleep apnea was at least safe. In addition to positive airway pressure devices, multiple medications have been shown to improve central sleep apnea, but no long-term trials of pharmacologic therapy have been published. Currently, phrenic nerve stimulation is approved for the treatment of central sleep apnea, and the results of a randomized controlled trial showed significant improvement in sleep metrics and quality of life.