[Medical treatment in patients with chronic thromboembolic pulmonary hypertension]

Pulmonary thromboendarterectomy is the treatment of choice in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, specific medical treatment of pulmonary hypertension (PH) can be an alternative or play a complementary role to surgery. Thus, in patients unsuitable for surgery due to distal thrombotic obstruction, residual or persistent PH after surgery or very severe PH and a high-risk hemodynamic profile, medical treatment may improve their clinical course and the outcome of thromboendarterectomy. Patients with distal obstruction in the pulmonary tree and those with residual PH after surgery show clinical and hemodynamic deterioration due to progression of the pulmonary vascular disease in the smallcaliber arterioles. Conventional treatment with diuretics, anticoagulants and oxygen therapy has been demonstrated to have little effectiveness. In the last decade, numerous drugs have been developed for the treatment of PH: prostacyclin analogs, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors acting principally in vascular remodelling of small-caliber arterioles. Although evidence of the effectiveness of these drugs in PH and the histological similarity of small-vessel vasculopathy in CTEPH to that of other forms of PH provide the main rationale for the use of these drugs in patients with CTEPH, the evidence from clinical trials is still limited.