Pulmonary artery dilatation in different causes of pulmonary hypertension

Pulmonary artery (PA) dilatation is commonly observed in patients with pulmonary hypertension (PH). However, the clinical aspects of PA dilatation in various etiology of PH remain unknown. In this study, we investigated the clinical and imaging characteristics of 1018 patients with different subtypes of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). The independent determinants for all-cause death were identified using univariate and multivariate Cox proportional hazard models. PA dilatation was identified in 88.8% of the patients, and 27.2% had a PA diameter/ascending aorta diameter ratio greater than 1.5. PA diameter was shown to be significantly correlated with hemodynamic parameters and symptom duration in idiopathic PAH patients. PA diameter only correlated with pulmonary circulation volume in patients with PAH associated with congenital heart disease. PA diameter correlated with symptom duration and right ventricular end-diastolic dimension in CTEPH patients. PA diameter correlated with right ventricular end-diastolic dimension in patients with PAH associated with connective tissue disease. Only 6-min walk distance, but not PA dilatation, predicts all-cause death independently. In conclusion, PA dilatation is a common finding in PH patients. The clinical feature of PA dilatation varies greatly between PH types. PA dilatation is not associated with all-cause death.