title: A new predictive equation for oxygen consumption in children and adults with congenital and acquired heart disease.
abstract: OBJECTIVE
  To develop a new predictive equation for oxygen consumption (VO2) in children and adults with congenital and acquired heart disease.
  
  
  METHODS
  We retrospectively reviewed data from 502 consecutive patients (age 0-59 years) undergoing cardiac catheterisation with measured VO2 (M-VO2) and compared M-VO2 with VO2 from the LaFarge equations (LF-VO2) in patients <3 years (Group 1) and ≥3 years (Group 2). Factors associated with inaccurate LF-VO2 were used to develop a new predictive equation, which was prospectively validated in 100 consecutive patients (age 0-59 years).
  
  
  RESULTS
  LF-VO2 was inaccurate in 42% of Group 1 (n=201) and 13% of Group 2 (n=301). Multivariable predictors of inaccurate LF-VO2 included age (OR 0.41, p=0.01) and single ventricle anatomy (OR 2.98, p=0.03) in Group 1 and anaemia (OR 0.84, p<0.001) in Group 2. Critical illness was borderline significant in both groups. The new predictive equation for VO2:[Formula: see text] Intraclass correlation between M-VO2 and the new predictive equation was good (r=0.53), whereas LF-VO2 was not (r=0.17). Bland-Altman analysis comparing M-VO2 with the new equation and with LF-VO2 demonstrated superiority of the new equation (mean bias 2.5 mL/min/m(2) vs -5.0 mL/min/m(2); limits of agreement -51.6, 56.5 vs -82.1, 72).
  
  
  CONCLUSIONS
  VO2 derived from the LaFarge equations is frequently inaccurate, particularly in younger patients, and will lead to erroneous haemodynamic calculations. We developed and prospectively validated a new VO2 predictive equation for use in patients of all ages with congenital and acquired heart disease.
authors.affiliation: The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Seckeler
authors.affiliation: The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Russel
authors.initials: R
authors.lastname: Hirsch
authors.affiliation: The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Beekman
authors.affiliation: The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Bryan H
authors.initials: BH
authors.lastname: Goldstein
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005544:Forecasting; D006331:Heart Diseases / Q000151:congenital* / Q000378:metabolism*; D006801:Humans; D007223:Infant; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D010101:Oxygen Consumption; D012189:Retrospective Studies; D055815:Young Adult