Clinical case of combination therapy including ambrizentan in the patient with severe idiopathic pulmonary arterial hypertension

Idiopathic pulmonary hypertension (IPAH) is a rare cardiovascular disease of unknown etiology, but the most common form of pulmonary arterial hypertension, defined as mean pulmonary arterial pressure >25 mmHg and pulmonary vascular resistance >3 Wood Units. Endothelial dysfunction seems to play an integral role in the pathogenesis of IPAH: the activation of endothelin-1 causes the hypertrophy of smooth muscle cells and endothelial cells, fibrotic changes, immune inflammation and vasoconstriction which leads to small pulmonary arteries and arterioles remodeling. The endothelial system activation is the reason for using endothelin receptor antagonists (ERA) to block the endothelin receptors type A (ETA) or both types (ETA, ETB). ERA, as the main class of PAH-specific therapy, is presented by bosentan and macitentan, dual endothelin receptor antagonists, and ambrisentan, non-sulfonamide, ETA-selective ERA. This clinical case demonstrates the successful treatment with ambrisentan as the part of combination therapy in the patient with severe IPAH.