ABSTRACT
The endothelin (ET) system has been of recognized importance in cardiac and pulmonary vascular disease for many years (1,2). The development of the endothelin receptor antagonists (ERAs) as a therapeutic modality in pulmonary arterial hypertension (PAH) represents an important milestone in the treatment of this deadly disease. These medications were the first orally available agents specific for PAH treatment, providing therapeutic options for those patients unresponsive to calcium channel blockers and either not ready or ineligible for intravenous prostanoid therapy. The use of ERAs ushered in a new era of PAH therapeutics, which continues to evolve today.
