Changing demographics, epidemiology, and survival of incident pulmonary arterial hypertension: results from the pulmonary hypertension registry of the United Kingdom and Ireland.

Rationale: Incident pulmonary arterial hypertension was underrepresented in most pulmonary hypertension registries and may have a different disease profile to prevalent disease.Objectives: To determine the characteristics and outcome of a purely incident, treatment-naive cohort of idiopathic, heritable, and anorexigen-associated pulmonary arterial hypertension and to determine the changes in presentations and survival over the past decade in the United Kingdom and Ireland.Methods: All consecutive newly diagnosed patients from 2001 to 2009 were identified prospectively.Measurements and Main Results: A total of 482 patients (93% idiopathic, 5% heritable, and 2% anorexigen-associated pulmonary arterial hypertension) were diagnosed, giving rise to an estimated incidence of 1.1 cases per million per year and prevalence of 6.6 cases per million in 2009. Younger patients (age ≤ 50 yrs) had shorter duration of symptoms, fewer comorbidities, better functional and exercise capacity, higher percent diffusing capacit...