Cardiopulmonary exercise factors predict survival in patients with advanced interstitial lung disease referred for lung transplantation

Background: The purpose of this work was to determine if parameters assessed during Cardiopulmonary Exercise Testing (CPET) while using supplemental oxygen can independently predict one-year transplant- free survival in patients with Interstitial Lung Disease (ILD) referred for lung transplant evaluation. Methods: We performed a chart review of patients with ILD who completed CPET with 30% FiO(2) and gathered spirometry, pulmonary hemodynamic, six-minute walk, and CPET data. The primary end-point was death or lung transplantation within one-year of CPET. Results: The final data set included 192 patients. 79 patients died/underwent transplant, 113 survived transplant-free. Multivariable Cox regression revealed peak workload % predicted, nadir CPET SpO(2), and FVC% predicted as independent predictors of one-year transplant-free survival. Of the independent predictors of survival, receiver operating characteristics analysis revealed peak workload % predicted cutoff of 35% to be highly discriminatory, more so than nadir CPET SpO(2) or FVC % predicted in identifying patients at risk for one-year mortality or transplant (peak workload % predicted < 35% HR = 4.71, 95% CI = 2.64-8.38 and area under the curve (AUC) = 0.740, nadir CPET SpO(2) < 86% HR = 2.27, 95% CI = 1.41 -3.68, AUC = 0.645, FVC % predicted < 45% HR = 1.82, 95% CI = 1.15-2.87, AUC = 0.624). Conclusion: Peak workload % predicted, nadir CPET SpO2, and FVC% predicted in ILD patients referred for lung transplant evaluation are independently predictive of one-year mortality or need for transplant. c 2017 Elsevier Ltd. All rights reserved.