Abstract 12336: Non-invasive Screening for Pulmonary Hypertension in Idiopathic Pulmonary Fibrosis

Abstract

Introduction: Pulmonaryhypertension (PH) is a common complication of idiopathic pulmonary fibrosis (IPF) that is associated with poor prognosis. Screening for PH in IPF patients proves to be challenging. Hypothesis: We hypothesized that combining several non-invasive studies can predict the presence of PH in IPF patients. Methods: We included 235 IPF patients who underwent right heart catheterization (RHC) as part of the lung transplant evaluation. We measured ECG and echocardiographic variables as well as the pulmonary artery (PA) diameter and ascending aorta (AA) diameters on chest CT. We recorded results of arterial blood gases (ABG), pulmonary function (PFT) and 6-min walk tests (6MWT). Results: Several variables were predictors of PH in IPF patients in univariate models including arterial oxygenation, 6MWT distance, worse right ventricular (RV) function, the QRS axis, FVC/DLCOc ratio, PA/AA diameter ratio and estimated RV systolic pressure. In multivariate analysis, RV function and PA/AA ratio remained predictors of PH (c-statistics 0.75 (0.65-0.84), accuracy 71.4%). Similarly, RV function, PA/AA ratio and QRS axis were independent predictors of precapillary PH (c-statistics 0.86 (0.76-0.92), accuracy 84.2%). A combination of PA/AA diameter ratio <1.1, a QRS axis <90° and normal RV function showed a negative predictive value of 85% for precapillary PH. Conclusions: There are significant differences in ECG, echocardiographic, chest CT, PFT and ABG parameters between IPF patients with and without PH. However, these noninvasive tests alone or combination are not accurate enough for PH screening in IPF.