0568 Phrenic Nerve Stimulation to Treat Idiopathic Central Sleep Apnea

Abstract

Introduction: Central sleep apnea (CSA) is common in patients with cardiovascular disease (CVD), but also occurs in patients without CVD. In a randomized double arm parallel design trial of 151 participants with moderate to severe CSA, 18/151 (twelve percent) had no known CVD defined as coronary disease, left ventricular dysfunction, heart failure, arrhythmias, or hypertension. Echocardiography showed normal LVEF and absence of significant diastolic dysfunction (posterior wall thickness ≤ 1.2 cm, E/a ratio between >0.8 and < 2.0). Methods: All polysomnograms were scored centrally. Sleep metrics and quality of life (QOL) were assessed by patient global assessment (PGA) and Epworth Sleepiness Scale (ESS). Change between 6 months and baseline was calculated for continuous endpoints. Safety was assessed by related serious adverse events (SAE) through 12 months. Results: There were six participants with idiopathic CSA in the treatment arm (TX) and 12 in the Control (Ctrl) arm. The mean age was 50 years, 83% were male and 50% had depression. The median apnea hypopnea index (AHI) was 37 events/hr, central apnea index (CAI) 25 events/hr, and Epworth Sleepiness Scale (ESS) score was 12. Following 6 months of PNS therapy, the mean AHI improved by 21±16 events/hr (TX) whereas Ctrl improved by 7±17 events/hr (p=0.049), with similar changes in the oxygen desaturation index. The median TX CAI improved from of 35 (Q1-Q3:20-53) to 9 (Q1-Q3:5-22) events/hr, whereas Ctrl changed from 24 (Q1-Q3:17-34) to 15 (Q1-Q3:4-31) events/hr (p=0.030). The arousal index decreased by a median 9 (Q1-Q3: -15 to 0) with TX and Ctrl decreased by 1 (Q1-Q3:-8 to 4) events/hour (p=0.241). Moderate or marked improvement in the patient global assessment was reported by 50% in TX versus 0% in Ctrl. The ESS improved by a median of 5.5 (Q1-Q3:-6.0 to -1.0) points in TX compared to 0.5 (Q1-Q3:-1 to 3.0) in Ctrl. Conclusion: PNS appears to improve sleep and quality of life safely and effectively in patients with idiopathic CSA.