Idiopathic pulmonary fibrosis patients with severe physiologic impairment: characteristics and outcomes

• Main Authors: Jean Pastre, Scott Barnett, Inga Ksovreli, Jeannie Taylor, A. Whitney Brown, Oksana A. Shlobin, Kareem Ahmad, Vikramjit Khangoora, Shambhu Aryal, Christopher S. King, Steven D. Nathan
• Format: Article
• Language: English
• Published: BMC 2021-01-01
• Series: Respiratory Research
• Subjects: Idiopathic pulmonary fibrosis; Pulmonary function test; 6-min walk test; Transplant-free survival; Hospitalization; Antifibrotic therapies
• Online Access: https://doi.org/10.1186/s12931-020-01600-z

Abstract Research question There is no widely accepted grading system for IPF disease severity, although physiologic impairment based on pulmonary function testing is frequently employed. We sought to describe clinical and functional characteristics as well as outcomes of patients with severe physiologic impairment. Patients and methods IPF patients with severe physiologic impairment defined by FVC ≤ 50% and/or DLco ≤ 30% predicted evaluated in the Inova Advanced Lung Disease Program between 2011 and 2019 were included. Demographic, physiologic, functional treatment and outcome data were collated. Results There were 531 patients with IPF evaluated of whom 242 (46%) had severe physiologic impairment. Mean age was 72 ± 8 years; baseline FVC was 53 ± 17% and DLCO 28 ± 9% of predicted. The mean 6 min walks test (6MWT) distance was 304 ± 121 m with 59% of the patients requiring supplemental oxygen ( $${\text{6MWT}}_{{{\text{O}}_{{2}} }}$$ 6MWT O 2 group). There was a poor correlation between the 6MWT distance and both FVC% and DLco%. Patients in the 6MWTRA group had a better transplant-free survival than the $${\text{6MWT}}_{{{\text{O}}_{{2}} }}$$ 6MWT O 2 group (p = 0.002). Patients managed before October 2014 and not receiving antifibrotic therapy had worse outcomes with reduced transplant-free survival compared with patients presenting after this date who did receive antifibrotic therapy (n = 113) (log rank p < 0.0001). Conclusion IPF patients often present with severe physiologic impairment which may be poorly correlated with their functional status. Assessment of IPF disease severity should not be based on physiologic impairment alone, but should also encompass functional status as well as need for supplemental oxygen. Antifibrotic therapy in patients with severe physiologic impairment is associated with improved outcomes.