Clinical Significance Of Radiological Markers Of Pulmonary Hypertension In Combined Pulmonary Fibrosis And Emphysema

SESSION TITLE: Updates in Diffuse and Orphan Lung Diseases SESSION TYPE: Original Investigations PRESENTED ON: October 18-21, 2020 PURPOSE: Combined Pulmonary Fibrosis and Emphysema (CPFE) is characterized by upper lobe emphysema and lower lobe fibrosis with relative preservation of lung volumes and severely reduced gas exchange. Pulmonary hypertension (PH) is associated with decreased survival in CPFE with PH. Pulmonary artery (PA) diameter, PA diameter/Ascending aortic diameter (PA/A) ratio, and Right inferior pulmonary vein (RIPV) diameter as measured on CT have recently emerged as specific markers for PH. Our study attempts to describe the relationship of these CT markers to PH and mortality in CPFE. METHODS: We performed a single-center, longitudinal retrospective cohort study of individuals hospitalized at the Providence VA Medical Center over a ten-year study period from 1st April 2008-1st April 2018 with a discharge diagnosis referencing pulmonary fibrosis. Subjects were excluded if they had no CT imaging, nonspecific ground glass changes only, or other conditions that could alter PA diameter. The study population was then divided into two groups, CPFE and idiopathic pulmonary fibrosis (IPF), by the presence of emphysema. Demographic and clinical data were collected by chart review at diagnosis and last follow up. Measurements of PA, Ascending aorta, RIPV, and Left Ventricle Short Axis (LVSA) diameter were made by a thoracic radiologist. Development of PH was defined as an estimated Right Ventricular Systolic Pressure (RVSP) >50mmHg. Survival analysis was performed using a Log-rank test and Kaplan Meier analysis. A Cox Proportional Hazard model or ANOVA test was used for the analysis of other variables. RESULTS: Eighty-two patients met inclusion criteria: CPFE (n=33) and IPF(n=49). The mean follow-up period was 31 months for the IPF group and 44 months for the CPFE group. PA/A ratio>1 was associated with decreased survival in the study population (p=0.015). Presence of honeycombing (Hazard Ratio 2.20, 95% CI [1.31,3.67]), traction bronchiectasis (Hazard Ratio 2.02, 95% CI [1.15, 3.55]), and ground glass changes (Hazard Ratio 0.58, 95% CI [0.34, 0.98]) on CT correlated with increased mortality for the study population. Corrected for age and body surface area, RIPV diameter (Correlation coefficient 6.44, 95% CI [14.99, 17.24]), and LVSA diameter (Correlation coefficient 10.66, 95% CI [42.24, 43.43]) at diagnosis were associated with the development of PH in the CPFE group. CONCLUSIONS: PA/A ratio>1 is associated with decreased survival in the study population. RIPV diameter and LVSA diameter at diagnosis are associated with the development of PH in CPFE patients, but PA diameter and PA/A ratio are not. CLINICAL IMPLICATIONS: The ability to quantify pulmonary hypertension by non-invasive methods provides valuable prognostic information in CPFE. DISCLOSURES: No relevant relationships by Michael Atalay, source=Web Response No relevant relationships by Fenghai Duan, source=Web Response No relevant relationships by Matthew Jankowich, source=Web Response No relevant relationships by Juraj Melek, source=Web Response No relevant relationships by Sharon Rounds, source=Web Response No relevant relationships by Yanning Wu, source=Web Response No relevant relationships by Fatima Zeba, source=Web Response