title: Effectiveness of nocturnal home oxygen therapy to improve exercise capacity, cardiac function and cardiac sympathetic nerve activity in patients with chronic heart failure and central sleep apnea.
abstract: BACKGROUND
  Central sleep apnea, often found in patients with chronic heart failure (CHF), has a high risk of poor prognosis.
  
  
  RESULTS
  This study involved 20 patients with CHF (left ventricular ejection fraction (LVEF) <45%, M/F =19/1, age 65+/-10 years) and an apnea-hypopnea index (AHI) >5 times/h who were divided into 2 groups: 10 patients treated with nocturnal home oxygen therapy (HOT) and 10 patients without HOT (non-HOT). All patients had dilated cardiomyopathy and underwent overnight polysomnography, cardiopulmonary exercise testing, and nuclear cardiac examinations to evaluate AHI, exercise capacity according to the specific activity scale and oxygen uptake at anaerobic threshold and peak exercise (peak VO(2)). Cardiac function according to (99m)Tc-MIBI QGS, and the total defect score (TDS), H/M ratio and the washout rate (WR) on (123)I-metaiodobenzylguanidine (MIBG) imaging were calculated for all patients. As compared with the non-HOT group, the HOT group demonstrated a greater reduction in AHI (26.1+/-9.1 to 5.1+/-3.4), (123)I-MIBG TDS (31+/-8 to 25+/-9), and (123)I-MIBG WR (48+/-8% to 41+/-5%) and a greater increase in the specific activity scale (4.0+/-0.9 to 5.8+/-1.2 Mets), peak VO(2) (16.0+/-3.8 to 18.3+/-4.7 ml . min(-1) . kg(-1)), and LVEF (27+/-9% to 37+/-10%).
  
  
  CONCLUSIONS
  HOT improves exercise capacity, cardiac function, and cardiac sympathetic nerve activity in patients with CHF and central sleep apnea.
authors.affiliation: Gunma Prefectural Cardiovascular Center, Maebashi, Japan. toyama.t@cvc.pref.gunma.jp
authors.forename: Takuji
authors.initials: T
authors.lastname: Toyama
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Seki
authors.forename: Shu
authors.initials: S
authors.lastname: Kasama
authors.forename: Naoki
authors.initials: N
authors.lastname: Isobe
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sakurai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Adachi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hoshizaki
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshima
authors.forename: Koichi
authors.initials: K
authors.lastname: Taniguchi
mesh_terms: D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000379:methods*; D002908:Chronic Disease; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D020182:Sleep Apnea, Central / Q000209:etiology / Q000503:physiopathology*; D013318:Stroke Volume / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome