Prognostic Value of a Cardiopulmonary Exercise Testing-Derived Summed Score in Idiopathic Pulmonary Fibrosis and Connective Tissue Disease-Associated Interstitial Lung Disease: A Prospective Cohort Study.

BACKGROUND AND

OBJECTIVE

Our previous study demonstrated that a summed score derived from six cardiopulmonary exercise testing (CPET) parameters could predict 1-year mortality in patients with interstitial lung disease (ILD). However, its long-term prognostic value across different ILD aetiologies remains unclear. This study aimed to assess the predictive performance of CPET-derived parameters for long-term outcomes in patients with idiopathic pulmonary fibrosis (IPF) and connective tissue disease-associated ILD (CTD-ILD).

METHODS

In this prospective cohort study, 210 patients newly diagnosed with ILD between 2018 and 2022 at a tertiary medical centre underwent CPET. A CPET-derived summed score was evaluated for its association with a composite outcome of all-cause mortality or lung transplantation. Cox regression and receiver operating characteristic curve analyses were used to examine predictive ability and identify the optimal cutoff value. Kaplan-Meier survival analysis and log-rank tests compared event-free survival in IPF and CTD-ILD patients.

RESULTS

A summed score incorporating five CPET-derived variables was an independent predictor of the composite outcome. Patients with scores of 2-5 had markedly lower event-free survival (44.2%) than those with scores of 0-1 (88.3%). The score demonstrated consistent predictive value in both IPF and CTD-ILD.

CONCLUSION

The CPET-derived summed score is a useful prognostic tool for predicting all-cause mortality or the need for lung transplantation in newly diagnosed ILD patients. It also retains predictive accuracy for long-term outcomes in both IPF and CTD-ILD. External validation in other ILD subtypes is warranted.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT06476470.