Predictive value of chest HRCT for survival in idiopathic pulmonary arterial hypertension

Little attention has been paid to chest high resolution computed tomography (HRCT) findings in idiopathic pulmonary arterial hypertension (IPAH) patients so far, while a couple of small studies suggested that presence of centrilobular ground-glass opacifications (GGO) on lung scans could have a significant negative prognostic value. Therefore, the aims of the present study were: to assess frequency and clinical significance of GGO in IPAH, and to verify if it carries an add-on prognostic value in reference to multidimensional risk assessment tool recommended by the 2015 European pulmonary hypertension guidelines.

Chest HRCT scans of 110 IPAH patients were retrospectively analysed. Patients were divided into three groups: with panlobular (p)GGO, centrilobular (c)GGO, and normal lung pattern. Association of different GGO patterns with demographic, functional, haemodynamic, and biochemical parameters was tested. Survival analysis was also performed.

GGO were found in 46% of the IPAH patients: pGGO in 24% and cGGO in 22%. Independent predictors of pGGO were: positive history of haemoptysis, higher number of low-risk factors, and lower cardiac output. Independent predictors of cGGO were: positive history of haemoptysis, younger age, higher right atrial pressure, and higher mixed venous blood oxygen saturation. CGGO had a negative prognostic value for outcome in a 2-year perspective. This effect was not seen in the longer term, probably due to short survival of cGGO patients.

Lung HRCT carries a significant independent prognostic information in IPAH, and in patients with cGGO present on the scans an early referral to lung transplantation centres should be considered.