title: Safety and feasibility of chronic transvenous phrenic nerve stimulation for treatment of central sleep apnea in heart failure patients.
abstract: BACKGROUND
  Central sleep apnea (CSA) is common in patients with heart failure (HF) and is associated with poor quality of life and prognosis. Early acute studies using transvenous phrenic nerve stimulation (PNS) to treat CSA in HF have shown a significantly reduction of CSA and improvement of key polysomnographic parameters. In this study, we evaluated the safety of and efficiency chronic transvenous PNS with an implanted neurostimulator in HF patients with CSA.
  
  
  METHODS
  This study was a prospective, nonrandomized evaluation of unilateral transvenous PNS in eight HF patients with CSA. The stimulation lead, which connected to a proprietary neurostimulator, was positioned in either the left pericardiophrenic or right brachiocephalic vein. Monitoring during implantation and 6-monthly follow-ups were performed.
  
  
  RESULTS
  Six of the implanted eight patients completed the study (one was lost to follow-up; one died from pneumonia). Neither side effects nor adverse events related to stimulation occurred. During the 6-monthly follow-ups, one patient had a lead dislodgement in the first month and the lead was subsequently repositioned. No additional lead dislodgements occurred. There were no significant changes in sleep habits, appetite, bleeding or infections. Compared with the parameters before stimulator implantation, there were significant improvement in apnea-hypopnea index, central apnea index, left ventricular ejection fraction and 6-min walk distance (all P < 0.01).
  
  
  CONCLUSIONS
  Use of chronic transvenous PNS appears to be safe and feasible in HF patients with CSA. Large multicenter studies are needed to confirm safety and efficacy in this population.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Xilong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.affiliation: Department of Cardiothoracic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Buqing
authors.initials: B
authors.lastname: Ni
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Yang
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Cardiothoracic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Shi-Jiang
authors.initials: SJ
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010791:Phrenic Nerve / Q000502:physiology*; D017286:Polysomnography; D011446:Prospective Studies; D011788:Quality of Life; D020182:Sleep Apnea, Central / Q000628:therapy*; D004561:Transcutaneous Electric Nerve Stimulation / Q000009:adverse effects* / Q000295:instrumentation; D016896:Treatment Outcome
keywords: Cheyne-Stokes respiration; central sleep apnea; heart failure; phrenic nerve stimulation