Predicting survival of lung transplantation candidates with idiopathic interstitial pneumonia: does PaO(2) predict survival?

Objective: To find a parameter that would discriminate between the patients with idiopathic interstitial pneumonia who survived to undergo transplantation and those who died while waiting to undergo transplantation.

Methods: A retrospective review was performed of all lung transplant referrals for idiopathic interstitial pneumonia that were listed with United Network for Organ Sharing at the University of California San Diego from January 1990 to February 1999. Of the 331 patients who were listed, 48 met the eligibility criteria. Patient demographics, radiographic studies, pathology reports, and the results of resting and exercise cardiopulmonary function tests were recorded from each patient's chart. Patients were divided into the following two groups: those patients who survived until transplantation and those still waiting were classified as "alive"; and those patients who died before undergoing transplantation were classified as "deceased."

Results: Forty-three of 48 patients had a pathologic diagnosis. The cohort included 25 patients with usual interstitial pneumonitis, 3 patients with nonspecific interstitial pneumonitis, 1 patient with desquamative interstitial pneumonitis, and 14 patients with interstitial lung disease of unknown etiology. The only significant difference between the two groups was resting PaO(2) (p = 0.035). A stepwise multivariate analysis demonstrated that PaO(2) and FEV(1)/FVC ratio were significantly associated with survival (hazards ratio, 1.06; confidence interval, 0.99 to 1.13; p = 0.019).

Conclusions: A survival analysis using PaO(2) and FEV(1)/FVC ratio values proved to be statistically significant, but a prospective trial is needed to determine the clinical relevance of these parameters for predicting survival in patients with idiopathic interstitial pneumonia.