Cheng YY; Veterans General Hospital, Taichung 40705, Taiwan.
Lee YC; Liao YW; Liu MC; Wu YC; Hsu CY; Yu YH; Fu PK

Respiratory Care. 69(10):1305-1313, 2024 Sep 26.

BACKGROUND: Cardiopulmonary exercise testing (CPET) is a unique diagnostic
tool that assesses the functional capacity of the heart, lungs, and
peripheral oxidative system in an integrated manner. However, the clinical
utility of CPET for evaluating interstitial lung disease (ILD) remains
uncertain. The objective of this study was to determine the predictive
value of CPET for mortality in subjects with ILD.
METHODS: We prospectively enrolled subjects with ILD who underwent CPET
at a tertiary medical center in Taiwan and followed up their survival
status for 12 months. Mortality prediction was based on comparing CPET
parameters between subjects who survived and those who died. We further
analyzed CPET parameters that showed significant differences using
receiver operating characteristic curves to identify their optimal cutoff
values.
RESULTS: A total of 106 newly diagnosed subjects with ILD underwent CPET,
and the 1-y mortality rate was 7.5%. Six CPET variables were found to be
significant predictors of mortality: peak oxygen consumption, oxygen
pulse, end-tidal partial pressure of carbon dioxide, heart rate recovery 1
min after CPET, minute ventilation to carbon dioxide output slope, and
functional aerobic impairment. We calculated a summed score by adding the
number of CPET variables that exceeded their cutoff values. Subjects with
a summed score of 6 had a 1-y survival rate of only 25%, whereas subjects
with scores of 0-5 had a survival rate of 98%.
CONCLUSIONS: In conclusion, the summed score represents a useful tool for
screening patients with ILD who can undergo a CPET to determine their
prognosis.