Lung neovascularity in pulmonary arterial hypertension associated with congenital heart defects and idiopathic pulmonary arterial hypertension: study of 198 patients.

OBJECTIVES: To correlate the severity of lung neovascularity (Sheehan vessels) with the cause and haemodynamic severity of pulmonary arterial hypertension (PAH), pulmonary artery (PA) size and heart disease type in patients with PH associated with congenital heart diseases (PAH-CHD) and idiopathic PH (IPAH).
METHODS: We reviewed the HRCT and CT pulmonary angiography studies of 87 patients with PAH-CHD and 111 with IPAH; all had undergone right heart catheterisation. We evaluated the PA size and severity of neovascularity on CT.
RESULTS: Neovascularity, which was found in 72% of PAH-CHD (56% with Eisenmenger's syndrome) and in 22% of IPAH patients, is significantly related to the severity of PH and all patients with severe neovascularity had intermediate or high PH. All PAH-CHD patients had a dilated PA with a greater risk of developing severe dilatation (diameter >5 cm). The neovascularity correlated with the PA size only in IPAH.
CONCLUSIONS: Neovascularity even if not pathognomonic for PAH-CHD, is significantly more common in these patients, especially in Eisenmenger's syndrome. It is often the first CT sign to indicate the severity of PH in PAH-CHD and IPAH. A neovascularity ≥5 on CT indicates a intermediate or high PH. KEY POINTS: • Large retrospective studying specific lung disorders in patients with pulmonary arterial hypertension. • Neovascularity is often the first CT sign indicating the severity of pulmonary hypertension Alterations of lung parenchyma on CT in pulmonary hypertension are described • The first study to assess the severity of pulmonary hypertension by CT • If substantiated, CT might eventually replace some cardiac catheterisation for evaluating PH.