title: A non-invasively determined surrogate of cardiac power ('circulatory power') at peak exercise is a powerful prognostic factor in chronic heart failure.
abstract: OBJECTIVE
  This study was designed to assess the prognostic value of a new variable derived from a cardiopulmonary exercise test, the circulatory power, a surrogate of cardiac power, at peak exercise, in patients with chronic heart failure.
  
  
  BACKGROUND
  Peak exercise cardiac power and stroke work are invasive parameters with recently proven prognostic value. It is unclear whether these variables have better prognostic value than peak oxygen uptake (VO(2)).
  
  
  METHODS
  The study population comprised 175 patients with chronic heart failure (ejection fraction <45%) who underwent a cardiopulmonary exercise test. Circulatory power and circulatory stroke work were defined as the product of systolic arterial pressure and VO(2) and oxygen pulse, respectively. Prognostic value was assessed by survival curves (Kaplan-Meier method) and uni- and multivariate Cox analyses.
  
  
  RESULTS
  With a mean follow-up of 25+/-10 months, ejection fraction, heart rate, systolic arterial pressure, peak VO(2), VCO(2), the anaerobic threshold, minute ventilation, the ventilatory equivalents of oxygen and carbon dioxide, the half times of VO(2) and VCO(2) recoveries, and the circulatory stroke work and power predicted outcome. Multivariate analysis demonstrated that the peak circulatory power (chi-square=19.9, P<0.001) (but not peak circulatory stroke work) was the only variable predictive of prognosis.
  
  
  CONCLUSIONS
  The prognostic value of cardiopulmonary exercise tests in heart failure patients can be improved by assessing a new variable, the circulatory power - a surrogate of cardiac power - at peak exercise.
authors: Service de Cardiologie, Hôpital Beaujon, 92100 Clichy, 92110, France.
authors: A
authors: A
authors: Cohen-Solal
authors: J Y
authors: JY
authors: Tabet
authors: D
authors: D
authors: Logeart
authors: P
authors: P
authors: Bourgoin
authors: M
authors: M
authors: Tokmakova
authors: M
authors: M
authors: Dahan
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D002908:Chronic Disease; D003326:Coronary Circulation / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D011379:Prognosis; D013318:Stroke Volume / Q000502:physiology; D017741:Survivors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology
chemical_list: D015415:Biomarkers