[Prognostic value of clinical exercise testing in adult patients with cystic fibrosis].

Background: Current guidelines for referring cystic fibrosis (CF) patients for lung transplantation, based on resting parameters, are insufficient to predict 3-year mortality. The aim of this study was to determine the prognostic value of cardiopulmonary exercise testing (CPET) in adult CF patients.

Methods: A multicenter retrospective study on 3-year outcomes was made on 51 adult CF patients who underwent CPET with blood gas analysis. Demographic data, resting pulmonary function and CPET parameters were collected to perform a univariate survival analysis by Kaplan-Meier curves and log-rank tests. To estimate prognosis, a multivariate logistic regression analysis was performed.

Results: The survival log-rank analysis indicated that lower FEV(1), lower body mass index (BMI), diabetes mellitus, lower work rate and higher alveolar-arterial gradient for oxygen (P[A-a]O(2)) at peak exercise were associated with a significantly higher risk of death. The logistic regression analysis showed that BMI (<19.8) and P(A-a)O(2) peak (>43 mmHg) were independently associated with a lower chance of survival.

Conclusion: CPET with blood gas analysis may have a prognostic value in adult CF patients. Further larger prospective clinical studies are warranted to confirm these preliminary results.