title: A pacemaker transthoracic impedance sensor with an advanced algorithm to identify severe sleep apnea: the DREAM European study.
abstract: BACKGROUND
  Sleep apnea (SA) is associated with cardiovascular diseases and is highly prevalent in patients with pacemakers (PMs).
  
  
  OBJECTIVE
  To validate a transthoracic impedance sensor with an advanced algorithm (sleep apnea monitoring) for identifying severe SA.
  
  
  METHODS
  Patients with indications for PM (VVI/DDD) were enrolled regardless of symptoms suggesting SA. Severe SA diagnosis was acknowledged when the full polysomnography gave an apnea-hypopnea index (PSG-AHI) of ≥30 events/h. The PSG-AHI was compared with the respiratory disturbance index evaluated by the SAM algorithm (SAM-RDI) compiled from the device during the same diagnosis night, and the performance of the device and the SAM algorithm was calculated to identify patients with severe SA. The agreement between methods was assessed by using Bland and Altman statistics.
  
  
  RESULTS
  Forty patients (mean age 73.8 ± 19.1 years; 67.5% men; body mass index 27.7 ± 4.4 kg/m(2)) were included. Severe SA was diagnosed by PSG in 56% of the patients. We did not retrieve SAM-RDI data in 14% of the patients. An optimal cutoff value for the SAM-RDI at 20 events/h was obtained by a receiver operator characteristic curve analysis, which yielded a sensitivity of 88.9% (95% confidence interval [CI] 65.3%-98.6%), a positive predictive value of 88.9% (95% CI 65.3%-98.6%), and a specificity of 84.6% (95% CI 54.6%-98.1%) (n = 31). The Bland-Altman limits of agreement for PSG-AHI (in events per hour) were [-14.1 to 32.4].
  
  
  CONCLUSIONS
  The results suggest that an advanced algorithm using PM transthoracic impedance could be used to identify SA in patients with PMs outside the clinic or at home.
authors.affiliation: Arrhythmia Unit, Cardiology Department, University Hospital, Grenoble, France. Electronic address: PDefaye@chu-grenoble.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Defaye
authors.affiliation: Sleep Unit, Pneumology Service, Virgen de Valme University Hospital, Sevilla, Spain.
authors.forename: Ines
authors.initials: I
authors.lastname: de la Cruz
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital del Mar, Barcelona, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Martí-Almor
authors.affiliation: Electrophysiology and Arrhythmia Unit, Department of Cardiology, Germans Trias I Pujol Hospital, Badalona, Spain.
authors.forename: Roger
authors.initials: R
authors.lastname: Villuendas
authors.affiliation: La Rochelle Hospital, La Rochelle, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Bru
authors.affiliation: SORIN CRM SAS, Clamart, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Sénéchal
authors.affiliation: Central Core Lab, Sleep Laboratory, University Hospital, Grenoble, France; University of Grenoble Alpes, HP2, Inserm, Grenoble, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Tamisier
authors.affiliation: Central Core Lab, Sleep Laboratory, University Hospital, Grenoble, France; University of Grenoble Alpes, HP2, Inserm, Grenoble, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pépin
mesh_terms: D000368:Aged; D000465:Algorithms; D001919:Bradycardia / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D002307:Cardiography, Impedance; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D010138:Pacemaker, Artificial; D017286:Polysomnography; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D013030:Spain / Q000453:epidemiology
keywords: Bradycardia; Minute ventilation; Pacemaker; Sleep apnea; Sleep apnea diagnosis