Authors: An Zhao, Eyjolfur Gudmundsson, Nesrin Mogulkoc, Coline van Moorsel, Tamera J. Corte, Pardeep Vasudev, Chiara Romei, Robert Chapman, Tim J.M. Wallis, Emma Denneny, Tinne Goos, Recep Savas, Asia Ahmed, Christopher J. Brereton, Hendrik W. van Es, Helen Jo, Annalisa De Liperi, Mark Duncan, Katarina Pontoppidan, Laurens J. De Sadeleer, Frouke van Beek, Joseph Barnett, Gary Cross, Alex Procter, Marcel Veltkamp, Peter Hopkins, Yuben Moodley, Alessandro Taliani, Magali Taylor, Stijn Verleden, Laura Tavanti, Marie Vermant, Arjun Nair, Iain Stewart, Sam M. Janes, Alexandra L. Young, David Barber, Daniel C. Alexander, Joanna C. Porter, Athol U. Wells, Mark G. Jones, Wim A. Wuyts, Joseph Jacob
Published: 2023-11-16
DOI: 10.1183/13993003.00127-2023
Source: Full article
BackgroundIdiopathic pulmonary fibrosis (IPF) with coexistent emphysema, termed combined pulmonary fibrosis and emphysema (CPFE) may associate with reduced forced vital capacity (FVC) declines compared to non-CPFE IPF patients. We examined associations between mortality and functional measures of disease progression in two IPF cohorts.MethodsVisual emphysema presence (>0% emphysema) scored on computed tomography identified CPFE patients (CPFE/non-CPFE: derivation cohort n=317/n=183, replication cohort n=358/n=152), who were subgrouped using 10% or 15% visual emphysema thresholds, and an unsupervised machine-learning model considering emphysema and interstitial lung disease extents. Baseline characteristics, 1-year relative FVC and diffusing capacity of the lung for carbon monoxide (DLCO) decline (linear mixed-effects models), and their associations with mortality (multivariable Cox regression models) were compared across non-CPFE and CPFE subgroups.ResultsIn both IPF cohorts, CPFE patients with ≥10% emphysema had a greater smoking history and lower baselineDLCOcompared to CPFE patients with <10% emphysema. Using multivariable Cox regression analyses in patients with ≥10% emphysema, 1-yearDLCOdecline showed stronger mortality associations than 1-year FVC decline. Results were maintained in patients suitable for therapeutic IPF trials and in subjects subgrouped by ≥15% emphysema and using unsupervised machine learning. Importantly, the unsupervised machine-learning approach identified CPFE patients in whom FVC decline did not associate strongly with mortality. In non-CPFE IPF patients, 1-year FVC declines ≥5% and ≥10% showed strong mortality associations.ConclusionWhen assessing disease progression in IPF,DLCOdecline should be considered in patients with ≥10% emphysema and a ≥5% 1-year relative FVC decline threshold considered in non-CPFE IPF patients.