B79-06 Temporal Relationship Between Hemodynamic Progression and Quantitative Computed Tomography (CT) Remodeling in Idiopathic Pulmonary Fibrosis (IPF) Lung Transplant Candidates

Abstract Rationale Pulmonary hypertension is a common complication of idiopathic pulmonary fibrosis (IPF), contributing to disease progression and increased mortality among patients awaiting transplantation. Right heart catheterization (RHC) quantitatively assesses pulmonary vascular load, while quantitative computed tomography (CT) provides objective metrics of fibrotic remodeling. The temporal relationship between these measures prior to transplantation, however, remains insufficiently characterized. Methods A retrospective analysis was conducted on 10 IPF lung transplant recipients who underwent serial RHCs and paired quantitative CT assessments using the artificial intelligence software Coreline Soft® (Coreline) at listing and prior to transplantation. Coreline analysis quantified parenchymal composition, including honeycombing, reticulation, ground-glass opacities (GGOs), consolidation, emphysema, and normal lung fraction. Within-subject changes were evaluated using the Wilcoxon signed-rank test, and correlations between changes in mean pulmonary artery pressure (mPAP) and imaging metrics were assessed with Pearson correlation coefficients. The mean interval between RHCs was 176 days (range 33-653), reflecting the average waitlist duration for transplants. Coreline studies were performed within a mean of 14 days (range 1-83) of each corresponding RHC. Results Mean pulmonary artery pressure (mPAP) increased from 23.8 (14-48) to 37.3 (22-51) mmHg, an average rise of 13.5 mmHg (p 0.05). Quantitative imaging demonstrated increases in honeycombing (4.2% to 8.8%, p = 0.25), reticulation (16.4% to 20.5%, p = 0.43), and ground-glass opacities (13.1% to 21.6%, p = 0.11), while consolidation and emphysema remained stable. None of these changes reached statistical significance. The percentage of normal lung declined significantly (60.7% to 43.5%, p 0.05) (Table 1). Correlations between changes in mPAP and imaging metrics were weak and not statistically significant. Correlation coefficients (r 95% CI, p) were as follows: honeycombing −0.01 −0.63, 0.63, reticulation −0.35 −0.80, 0.36, ground-glass 0.31 −0.40, 0.79, consolidation 0.35 −0.36, 0.80, emphysema −0.49 −0.85, 0.21, and normal lung −0.33 −0.79, 0.38; all p 0.1. The wide confidence intervals indicate substantial inter-individual variability. Conclusions During a median six-month waitlist period, IPF transplant candidates demonstrated worsening hemodynamics, increased fibrosis, and a reduction in normal lung fraction. Although changes in mPAP paralleled fibrotic progression, correlations were not statistically significant, likely due to the small sample size. Larger studies are necessary to more accurately evaluate the relationships between hemodynamics and imaging in this population. This abstract is funded by: None