PAH is a rare, incurable, and progressive disease caused by an increase in pulmonary vascular resistance at the precapillary level.1-3 In a survey of national registries and expert centers in France and Scotland, the prevalence of all types of PAH was reported as being approximately 15 to 50 cases per million, with an incidence of idiopathic PAH of 6.5 to 25 cases per million. 2,4 There is a strong female preponderance and a higher rate of prevalence observed in high-risk groups, such as patients with systemic sclerosis.2 The estimated 1-year mortality rate ranges from 8% to 10% in patients with idiopathic, familial/heritable, or anorexigen-associated PAH. 5 An increase in mean pulmonary arterial pressure to at least 25 mm Hg at rest, together with a mean pulmonary capillary wedge pressure of <15 mm Hg, are the defining features of PAH.2 As PAH progresses, symptoms become exacerbated owing to restricted cardiac output through the pulmonary arteries and concomitant right heart failure, which induces common symptoms of PAH including breathlessness, fatigue, weakness, and angina.