This study assessed dynamics of PAPP-A in CTEPH patients who undergo therapy with pulmonary endarterectomy (PEA) or balloon pulmonary angioplasty (BPA).<h4>Methods</h4>The study included a total of 125 CTEPH patients scheduled for treatment (55 PEA/ 70 BPA) and a control group of 58 patients with pulmonary hypertension other than CTEPH. This evidence concerns the gene PAPPA and pulmonary hypertension.