Article

Increased ventilatory (.VE) response to carbon dioxide output (.VCO2)
is a key finding of incremental cardiopulmonary exercise testing in both heart
failure and pulmonary arterial hypertension (PAH). As with heart failure,
measures of excessive exercise ventilation considering high-to-peak exercise
.VE-VCO2 might have higher prognostic relevance than those restrained to
sub-maximal exercise in PAH. DESIGN: Cross-sectional and observational study on a
tertiary center. METHODS: Eighty-four patients (36 idiopathic and 48 with
associated conditions) were followed up for up to five years. Excessive exercise
ventilation was calculated as a slope (Delta .VE/Delta .VCO2 to the respiratory
compensation point (RCP) and to exercise cessation (PEAK)) and as a ratio
(.VE-VCO2 at the anaerobic threshold (AT) and at PEAK). RESULTS: Thirteen
patients died and three had atrial septostomy. Multivariable regression analyses
revealed that Delta .VE/Delta .VCO2(PEAK) <55 and .VE/.VCO2(PEAK) <57 were better
related to prognosis than Delta .VE/Delta .VCO2(RCP) and .VE/.VCO2(AT) (p <
0.01). Delta oxygen uptake (.VO2)/Delta work rate >5.5 ml/min per W was the only
other independent prognostic index. According to a Kaplan-Meier survival
analysis, 96.9% (90.8% to 100%) of patients showing Delta .VE/Delta .VCO2(PEAK)
<55 and Delta .VO2/Delta work rate >5.5 ml/min per W were free from a PAH-related
event. In contrast, 74.7% (70.1% to 78.2%) with both parameters outside these
ranges had a negative outcome. CONCLUSION: Measurements of excessive exercise
ventilation which consider all data points maximize the usefulness of incremental
cardiopulmonary exercise testing in the prognosis evaluation of PAH.
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Langue : ANGLAIS