Pulmonary hypertension (PH) is a chronic progressive condition characterized by an increase of mean pulmonary artery pressure above 25 mmHg at rest. Chronic thromboembolic pulmonary hypertension (CTEPH) is classified as a separate group (group IV), resulting from an incomplete resolution of pulmonary embolism (PE) and formation of chronic obstruction in the main pulmonary arteries [1]. The accepted criteria for the diagnosis of CTEPH is the presence of pre-capillary hypertension with at least one segmental perfusion defect on lung scan and typical findings on conventional pulmonary angiography or computed tomographic angiography after at least 3 months of anticoagulation [2].
