Lessons from pulmonary hypertension registries

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are major causes of pulmonary hypertension (PH) that have benefited from novel medical, interventional and surgical strategies in the last two decades.1---3 Patient registries have provided important information on the clinical characteristics and natural history of different forms of PH. 4,5 Since the US National Institutes of Health (NIH) registry conducted in the 1980s, subsequent registries and databases have yielded additional information on the demographic factors, treatment, and survival of patients with different forms of PH, including PAH and CTEPH.6---9 These registries have enabled comparisons between populations in different eras and environments.10,11 In addition, the NIH and French registries have developed equations to predict one-, twoand three-year survival of patients with idiopathic, heritable, and drug-induced PAH.12---15 These equations have been widely used as comparators in subsequent studies, in order to present indirect evidence of improved outcomes.4 Since then, the US Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL)