title: High prevalence and persistence of sleep apnoea in patients referred for acute left ventricular failure and medically treated over 2 months.
abstract: OBJECTIVE
  Cardiac failure patients were studied systematically using polysomnography 1 month after recovering from acute pulmonary oedema, and again after 2 months of optimal medical treatment for cardiac failure.
  
  
  RESULTS
  This prospective study of consecutive patients was conducted in a cardiac care unit of a university hospital. V o(2)measurements and left ventricular ejection fraction were recorded. Thirty-four patients, initially recruited with pulmonary oedema, improved after 1 month of medical treatment to NYHA II or III. They were aged less than 75 years and had a left ventricular ejection fraction less than 45% at the time of inclusion. Age was 62 (9) years, body mass index= 27 (5) kg x m(-2)and an ejection fraction= 30 (10)%. Eighteen of the 34 patients (53%) had coronary artery disease. Twenty-eight of the 34 had sleep apnoea syndrome with an apnoea+hypopnoea index >15 x h(-1)of sleep. Thus, the prevalence of sleep apnoea in this population was 82%. Twenty-one of 28 (75%) patients had central sleep apnoea and seven of 28 (25%) had obstructive sleep apnoea. Patients with central sleep apnoea had a lower Pa co(2)than those with obstructive sleep apnoea (33 (5) vs 37 (5) mmHg, P<0.005). Significant correlations were found between apnoea+hypopnoea index and peak exercise oxygen consumption (r= -0.73, P<0.01), and apnoea+hypopnoea index and Pa co(2)(r= -0.42, P = 0.03). When only central sleep apnoea patients were considered, a correlation between apnoea+hypopnoea index and left ventricular ejection fraction was also demonstrated (r= -0.46, P<0.04). After 2 months of optimal medical treatment only two patients (both with central sleep apnoea) showed improvement (apnoea+hypopnoea index <15 x h(-1)).
  
  
  CONCLUSIONS
  We have demonstrated a high prevalence of sleep apnoea, which persisted after 2 months of medical treatment, in patients referred for acute left ventricular failure. Central sleep apnoea can be considered a marker of the severity of congestive heart failure.
authors.affiliation: Department of Cardiology, University Hospital, Grenoble, France.
authors.forename: F
authors.initials: F
authors.lastname: Tremel
authors.forename: J L
authors.initials: JL
authors.lastname: Pépin
authors.forename: D
authors.initials: D
authors.lastname: Veale
authors.forename: B
authors.initials: B
authors.lastname: Wuyam
authors.forename: J P
authors.initials: JP
authors.lastname: Siché
authors.forename: J M
authors.initials: JM
authors.lastname: Mallion
authors.forename: P
authors.initials: P
authors.lastname: Lévy
mesh_terms: D000368:Aged; D002639:Cheyne-Stokes Respiration / Q000209:etiology; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013147:Spirometry; D018709:Statistics, Nonparametric; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000628:therapy