Chronic thromboembolic pulmonary hypertension: an update

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition characterized by single or recurrent pulmonary thromboemboli that obstruct the pulmonary vascular bed, promoting increased pulmonary vascular resistance and progressive pulmonary hypertension and right-heart failure. Some studies have analyzed the risk factors associated with CTEPH, e.g. prior pulmonary embolism, younger age, large perfusion defect, idiopathic pulmonary embolism at presentation, risk factors for venous thromboembolism. The symptoms and signs of pulmonary hypertension are extremely variable. Patients may complain of progressive dyspnea on exertion, hemoptysis and/or signs of right heart dysfunction including fatigue, palpitations, syncope or edema after a single episode or recurrent episodes of overt pulmonary embolism. Echocardiography is widely used as the initial diagnostic tool when pulmonary hypertension is suspected. Imaging technologies including ventilation-perfusion scanning, computed tomography, MRI, and pulmonary angiography are a fundamental part of the diagnostic workup of patients with suspected CTEPH. From the point of view of current treatment of CTEPH pulmonary endarterectomy surgery remains the treatment of choice for symptomatic patients. The most common reasons for rejection of patients referred for pulmonary endarterectomy are severe comorbidity and significant distal disease in combination with excessive pulmonary hypertension. Such patients may benefit from pre-operative reduction of pulmonary vascular resistance by means of medical therapy. In fact over the last decade, several novel therapies have been developed for pulmonary arterial hypertension, including prostacyclin analogs (epoprostenol, beraprost, iloprost), endothelin receptor antagonists (bosentan, sitaxsentan, ambrisentan) and phosphodiesterase-5 inhibitors (sildenafil)