NPPB and pulmonary arterial hypertension: Among the baseline variables in patients with PAH, the 6MWD, WHO-FC, CRP, platelet count, and LCR showed statistical differences between the two groups with and without clinical worsening events, while other variables (including age, female, height, weight, BMI, PAH subtype, initial therapy, seven variables in RHC, four variables in echocardiography, WBC, lymphocyte, monocyte, platelet, and BNP) did not show statistical differences.