Abnormal ventilatory response to exercise in adults with congenital heart disease relates to cyanosis and predicts survival.
BACKGROUND
Limited data exist with which to stratify risk in adult congenital heart disease (ACHD). An increased ventilatory response to exercise, expressed as ventilation per unit of carbon dioxide production (V(E)/V(CO2) slope), is an established predictor of impaired survival in acquired heart disease. We sought to establish the distribution, relation to cyanosis, and prognostic value of the V(E)/V(CO2) slope across a wide spectrum of ACHD patients.


RESULTS
Five hundred sixty ACHD patients of varying diagnoses and 50 healthy controls underwent cardiopulmonary exercise testing at a single laboratory between 2001 and 2004. Patient age was 33.2 +/- 12.9 years (mean +/- SD). Peak oxygen consumption was 23.5 +/- 9.0 mL.kg(-1).min(-1).V(E)/V(CO2) slope for all patients was 36.3 +/-15.3. The slope was raised in all ACHD groups compared with controls and was 73% higher in cyanotic patients. Cyanosis, with or without pulmonary arterial hypertension, was the strongest predictor of abnormal V(E)/V(CO2) slope. The V(E)/V(CO2) slope was the most powerful univariate predictor of mortality in the noncyanotic group and the only independent predictor of mortality among exercise parameters on multivariate analysis. In cyanotic patients, no parameter was predictive of death.


CONCLUSIONS
Ventilatory response to exercise is abnormal across the spectrum of ACHD. Cyanosis is a powerful stimulus for such exaggerated ventilatory patterns irrespective of the presence of pulmonary arterial hypertension. Increased V(E)/V(CO2) slope is the strongest exercise predictor of death in noncyanotic ACHD patients.
Dimopoulos
Konstantinos
K
Adult Congenital Heart Programme, Department of Cardiology, Royal Brompton Hospital, Sydney St, London, SW3 6NP, United Kingdom.
Okonko
Darlington O
DO
Diller
Gerhard-Paul
GP
Broberg
Craig S
CS
Salukhe
Tushar V
TV
Babu-Narayan
Sonya V
SV
Li
Wei
W
Uebing
Anselm
A
Bayne
Stephanie
S
Wensel
Roland
R
Piepoli
Massimo F
MF
Poole-Wilson
Philip A
PA
Francis
Darrel P
DP
Gatzoulis
Michael A
MA
D000328:Adult; D002245:Carbon Dioxide / Q000032:analysis; D015331:Cohort Studies; D003490:Cyanosis; D005080:Exercise Test; D005260:Female; D006330:Heart Defects, Congenital / Q000145:classification / Q000401:mortality / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D006976:Hypertension, Pulmonary / Q000401:mortality / Q000503:physiopathology; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012123:Pulmonary Ventilation; D012189:Retrospective Studies; D012306:Risk; D016019:Survival Analysis
D002245:Carbon Dioxide