Epidemiology of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: identification of the most accurate estimates from a systematic literature review

This systematic review of literature and online reports critically appraised incidence and prevalence estimates of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension to identify the most accurate estimates. Medline (R) and Embase (R) databases were searched for articles published between 1 January 2003 and 31 August 2020. Studies were grouped according to whether they were registries (population-based estimates), clinical databases (hospital-based estimates) or claims/administrative databases. Registries were classified into systematic and non-systematic registries, according to whether every national centre participated. Of 7309 publications identified, 5414 were screened after removal of duplicates and 33 were included. Inclusion was based on study type, availability of a clear numerator (diagnosed population) and a population- or hospital-based denominator, or all primary data required to calculate estimates. Only the most recent publication from a database was included. Most studies were based on European data and very few included children. In adults, the range of estimates per million was approximately 20-fold for pulmonary arterial hypertension incidence (1.5-32) and prevalence (12.4-268) and of similar magnitude for chronic thromboembolic pulmonary hypertension incidence (0.9-39) and prevalence (14.5-144). Recent (<= 5 years) national systematic registry data from centralised healthcare systems provided the following ranges in adult estimates per million: approximately 5.8 for pulmonary arterial hypertension incidence, 47.6-54.7 for pulmonary arterial hypertension prevalence, 3.1-6.0 for chronic thromboembolic pulmonary hypertension incidence and 25.8-38.4 for chronic thromboembolic pulmonary hypertension prevalence. These estimates were considered the most reliable and consistent for the scientific community to plan for resource allocation and improve detection rates.