Confidence from experience: dual endothelin receptor antagonism in PAH

P ulmonary hypertension (PH) is classified into five logical treatment-based groups [1]. Pulmonary arterial hypertension (PAH) represents the first of these five groups and is further classified as idiopathic (predisposing factors having been excluded), familial or as occurring in association with certain conditions, including connective tissue disease, congenital heart disease and HIV infection. PAH is characterised by increased pulmonary vascular resistance as a consequence of vascular remodelling, which ultimately leads to right heart failure and death. Few effective medical therapies were available for PAH 10 yrs ago, and in many cases lung transplantation was the only viable treatment option. For patients with idiopathic PAH the outlook was bleak, with relentless deterioration and a predicted 5-yr survival of 22–38% [2]. Thanks to an explosion in research over the last 10 yrs, PAH has changed from an intractable, rapidly fatal condition to a serious but treatable disease.