Pulmonary artery size as a predictor of outcomes in idiopathic pulmonary fibrosis.

ABSTRACT

UNLABELLED IPF patients have heightened propensity for pulmonary hypertension, which portends a worse outcome. Presence of pulmonary hypertension may be reflected in an enlarged pulmonary artery. We investigated pulmonary artery size measured on high-resolution computed tomography (HRCT) as an outcome predictor in IPF.We retrospectively reviewed all IPF patients evaluated at a tertiary-care centre between 2008 and 2013. Pulmonary artery and ascending aorta diameters were measured from chest HRCT with pulmonary arteryascending aorta diameter (PAA) ratio calculations. Outcome analysis defined by either death or lung transplant based on pulmonary artery size and PAA ratio over 60 months was performed. Independent effects of different variables on overall outcomes were evaluated using the Cox proportional hazards model.98 IPF patients with available HRCT scans had a mean pulmonary artery diameter and PAA ratio of 32.8 mm and 0.94, respectively. Patients with a PAA ratio >1 had higher risk of death or transplant compared with a PAA ratio ≤1 (p<0.001). A PAA ratio >1 was also an independent predictor of outcomes in unadjusted and adjusted outcomes analyses (hazard ratio 3.99, p<0.001 and hazard ratio 3.35, p=0.002, respectively).A PAA ratio >1 is associated with worse outcomes in patients with IPF. HRCT PA A ratio measurement may assist in risk stratification and prognostication of IPF patients.