Study objectives: Diffuse parenchymal lung disease is associated with a high risk of mortality despite early referral and listing for lung transplantation. We hypothesized that cardiopulmonary exercise test results and the distance walked in 6min (6MWTD) would be associated with survival in patients with diffuse parenchymal lung disease referred for lung transplantation.
Design: Retrospective cohort study.
Setting: Tertiary care center.
Patients: We included 51 consecutive patients with diffuse parenchymal lung disease who underwent exercise testing after referral to the Lung Transplant Program at the New York Presbyterian Hospital between January 2000 and December 2002. Thirty-three patients were listed, and 7 underwent transplantation during the study period. There were 17 deaths with 1 death post-transplantation.
Results: A 6MWTD < 350 m was associated with an increased risk of death (HR = 4.6, 95% CI 1.5-14.2, P = 0.009). Oxygen saturation with unloaded exercise (HR = 0.91, 95% CI 0.84-0.98, P = 0.015) and oxygen consumption at peak exercise adjusted for weight (HR = 0.88, 95% CI 0.79-0.99, P = 0.039) were also associated with the risk of death. A patient with oxygen saturation <95% during unloaded exercise had a 75% chance of dying on the list for transplantation. A patient with 6MWTD < 350 m had a 67% chance of dying on the list.
Conclusions: Cardiopulmonary exercise test parameters and the 6MWTD were associated with the risk of death. Measures during exercise may be useful for determination of prognosis and for prioritizing patients with diffuse parenchymal lung disease for lung transplantation.