New Agents in the Treatment of Pulmonary Hypertension

Abstract

Pulmonary Hypertension (PH) is defined as an increase in mean pulmonary arterial pressure (PAP) ≥25 mmHg at rest as assessed by right heart catheterization (RHC). As stated in the European Society of Cardiology (ESC) 2009 guidelines, it can be classified into 5 main categories, presented in Table 1. Pulmonary arterial hypertension is a rare disease with a prevalence of 15 cases /million adult population and an incidence of 2.4 cases/million adult population/year. The pathophysiology of PH is complex and it has not been elucidated in detail since it involves various biochemical pathways and cell types. Vasoconstriction, remodeling with extensive proliferation of the vessel wall cells causing progressive obstruction, inflammation and thrombosis have been implicated. Structural or functional abnormalities of potassium channels in the smooth muscle cells and endothelial dysfunction characterized by impaired nitric oxide (NO) and prostacyclin production or increased expression of thromboxane A2 and endothelin-1are thought to underlie the cellular changes.

Although groups two and three account for the majority of the cases, the trials testing and validating therapeutic options involve mostly patients with group one PH (Pulmonary Arterial Hypertension-PAH). Apart from conventional therapy including diuretics, oral anticoagulants, calcium channel blockers in case of established vasoreactivity, digoxin, oxygen administration and exercise –rehabilitation programs, specific drugs have emerged and gradually find their place in the management of PAH during the last decade. Prostanoids such as intravenous (IV) epoprostenol, iloprost inhaled and IV and treprostinil subcutaneously (SC) or IV have been established agents in the management of PAH, improving performance ability and survival (epoprostenol)... (excerpt)