Elucidation of prognostic factors and the effect of anti-fibrotic therapy on waitlist mortality in lung transplant candidates with idiopathic interstitial pneumonias.

BACKGROUND Lung transplantation (LTx) is the last resort for patients who fail to respond to drug therapy and progress to advanced idiopathic interstitial pneumonias (IIPs). However, more than one-third of patients registered for LTx face despair because of rapid disease progression and donor shortage. This study aimed to identify the risk factors of waitlist mortality in LTx candidates with IIPs and investigate the association of anti-fibrotic therapy with waitlist mortality. METHODS We retrospectively investigated 56 patients with IIPs, including 29 patients with idiopathic pulmonary fibrosis (51.7%) and 11 patients with idiopathic pleuroparenchymal fibroelastosis (19.6%), registered for LTx at Fukuoka University Hospital between January 2006 and June 2020. The risk factors affecting transplantation-censored survival were evaluated. RESULTS The waitlist mortality rate of patients with nonspecific interstitial pneumonia was significantly lower than that of others. Multivariate survival analysis using Cox's model identified a history of pneumothorax (P = 0.029) and short 6-min walk distance (6MWD) (P = 0.012) to be significant variables affecting waitlist mortality. Patients receiving anti-fibrotic therapy (n = 27, 48.2%) had a lower risk of pneumothorax (P = 0.017) and their 6MWD was longer than that of non-therapy patients (P < 0.001). The waitlist mortality rate of patients on anti-fibrotic therapy was significantly lower (P = 0.012). CONCLUSIONS History of pneumothorax and short 6MWD were independent predictors of waitlist mortality in LTx candidates with IIPs. The anti-fibrotic therapy may potentially reduce mortality in patients with IIPs on the waiting list for LTx.