The effects of chronic implanted transvenous phrenic nerve stimulation in central sleep apnea: The remede(R) System pilot study

Abstract

Introduction: Central sleep apnea (CSA) is associated with increased morbidity and mortality and frequently occurs in heart failure patients. Current treatment options for CSA have been limited and focus on mask based therapies and therefore are highly dependent on tolerability and adherence. A novel therapy utilizing phrenic nerve stimulation was developed using the remede¯ System, a transvenous, fully implantable system which is intended to restore a normal breathing pattern throughout the night. This is the first study to evaluate the effects of chronic respiratory rhythm management utilizing the remede¯® System through 3 and 6 months. Methods: Subjects received a remede¯® System consisting of a respistim™ transvenous stimulation lead (in either the left pericardiophrenic vein or the right brachiocephalic vein) and a remedc¸® pulse generator (IPG) which was placed in the pectoral area and secured in a normal fashion. Forty-seven subjects with predominantly CSA (mean age 66±10 years, mean baseline AHI 50±15 n/hour) were evaluated at baseline and after 3 and 6 months of therapy. Fifty-three percent of subjects had a concomitant cardiac device and 79% of subjects had chronic heart failure. Standard polysomnographic criteria were used for classification of disordered events and arousals. Results: Three month data demonstrate significant improvements in AHI, central apnea index, oxygen desaturation index of 4%, arousal index, REM sleep and sleep efficiency (table below). There was no deterioration in obstructive sleep apnea index. (table Presented) Conclusions: Treatment of CSA with the remede¯® System significantly improves both respiratory and sleep parameters including AHI, central apneas, arousals, and REM sleep. These favorable changes in pathophysiological consequences of sleep apnea could lead to improvements in clinical status and outcomes of patients with heart failure. Additional follow-up data including cardiovascular and symptom changes at 6 months will be available in August 2013.