Prognostic Value of Cardiopulmonary Exercise Test, Pulmonary Function Test , and Questionnaires on Mortality in Patients With Idiopathic Pulmonary Fibrosis: A Prospective Pilot Study

Background and Objective: Idiopathic pulmonary fibrosis (IPF) is a lung disease with a high mortality rate. Finding an effective predictor of survival is therefore important for clinicians and patients. Several parameters have been established to predict mortality, but none of these have been validated in the Asian population. In this study, we evaluated the prognostic value of the parameters of cardiopulmonary exercise test (CPET), pulmonary function test (PFT), 6-min walk test (6MWT), and certain questionnaires on mortality in Asian patients with IPF. Methods: This prospective observational study analysed patient data, including age, gender, height, and body weight; scores of Saint George’s Respiratory Questionnaire (SGRQ), Modified Medical Research Council (mMRC) for dyspnoea, and Short Form-36 (SF-36); and parameters of PFT, 6MWT, and CPET. Results: In total, 24 patients diagnosed as having IPF were followed up for 14 months, during which 3 patients died. The nonsurvivors had significantly lower body weight; lower forced vital capacity (FVC); higher ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC); higher gender, age, and pulmonary physiology (GAP) index; shorter walk distance in 6MWT; lower end-tidal pressure of carbon dioxide (DLCO); higher functional aerobic impairment (FAI) during exercise; and higher mMRC score. FEV1/FVC, FAI, GAP index, and mMRC dyspnoea score demonstrated an area under curve (AUC) of >0.7, and the corresponding cut-off values were 89%, 54%, 7, and 3. Conclusions: The predictive abilities of PFT, CPET, and mMRC scores were validated successfully in the study cohort of Asian patients with IPF.