Prognostic Role and Determinants of Ascending Aorta Dilatation in Non-Advanced Idiopathic Pulmonary Fibrosis: A Preliminary Observation from a Tertiary University Centre

Background: No previous study was specifically focused on the ascending aorta (AA) diameter assessment in patients with idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the prognostic role of the AA diameter in patients with mild-to-moderate IPF and to identify the main determinants of the AA dilatation. Methods: All IPF patients without severe pulmonary hypertension who underwent a multi-instrumental evaluation, comprehensive of high-resolution computed tomography (HRCT) and transthoracic echocardiography (TTE), between September 2017 and No-vember 2023, were retrospectively analyzed. The primary endpoint was the composite of “all-cause mortality or re-hospitalization for all causes”, over a medium-term follow-up. The secondary endpoint was to evaluate the independent predictors of AA dilatation. Additionally, Bland-Altman analysis was used to assess the accuracy and precision of echocardiography-derived AA diameters compared with non-ECG gated HRCT meaurements. Results: A total of 105 IPF patients and 102 age-, sex- and cardiovascular risk factors-matched controls without IPF were retrospectively evaluated. Over a follow-up of 3.9±1.9 yrs, 31 patients died and 47 were re-hospitalized. AA/height (HR 1.15, 95% CI 1.06-1.25, p < 0.001) was independently associated with the primary endpoint, whereas unindexed AA (HR 1.01, 95% CI 0.96-1.06, p = 0.83) and AA/BSA (HR 1.00, 95% CI 0.89-1.11, p = 0.39) were not. An AA/height >20 mm/m showed 100% sensitivity and 63% specificity (AUC = 0.78) for predicting the primary endpoint. C-reactive protein (OR 1.87; 95% CI 1.21-2.89, p = 0.005) and left ventricular mass index (OR 1.13, 95% CI 1.04-1.24, p = 0.006) were independently associated with an AA/height >20 mm/m in the whole study group. The Bland-Altman analysis revealed a bias of +2.51 mm (with the 95% limits of agreement ranging –3.62 to 8.65 mm) for AA estimation, suggesting a general overestimation of the AA diameter by TTE in comparison to HRCT. Conclusions: The AA dilatation is predictive of poor outcome in IPF patients without advanced lung disease, over a mid-term follow-up. The AA/height assessment may improve the prognostic risk stratification of IPF patients.