NPPB and pulmonary arterial hypertension: Prior studies and screening strategies have identified several predictors associated with PAH risk in CTD populations, including impaired gas transfer (reduced DLCO), elevated BNP/NT-proBNP reflecting cardiac strain, and echocardiographic features suggestive of increased pulmonary pressure and right-heart remodeling; these parameters are frequently combined in multimodal screening approaches rather than used in isolation [7,8,9,10].