Sixty-four PTA patients in Beijing Chao-yang hospital (2011 to 2021) were included. According to National Institutes of Health criteria, 29 patients were in active stage and 35 were in inactive stage. Their medical records were collected and analyzed.

Compared with inactive group, patients in active group were younger. More patients in active stage presented fever (41.38% vs 5.71%), chest pain (55.17% vs 20%), increased C-reactive protein (2.91 vs 0.46 mg/L), erythrocyte sedimentation rate (35.0 vs 9 mm/h), and platelet count (291 vs 221 × 109/L). Pulmonary artery wall thickening was more common in active group (51.72% vs 11.43%). These parameters were restored after treatment. The incidence of pulmonary hypertension was comparable between groups (34.48% vs 51.43%), but patients in active group had lower pulmonary vascular resistance (PVR) (361.0 vs 891.0 dyn·s·cm−5) and higher cardiac index (2.76 ± 0.72 vs 2.01 ± 0.58 L/min/m2). On multivariate logistic regression analysis, chest pain [odds ratio (OR) 9.37, 95%CI (1.98–44.38), P = 0.005], increased platelet count (>242.5 × 109/L) [OR 9.03, 95%CI (2.10–38.87), P = 0.003] and pulmonary artery wall thickening [OR 7.08, 95%CI (1.44–34.89), P = 0.016] were independently associated with disease activity.

Chest pain, increased platelet count, and pulmonary artery wall thickening are potential new indicators of disease activity in PTA. Patients in active stage may have lower PVR and better right heart function.