Iloprost for chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTPH) is an uncommon complication of pulmonary embolism. The treatment of choice is thromboendarterectomy, a safe and effective surgical procedure in expert hands. However, a fair number of patients are not considered candidates for thromboendarterectomy or do not accept the risk involved. Such patients may respond well to prostacyclin or its derivatives. In recent years new vasodilator drugs administered by a variety of routes have appeared on the market. These drugs have been studied mainly for their effects on primary pulmonary hypertension or hypertension associated with connective-tissue diseases. Few trials have assessed their efficacy in patients with CTPH, however. We report 2 cases of CTPH in which thromboendarterectomy was rejected. Neither of the patients responded to the conventional treatment of anticoagulants, diuretics, calcium antagonists, and angiotensin-converting enzyme inhibitors, but they did respond very well clinically, hemodynamically, and functionally to an inhaled prostacyclin analog, iloprost. We discuss the effects of iloprost in patients with CTPH, its mechanism of action, and its use as a potential pharmacological alternative to thromboendarterectomy. We also discuss new pulmonary vasodilators in general.