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Updated: Aug 10, 2026
Establishment and Validation of a Rat Model of Pulmonary Arterial Hypertension Associated with Pulmonary Fibrosis
Published on: May 23, 2025
Development and internal validation of a nomogram to predict pulmonary hypertension in fibrosing interstitial lung
David Rodríguez-Plaza1,2,3, Jesús Ribas4,5, Isabel Alfaya4,5
1Respiratory Department, Bellvitge University Hospital, Barcelona, Spain. drodriguezp@bellvitgehospital.cat.
Background:
Pulmonary hypertension (PH) is a common comorbidity in patients with interstitial lung disease (ILD), with a negative prognostic impact. The main objective of this study was to develop and internally validate a nomogram to predict PH using real-life data from patients with fibrosing ILD.
Methods:
Retrospective, cross-sectional, single-centre study including adult patients with a diagnosis of fibrosing ILD undergoing right heart catheterization (RHC). Bootstrap was used to select clinical, radiological, and functional predictors of precapillary PH. LASSO, Elastic Net, and CART were also performed to enhance robustness. The final model was presented using a nomogram and PH risk was stratified into three categories according to CART.
Results:
Ninety patients were included. The most frequent ILD diagnoses were idiopathic pulmonary fibrosis (20%), connective tissue diseases-ILD (18.9%) and combined pulmonary fibrosis and emphysema (17.8%). Echocardiography identified high PH probability in 54.4% of patients. RHC confirmed PH in 64 (71%) patients and ruled out PH in 26 (29%). Pulmonary artery diameter, transfer coefficient of the lung for carbon monoxide (KCO) and six-minute walking test distance (meters) were retained in the final model, with an AUC [95% CI] of 0.857 [0.779-0.935]. PH predicted risk was classified in low- (< 36%), intermediate- (≥ 36-<73%) or high-risk (≥ 73%) categories.
Conclusion:
A simple model based on three non-invasive objective variables obtained during the routine care of patients with fibrosing ILD showed good internal discrimination in our derivation cohort. Following external validation, the proposed nomogram could support PH-ILD suspicion and optimize echocardiography and RHC referrals.