Li X, Zhang C, Sun X, et al. - Researchers examined the link between the dilatation of pulmonary artery and prognosis of connective tissue disease (CTD)-associated pulmonary arterial hypertension (PAH)(CTD-PAH) patients. Overall 140 CTD-PAH patients diagnosed via echocardiography from 2009 to 2018 were retrospectively analyzed. All patients underwent a chest multi-slice CT. Age, gender, main pulmonary artery (MPA) diameter, left pulmonary artery diameter and right pulmonary artery diameter were found to be associated with the risk of 5-year all-cause mortality among patients with CTD-PAH, as revealed in Cox univariate proportional hazard analysis. In Kaplan–Meier analysis, it was demonstrated that patients with MPA ≥ 37.70 mm vs MPA ≤ 37.70 mm had a significantly lower 5-year survival rate. Overall, in Chinese CTD-PAH patients, MPA diameter ≥ 37.70 mm recorded by chest multi-slice CT was identified as a potential independent risk factor of the poor long-term prognosis.