The purpose of this study is to identify the clinical features, management pattern and long-term outcomes of patients with pulmonary arteries involvement in Takayasu's arteritis (TAK-PAI).

The present study intends to conduct a prospective analysis of the clinical data in TAK patients in order to:

1. describe the clinical characteristics and current status of multimodal treatment in patients with TAK-PAI, thereby enhancing the understanding of TAK-PAI;
2. to investigate the risk factors for mortality in patients with TAK-PAI, so as to promote early intervention and reduce mortality.
3. explore factors associated with pulmonary hypertention (PH) in patients with TAK-PAI, so as to facilitate the early identification of patients who may develop PH.

Inclusion Criteria:

• Hospitalized between Jan 1, 2016 and Dec 31, 2026
• Diagnosed with TAK according to the modified Ishikawa criteria and/or 1990 American College of Rheumatology criteria and/or 2022 ACR/EULAR criteria
• Diagnosed with pulmonary artery involvement using computed tomography pulmonary angiography or transcatheter pulmonary angiography
• Patients without aortic or primary branch involvement who nonetheless exhibited both clinical features and computed tomography-confirmed evidence of pulmonary artery involvement (PAI), after exclusion of other diseases causing pulmonary artery stenosis or occlusion

Exclusion Criteria:

• Patients with PAI caused by non-TAK diseases such as other types of vasculitis, fibrosing mediastinitis, pulmonary artery sarcoma, pulmonary sarcoidosis or chronic thromboembolic pulmonary hypertension

TAK patients hospitalized at the China-Japan Friendship Hospital, Beijing Anzhen Hospital and Beijing Chaoyang Hospital.