PURPOSE: Idiopathic pulmonary fibrosis (IPF) remains associated with significant mortality, but predictors of mortality in IPF are poorly understood. Pulmonary hypertension (PH) has emerged as a common complication of IPF; however, the impact of PH on survival is also unclear.
METHODS: We reviewed the records of patients with IPF listed for lung transplant (LT) in the US between Jan. 1995 and June 2004 to identify those with data available from right heart catheterization (RHC). We defined PH as a mean pulmonary artery (PA) pressure of ≥25 mmHg. We excluded persons with pulmonary capillary wedge pressures ≥15 mmHg. Survival after listing (with or without LT) represented the primary endpoint, while probability of LT served as a secondary endpoint. Patients with PH were compared to those with normal PA pressures with respect to multiple potential confounders (e.g., demographics, lung function, co-morbidities).
RESULTS: Of 2972 patients listed, 2075 (69.8%) had undergone RHC. PH was noted in 39.1% of subjects. Unadjusted median survival in persons with PH was 18.8 months. Only 44.6% of those with PH were alive two years after listing compared to 61.3% of those without PH (p<0.0001). In a Cox proportional hazard model adjusting for demographics, year of listing, lung function, need for supplemental oxygen, performance status, underlying diseases, and cardiac index, having PH remained associated with mortality. Those with PH were 1.62 times (95% CI: 1.43-1.84) more likely to die after being listed for LT.
CONCLUSION: PH is common in IPF. Patients with PH complicating IPF are at significantly increased risk for death, and the risk is independent of multiple potential confounders. Because of this subtantial risk for mortality, subjects with PH and IPF disproportionately die after being listed for LT.
CLINICAL IMPLICATIONS: Physicians should consider evaluating those with IPF for PH and not delay listing for LT those with IPF and PH early in their disease course. Because of its association with mortality, trials for therapies for PH in IPF appear warranted.
DISCLOSURE: Andrew Shorr, No Financial Disclosure Information; No Product/Research Disclosure Information