title: Ischemic etiology of heart failure identifies patients with more severely impaired exercise capacity.
abstract: BACKGROUND
  Peak oxygen uptake (peak VO2) and the regression slope of ventilation against CO2 production during exercise (VE/VCO2 slope) are powerful prognostic indicators in patients with chronic heart failure (CHF). Our purpose was to evaluate the influence of CHF etiology on peak VO2 and VE/VCO2 slope, independently of demographic, clinical, Doppler-echocardiographic and neurohormonal factors.
  
  
  METHODS
  Data were collected from 239 CHF patients referred for a cardiopulmonary exercise test as part of their clinical evaluation. Patients were stratified according to their CHF etiology (ischemic versus non-ischemic).
  
  
  RESULTS
  The etiology of heart failure was ischemic in 143 patients (60%) and non-ischemic in 96 (40%). Patients with ischemic etiology, compared with those with non-ischemic etiology, showed a lower peak VO2 (15.4+/-4.2 versus 17.8+/-4.8 ml/kg/min, p<0.0001) and a steeper VE/VCO2 slope (38.1+/-6.8 versus 34+/-5.3, p<0.0001). In the univariate model, age (r=-0.36, p<0.0001), female sex (r=-0.21, p=0.001), ischemic CHF etiology (r=-0.26, p<0.0001) and NYHA class (r=-0.52, p<0.0001) correlated with peak VO2. At multivariate analysis, ischemic CHF etiology (beta=-0.23, p=0.001) was a predictor of peak VO2 (R(2)=0.49) independently of age (beta=-0.23, p=0.001), female sex (beta=-0.25, p=0.0006) and NYHA class (beta=-0.31, p<0.0001). Similarly, ischemic etiology (beta=0.29, p=0.001) predicted the VE/VCO2 slope (R(2)=0.38) independently of E/A ratio (beta=0.27, p=0.01) and resting heart rate (beta=0.22, p=0.01).
  
  
  CONCLUSIONS
  Etiology of heart failure may influence the functional capacity and the ventilatory response to exercise.
authors.affiliation: Divisione Clinicizzata di Cardiologia, Ospedale Civile Maggiore Piazzale Stefani 1, I-37126 Verona, Italy. stefania.defeo@tiscali.it
authors.forename: Stefania
authors.initials: S
authors.lastname: De Feo
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Franceschini
authors.forename: Giovanna
authors.initials: G
authors.lastname: Brighetti
authors.forename: Mariantonietta
authors.initials: M
authors.lastname: Cicoira
authors.forename: Luisa
authors.initials: L
authors.lastname: Zanolla
authors.forename: Andrea
authors.initials: A
authors.lastname: Rossi
authors.forename: Giorgio
authors.initials: G
authors.lastname: Golia
authors.forename: Piero
authors.initials: P
authors.lastname: Zardini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000450:Aldosterone / Q000097:blood; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D004452:Echocardiography; D004837:Epinephrine / Q000097:blood; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D018377:Neurotransmitter Agents / Q000097:blood; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology
chemical_list: D018377:Neurotransmitter Agents; D000450:Aldosterone; D009638:Norepinephrine; D004837:Epinephrine