B41-04 Dissociation Between Hemodynamic and Spirometric Progression in Listed Idiopathic Pulmonary Fibrosis Patients: A Single-Center Pilot Analysis

Abstract Rationale Pulmonary hypertension (PH) is a common complication of idiopathic pulmonary fibrosis (IPF) and is linked to poorer transplant outcomes. Recent findings by Nathan et al. demonstrated progressive increases in mean pulmonary artery pressure (mPAP) during waitlist periods among patients with IPF. The present study investigated whether worsening PH is accompanied by a decline in pulmonary function within a single-center cohort. Methods A retrospective review was performed on 10 patients with IPF listed for lung transplantation at Temple University. Each patient underwent right heart catheterization (RHC) at the time of listing and again intra-operatively at transplant. Forced vital capacity (FVC, liters) was measured at both time points. Pulmonary function tests (PFTs) were conducted a mean of 6.3 days from listing RHC (range: 3-28 days) and a mean of 28.4 days before transplant RHC (range: 7-51 days). The mean interval between RHCs, representing the transplant waitlist duration, was approximately 165 ± 78 days. Absolute differences in FVC and mPAP between time points were calculated. Paired statistical tests assessed changes, and Spearman’s correlation evaluated the association between changes in FVC and mPAP. Results The mean FVC was 2.22 ± 0.65 L at listing and 2.16 ± 0.73 L at transplant (change in FVC = −0.058 L; p = 0.54). Mean mPAP increased from 23.2 ± 7.6 mmHg to 33.9 ± 9.5 mmHg (change in mPAP = +10.7 mmHg; p = 0.001). At listing, 6 of 10 patients had mPAP greater than 20 mmHg (pre-capillary PH), increasing to 9 of 10 at transplant. No significant correlation was observed between ΔFVC and ΔmPAP (ρ = 0.15). Conclusions In this pilot cohort, mPAP increased significantly from listing to transplant, while FVC demonstrated considerable variability without a consistent trend. Changes in FVC were not correlated with PH progression. These results suggest that physiologic and hemodynamic decline may diverge in advanced IPF. Serial RHC may offer essential insights not captured by spirometry alone. Larger studies are warranted to confirm these findings and further clarify the relationship between pulmonary function and hemodynamic progression in IPF. This abstract is funded by: None