Background: Interstitial lung disease (ILD) can cause significant morbidity and mortality. A cardiopulmonary exercise test (CPET) predicts mortality risk in patients with congestive heart failure and dilated cardiomyopathy. In patients with newly diagnosed IPF, however, CPET is not routinely used as a diagnostic or monitoring tool. A limited amount of research has also been conducted regarding the prognostic value of CPET in ILD.

Methods: During December 2018 and August 2021, patients with newly diagnosed ILD were recruited and CPET were performed. We tracked mortality prospectively for one year. Parameters of the CPET were compared among survivors and deceased within one year. To determine the cutoff points, receiver operating characteristic curve analysis was conducted on the significantly different parameters.

Results: W enrolled 106 patients with ILD. Significant predictors of mortality were identified for six CPET variables, including peak oxygen consumption, oxygen pulse, peak end-tidal partial pressure of carbon dioxide, heart rate recovery one minute after CPET, minute ventilation to carbon dioxide output slope, and functional aerobic impairment. We calculated a summed score, which represents the number of CPET variables above the cutoff values. In this summed score, patients scoring 6 had a 25% one-year survival rate, compared with 97.96% for patients scoring 0-5.

Conclusion: The CPET is recommended for all patients who have been newly diagnosed with ILD. A combined score from CPET can be used to predict prognosis for these populations.