Pulmonary hypertension (PH) is a complex, progressing and debilitating disease associated with poor prognosis. Chronic thromboembolic pulmonary hypertension (CTEPH) — a distinct subtype of PH is the result of persisting pulmonary artery obstruction, most often caused by single or multiple episodes of pulmonary embolism (PE) and it is defined as elevated mean pulmonary arterial pressure (mPAP)≥25mmHg that persists more than six months after diagnosis of PE despite appropriate anticoagulation therapy [1].