A role for cardiopulmonary exercise testing in detecting physiological changes underlying health status in Idiopathic pulmonary fibrosis: a feasibility study

Abstract

Introduction There is limited data available on the use of CPET as a predictive tool for disease outcomes in the setting of IPF. We investigated the feasibility of undertaking CPET and the relationship between CPET and quality of life measurements in a well-defined population of mild and moderate IPF patients. Methods A prospective, single-centre observational study. Results Thirty-two IPF patients (mild n = 23, moderate n = 9) participated in the study, n = 13 mild patients attended for repeat CPET testing at 12 months. At baseline, total K-BILD scores and total IPF-PROM scores significantly correlated with 6MWT distance, but not with baseline FVC % predicted, TLco % predicted, baseline or minimum SpO2. VO2 peak/kg at AT positively correlated with total scores, breathlessness/activity and chest domains of the K-BILD questionnaire (p < 0.05). VO2 peak significantly correlated with total IPF PROM scores and wellbeing domains (p < 0.05), with a trend towards statistical significance for total IPF-PROM and VO2 peak/kg at anaerobic threshold (p = 0.06). There was a statistically significant reduction in FVC% predicted at 12 months follow up, although the mean absolute decline was < 10% (p < 0.05). During this period VO2 peak significantly reduced (21.6 ml/kg/min ± 2.9 vs 19.1 ± 2.8; p = 0.017), with corresponding reductions in total K-BILD and breathlessness/activity domains that exceeded the MCID for responsiveness. Lower baseline VO2 peak/kg at anaerobic threshold correlated with greater declines in total K-BILD scores (r = − 0.62, 0.024) at 12 months. Whilst baseline FVC% predicted or TLco % predicted did not predict change in health status, Conclusion We have shown that it is feasible to undertake CPET in patients with mild to moderate IPF. CPET measures of VO2 peak correlated with both baseline and change in K-BILD measurements at 1 year, despite relatively stable standard lung function (declines of < 10% in FVC), suggesting its potential sensitivity to detect physiological changes underlying health status.