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

- CPET parameters were predictive of one-year prognosis in patients with ILD.
- Peak workload was highly discriminatory in identifying ILD patients at risk.
- Nadir SpO2% obtained during CPET identified ILD patients with reduced prognosis.
- Future work may use these results to create a predictive model.

BackgroundThe 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.MethodsWe performed a chart review of patients with ILD who completed CPET with 30% FiO2 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.ResultsThe final data set included 192 patients. 79 patients died/underwent transplant, 113 survived transplant-free. Multivariable Cox regression revealed peak workload % predicted, nadir CPET SpO2, 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 SpO2 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 SpO2 < 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).ConclusionPeak 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.