Characteristics in patients with adult-onset idiopathic peripheral pulmonary artery stenosis

Abstract

Abstract Background Peripheral pulmonary artery stenosis (PPS) refers to the obstruction of the pulmonary artery from the pulmonary artery trunk to the peripheral arteries. Although pediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Purpose To establish the disease profile of adult-onset PPS, we characterized the clinical background, laboratory and imaging findings, treatment, and prognosis. Methods The nationwide survey in Japan, supported by the government, retrospectively collected clinical data on patients with idiopathic PPS from multiple centers. This cohort comprised individuals aged 15 years and above who had pulmonary arterial stenosis confirmed through pulmonary angiography, indeed patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis were excluded. Patient backgrounds, imaging findings, treatment profiles, right heart catheterization findings, and long-term prognosis were collected. A comparison was made between the data obtained from prior-treatment and post-treatment right heart catheterization. Results Forty-five patients (median age at diagnosis: 38 years [Q1–Q3:28–56]; 29 males [64.4%]) with idiopathic PPS were enrolled from 21 centers. The median period between diagnosis of PPS and the final follow-up was 60 months [Q1–Q3: 24–114 months]. Eight patients (17.8%) were associated with moyamoya disease. Pulmonary angiography was performed in all patients for a definite diagnosis, and stenosis of segmental and peripheral pulmonary arteries was observed in 41 (91.1%) and 36 patients (80.0%), respectively. Thirty-six patients (80.0%) received treatment with pulmonary arterial hypertension (PAH)-specific drugs, 23 patients (51.1%) received combination therapy, and 25 patients (55.6%) received transcatheter pulmonary angioplasty. Right heart catheterization data showed improvements in both the mean pulmonary artery pressure (46 vs. 41 mmHg; p<0.001) and pulmonary vascular resistance (738 vs. 506 dyn.s.cm-5; p<0.001) from baseline to the final follow-up. The 3-, 5-, and 10-year survival rates of patients with idiopathic PPS were 97.6% (95% confidence interval [CI]:83.9–99.7), 89.7% [95% CI:69.9–96.6), and 68.6% (95% CI:43.9–84.2), respectively. Conclusion In this study, the 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 favorable treatment response to the PAH-specific drugs combined with transcatheter pulmonary angioplasty.