LAUSR

Background: Cardiopulmonary Exercise Testing (CPET) in patients suffering from chronic obstructive pulmonary disease (COPD) has already proved his value for the assessment of prognosis in such patients, especially through the peak oxygen uptake (peak V’O2). Aim: To assess if V’O2 measured at ventilatory threshold is efficient to predict mortality in COPD patients Methods: Data were available from two cohorts in a university hospital centre in France. COPD patients which have performed a CPET at the beginning of a pulmonary rehabilitation program between 2008 and 2018 were included. Results: Among 104 patients included, 29 died during their follow-up. The V’O2 at the ventilatory threshold, expressed in percentage of the predicted peak V’O2, was identified as a prognostic factor (HR 0.954, 95% ci : 0.921 - 0.989). In a multivariable logistic regression model, including sex, age, heart failure and negative chronotropic treatment, this variable remained associated with mortality (HR 0.944, 95% CI 0.908 - 0.982). The peak V9O2 (percentage reference value) was also associated with mortality as expected (HR 0.953, IC95% 0.924 - 0.982). Conclusion: V’O2 measured at the ventilatory threshold could be one of the best criterion to predict mortality. It has the advantage to be obtain in sub-optimal conditions, less influence by patient motivation. Further analyses are in progress to confirme this preliminary results and to determine the optimal threshold.