Evaluation of the Relationship between Chest Radiography Findings and Pulmonary Artery Pressure during Right Heart Catheterization

Background: Pulmonary artery hypertension is difficult to diagnose because of its nonspecific symptoms. Although echocardiography and more accurately catheterization can recognize pulmonary artery pressure, chest X-ray is widely used because of its availability. Objectives: This study was to evaluate the accuracy of chest radiography parameters for the estimation of pulmonary artery pressure. Methods: This cross-sectional study included 81 subjects with a definite diagnosis of pulmonary artery hypertension. Mean pulmonary artery pressure (mPAP) was determined by catheterization. Hilar enlargement, projection of the right heart border (PRHB), hilar enlargement + PRHB, and the ratio of these parameters to the thoracic diameter were compared to mPAP to evaluate correlations. Results: The average mPAP was 74.7±21 (ranging from 28 to 120 mmHg). Spearman’s test revealed that mPAP had a significant correlation with a hilar enlargement (r=0.489, P 0.001), hilar/thoracic ratio (r=0.482, P 0.001), hilar enlargement + PRHB (r= 0.517, P 0.001), and hilar + PRHB/thoracic ratio (r=463, P 0.001). Conclusion: Hilar enlargement and hilar/thoracic ratio on the chest radiography are proper parameters for the estimation of pulmonary artery pressure.