Adult-onset idiopathic peripheral pulmonary artery stenosis

Abstract

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.

Clinical characteristics of adult-onset idiopathic peripheral pulmonary artery stenosis (PPS). Overview of patient backgrounds, imaging findings, site of stenosis in pulmonary angiography, treatment profiles, treatment response and prognosis in this cohort study of patients with adult-onset idiopathic PPS. PAH: pulmonary arterial hypertension; TPA: transcatheter pulmonary angioplasty; mPAP: mean pulmonary arterial pressure; PVR: pulmonary vascular resistance; CI: cardiac index.

FIGURE 1

Comparative representative images of peripheral pulmonary artery stenosis (PPS) and chronic thromboembolic pulmonary hypertension (CTEPH). a, b) In a patient with PPS, a) lung perfusion scintigraphy showed multiple wedge-shaped defects and b) lung ventilation scintigraphy showed normal findings. c–e) Pulmonary angiography (PAG) from typical PPS cases presenting with c, d) multiple stenosis and e) tortuosity in segmental pulmonary arteries. f) Three-dimensional image constructed from PAG showed pulmonary arterial stenosis. g, h) PAG images g) before and h) after percutaneous pulmonary angioplasty. i–k) Optical coherence tomography showed thickening of the medial layer of the pulmonary artery and the vascular characteristics were different from those of CTEPH. These images were obtained in a few cases.

FIGURE 2

Location of pulmonary arterial stenosis and the numbers of patients within the spectrum of stenosis. We divided the pulmonary artery into four segments (pulmonary trunk, main pulmonary artery, segmental pulmonary artery and peripheral pulmonary artery) on pulmonary angiography and evaluated which site had stenosis. Patients with stenosis in the segmental and peripheral pulmonary arteries were the most common.

FIGURE 3

Kaplan–Meier curves of survival in patients with peripheral pulmonary artery stenosis (PPS): estimates of a) overall survival and b, c) outcome-free survival (b) all-cause death and hospitalisation due to right heart failure (RHF) and c) hospitalisation due to RHF). PPS was diagnosed on day 0. The dashed lines indicate 95% confidence intervals.

FIGURE 4

Clinical characteristics of adult-onset idiopathic peripheral pulmonary artery stenosis (PPS). Overview of patient backgrounds, imaging findings, site of stenosis in pulmonary angiography, treatment profiles, treatment response and prognosis in this cohort study of patients with adult-onset idiopathic PPS. PAH: pulmonary arterial hypertension; TPA: transcatheter pulmonary angioplasty; mPAP: mean pulmonary arterial pressure; PVR: pulmonary vascular resistance; CI: cardiac index.