Optimizing the evaluation of excess exercise ventilation for prognosis assessment in pulmonary arterial hypertension

Background Increased ventilatory ( V · E) response to carbon dioxide output ( V · CO2) 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 V · E– V · CO2 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 (Δ V · E/Δ V · CO2 to the respiratory compensation point (RCP) and to exercise cessation (PEAK)) and as a ratio ( V · E/ V · CO2 at the anaerobic threshold (AT) and at PEAK). Results Thirteen patients died and three had atrial septostomy. Multivariable regression analyses revealed that Δ V · E/Δ V · CO2(PEAK)