title: Prognostic impact of ventilatory efficiency in heart disease patients with preserved exercise tolerance.
abstract: BACKGROUND
  The minute ventilation/carbon-dioxide output (VE/VCO2) slope as a marker of cardiac events has been established in patients with severe heart failure, but it is not known whether it is useful for other heart diseases.
  
  
  RESULTS
  The present study investigated 215 patients with various heart diseases (age 59+/-11 years; ischemic heart disease, n=89; dilated cardiomyopathy, n=38; valvular disease, n=37; hypertensive heart disease, n=33; others, n=18) who underwent cardiopulmonary exercise testing to determine the VE/VCO(2) slope. Patients were divided into 2 groups according to the VE/VCO2 slope and were followed-up for 3 years. Forty-eight cardiac events (6 deaths, 42 re-hospitalizations) occurred during the observation period. Patients with a VE/VCO2 slope >34 had a significantly higher 3-year cardiac event rate (32.1%) than patients with VE/VCO2 slope <34 (18.9%, p<0.05). When patients were selected with relatively preserved peak oxygen uptake values (>16 ml . kg (-1) . min(-1)), patients with VE/VCO2 slope >34 still demonstrated a significantly higher cardiac event rate than other patients (35.0% vs 13.3%, p<0.01).
  
  
  CONCLUSIONS
  The VE/VCO2 slope may be a prognostic indicator of cardiac events in a heterogeneous group of patients with heart disease, independent of exercise tolerance.
authors.affiliation: Department of Medicine and Biological Science, Graduate School of Medical Sciences, Gunma University, Japan. turugaya@wb3.so-net.ne.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Tsurugaya
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Adachi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohshima
authors.forename: Koichi
authors.initials: K
authors.lastname: Taniguchi
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis*; D018572:Disease-Free Survival; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis*; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011379:Prognosis; D011659:Pulmonary Gas Exchange