GDF15 and pulmonary arterial hypertension: Therefore, in this study, RHC and IVUS were used to detect pulmonary hemodynamics and pulmonary vascular morphology, and ELISA was used to detect serum GDF-15 level to investigate the correlation between serum GDF-15 and pulmonary hemodynamics and pulmonary vascular morphological changes in patients with pulmonary hypertension.