Tsai YL; Veterans General Hospital, Taichung City, Taiwan.
Chang KM; Chin CS; Hsu CY; Yu YH; Cheng YY; Fu PK

Respirology. 31(5):498-508, 2026 May.

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.