Learning from registries in pulmonary arterial hypertension: pitfalls and recommendations

Abstract

Pulmonary arterial hypertension is a rare and incurable chronic disease characterised by a progressive increase in pulmonary vascular resistance and right heart failure. Patient registries collecting observational data can be of great value in the understanding of clinical problems. While clinical trials provide data in selected patient populations, registries better depict real-life practice. This review aims to reflect the input of patient registries in the general knowledge of the disease. Advances in epidemiology of the different subgroups, including data on incidence and/or prevalence, increasing age at presentation and stagnating diagnostic delay are reported. The importance of haemodynamic definition criteria and cardiac comorbidities are underscored. The review also shows the major transformation that pulmonary arterial hypertension therapeutic management has undergone, with still insufficient use of combination therapies; consecutive improvement in outcome; upcoming evidence in disfavour of anticoagulation; and validity of the available risk-stratification tools derived from large registries. Product registries are also briefly presented. Finally, the benefits of registries and methodological aspects are discussed, including immortal time bias, registry data quality and recommendations from EU organisations (EUCERD and PARENT).

FIGURE 1

Timeline of pulmonary arterial hypertension (PAH) registries and their characteristics (list is not exhaustive). Darker circles indicate product registries as opposed to disease registries. PPH: primary pulmonary hypertension; NIH: National Institutes of Health; PHC: Pulmonary Hypertension Connection; IPAH: idiopathic PAH; IPPHS: International Primary Pulmonary Hypertension Study group; TRAX: Tracleer Excellence Post Marketing Surveillance Programme; SPAHR: Swedish Pulmonary Arterial Hypertension Registry; REVEAL: Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension; ASPIRE: Assessing the Spectrum of Pulmonary Hypertension Identified at a Referral Centre; PH: pulmonary hypertension; COMPERA: Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension; VOLT: the Volibris Tracking Study; EXPERT: Exposure Registry Riociguat in Patients with Pulmonary Hypertension. *: same mean age in IPAH patients.

FIGURE 2

Pulmonary arterial hypertension (PAH) survival rates by subtypes and selected registries. US-NIH: United States National Institute of Health [7]; US-PHC: United States Pulmonary Hypertension Connection [48]; US-REVEAL: United States Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension [9, 49]; COMPERA: Comparative, Prospective Registry of New Initiated Therapies for Pulmonary Hypertension [12]; Spanish registry [11]; UK registry [50]; Swedish registry [5].