From acute pulmonary embolism to chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH), a disease associated with considerable morbidity and mortality, is the consequence of unresolved thromboembolic occlusion in pulmonary vasculature. CTEPH was considered a rare disease occurring in 0.1-0.5% of patients with pulmonary emboli who survive. Recently, a much higher incidence was reported and some risk factors such as a previous pulmonary embolism (PE), an idiopathic form of PE and the severity of perfusion defect at the time of diagnosis have been identified. Exertional dyspnea is the main symptom at the beginning of the disease while later on patients may suffer from syncope related to low cardiac output or hemoptysis as a consequence of high pulmonary artery pressure. In suspected patients, a confirmation of pulmonary arterial hypertension should be ascertained at transthoracic echocardiography. Then the obstructive nature of the disease may be revealed by ventilation-perfusion lung scan but is better described at pulmonary angiography. Computed tomography scan may be useful to rule out confounding disorders. To prevent recurrences, long-term oral anticoagulants to maintain an INR between 2.5 and 3.5 (target 3.0) are indicated. Treatment of severe CTEPH is essentially surgical (thromboendarterectomy). This procedure may be difficult when distal branches of pulmonary vascular tree are involved. In selected cases, alternative therapies may be the arterial pulmonary vessel angioplasty and lung transplantation.