The Fitter the Better? Cardiopulmonary Exercise Testing Can Predict Pulmonary Exacerbations in Cystic Fibrosis

Asterios Kampouras; Elpis Hatziagorou; Thomas Kalantzis; Vasiliki Avramidou; Kalliopi Kontouli; Fotios Kirvassilis; John Tsanakas

doi:10.3390/children8060527

The Fitter the Better? Cardiopulmonary Exercise Testing Can Predict Pulmonary Exacerbations in Cystic Fibrosis

Children (Basel). 2021 Jun 21;8(6):527. doi: 10.3390/children8060527.

Authors

Asterios Kampouras¹, Elpis Hatziagorou¹, Thomas Kalantzis², Vasiliki Avramidou¹, Kalliopi Kontouli¹, Fotios Kirvassilis¹, John Tsanakas¹

Affiliations

¹ Pediatric Pulmonology and CF Unit, 3rd Department of Paediatrics, Hippokration Hospital, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
² Hellenic Statistics Authority, 185 10 Piraeus, Greece.

Abstract

Background: The role of cardiopulmonary exercise testing (CPET) in the assessment of prognosis in CF (cystic fibrosis) is crucial. However, as the overall survival of the disease becomes better, the need for examinations that can predict pulmonary exacerbations (PEx) and subsequent deterioration becomes evident.

Methods: Data from a 10-year follow up with CPET and spirometry of CF patients were used to evaluate whether CPET-derived parameters can be used as prognostic indexes for pulmonary exacerbations in patients with CF. Pulmonary exacerbations were recorded. We used a survival analysis through Cox Regression to assess the prognostic role of CPET parameters for PeX. CPET parameters and other variables such as sputum culture, age, and spirometry measurements were tested via multivariate cox models.

Results: During a 10-year period (2009-2019), 78 CF patients underwent CPET. Cox regression analysis revealed that VO₂peak% (peak Oxygen Uptake predicted %) predicted (hazard ratio (HR), 0.988 (0.975, 1.000) p = 0.042) and PetCO₂ (end-tidal CO₂ at peak exercise) (HR 0.948 (0.913, 0.984) p = 0.005), while VE/VO₂ and (respiratory equivalent for oxygen at peak exercise) (HR 1.032 (1.003, 1.062) p = 0.033) were significant predictors of pulmonary exacerbations in the short term after the CPET. Additionally, patients with VO₂peak% predicted <60% had 4.5-times higher relative risk of having a PEx than those with higher exercise capacity.

Conclusions: CPET can provide valuable information regarding upcoming pulmonary exacerbation in CF. Patients with VO₂peak <60% are at great risk of subsequent deterioration. Regular follow up of CF patients with exercise testing can highlight their clinical image and direct therapeutic interventions.

Keywords: cystic fibrosis; exercise testing; prognosis; pulmonary exacerbation.