Adult-onset idiopathic peripheral pulmonary artery stenosis.

BACKGROUND: Peripheral pulmonary artery stenosis (PPS) refers to stenosis of the pulmonary artery from the trunk to the peripheral arteries. Although paediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Our objectives in this study were to characterise the disease profile of adult-onset PPS. METHODS: We collected data in Japanese centres. This cohort included patients who underwent pulmonary angiography (PAG) and excluded patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis. Patient backgrounds, right heart catheterisation (RHC) findings, imaging findings and treatment profiles were collected. RESULTS: 44 patients (median (interquartile range) age 39 (29-57) years; 29 females (65.9%)) with PPS were enrolled from 20 centres. In PAG, stenosis of segmental and peripheral pulmonary arteries was observed in 41 (93.2%) and 36 patients (81.8%), respectively. 35 patients (79.5%) received medications approved for pulmonary arterial hypertension (PAH) and 22 patients (50.0%) received combination therapy. 25 patients (56.8%) underwent transcatheter pulmonary angioplasty. RHC data showed improvements in both mean pulmonary arterial pressure (44 versus 40 mmHg; p<0.001) and pulmonary vascular resistance (760 versus 514 dyn·s·cm-5; p<0.001) from baseline to final follow-up. The 3-, 5- and 10-year survival rates of patients with PPS were 97.5% (95% CI 83.5-99.6%), 89.0% (95% CI 68.9-96.4%) and 67.0% (95% CI 41.4-83.3%), respectively. CONCLUSIONS: In this study, patients with adult-onset idiopathic PPS presented with segmental and peripheral pulmonary artery stenosis. Although patients had severe pulmonary hypertension at baseline, they showed a favourable treatment response to PAH drugs combined with transcatheter pulmonary angioplasty.