Plasma PTX3 levels were higher in patients with CTEPH than in controls [5.51±4.53 ng/mL (range, 1.39 to 35.7) vs. 2.01±0.96 ng/mL (range, 1.06 to 4.84), p<0.0001]. Here, PTX3 is linked to chronic thromboembolic pulmonary hypertension.