title: Exercise intolerance in adult congenital heart disease: comparative severity, correlates, and prognostic implication.
abstract: BACKGROUND
  Although some patients with adult congenital heart disease (ACHD) report limitations in exercise capacity, we hypothesized that depressed exercise capacity may be more widespread than superficially evident during clinical consultation and could be a means of assessing risk.
  
  
  RESULTS
  Cardiopulmonary exercise testing was performed in 335 consecutive ACHD patients (age, 33+/-13 years), 40 non-congenital heart failure patients (age, 58+/-15 years), and 11 young (age, 29+/-5 years) and 12 older (age, 59+/-9 years) healthy subjects. Peak oxygen consumption (peak VO2) was reduced in ACHD patients compared with healthy subjects of similar age (21.7+/-8.5 versus 45.1+/-8.6; P<0.001). No significant difference in peak VO2 was found between ACHD and heart failure patients of corresponding NYHA class (P=NS for each NYHA class). Within ACHD subgroups, peak VO2 gradually declined from aortic coarctation (28.7+/-10.4) to Eisenmenger (11.5+/-3.6) patients (P<0.001). Multivariable correlates of peak VO2 were peak heart rate (r=0.33), forced expiratory volume (r=0.33), pulmonary hypertension (r=-0.26), gender (r=-0.23), and body mass index (r=-0.19). After a median follow-up of 10 months, 62 patients (18.5%) were hospitalized or had died. On multivariable Cox analysis, peak VO2 predicted hospitalization or death (hazard ratio, 0.937; P=0.01) and was related to the frequency and duration of hospitalization (P=0.01 for each).
  
  
  CONCLUSIONS
  Exercise capacity is depressed in ACHD patients (even in allegedly asymptomatic patients) on a par with chronic heart failure subjects. Lack of heart rate response to exercise, pulmonary arterial hypertension, and impaired pulmonary function are important correlates of exercise capacity, as is underlying cardiac anatomy. Poor exercise capacity identifies ACHD patients at risk for hospitalization or death.
authors.affiliation: Adult Congenital Heart Program, Department of Cardiology, Royal Brompton Hospital, London, UK.
authors.forename: Gerhard-Paul
authors.initials: GP
authors.lastname: Diller
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Dimopoulos
authors.forename: Darlington
authors.initials: D
authors.lastname: Okonko
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Sonya V
authors.initials: SV
authors.lastname: Babu-Narayan
authors.forename: Craig S
authors.initials: CS
authors.lastname: Broberg
authors.forename: Bengt
authors.initials: B
authors.lastname: Johansson
authors.forename: Beatriz
authors.initials: B
authors.lastname: Bouzas
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mullen
authors.forename: Philip A
authors.initials: PA
authors.lastname: Poole-Wilson
authors.forename: Darrel P
authors.initials: DP
authors.lastname: Francis
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gatzoulis
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005080:Exercise Test / Q000009:adverse effects*; D017079:Exercise Tolerance / Q000502:physiology*; D006330:Heart Defects, Congenital / Q000503:physiopathology*; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D010101:Oxygen Consumption; D011379:Prognosis; D012016:Reference Values; D012189:Retrospective Studies