Pulmonary arterial hypertension (PAH) is a rare disease, with an estimated prevalence of 48-55 cases per million adults and an annual incidence of 2.4-6.0 per million people.[4]Humbert M, Sitbon O, Guignabert C, et al. Treatment of pulmonary arterial hypertension: recent progress and a look to the future. Lancet Respir Med. 2023 Sep;11(9):804-19.
https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(23)00264-3/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/37591298?tool=bestpractice.com
[5]Leber L, Beaudet A, Muller A. Epidemiology of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: identification of the most accurate estimates from a systematic literature review. Pulm Circ. 2021 Jan-Mar;11(1):1-12.
https://onlinelibrary.wiley.com/doi/10.1177/2045894020977300
http://www.ncbi.nlm.nih.gov/pubmed/33456755?tool=bestpractice.com
Several registries have been established to collect data on baseline characteristics and outcomes of patients with PAH, with the first set up in the 1980s by the US National Institutes of Health.[6]Rich S, Dantzker DR, Ayres SM, et al. Primary pulmonary hypertension. A national prospective study. Ann Intern Med. 1987 Aug;107(2):216-23.
http://www.ncbi.nlm.nih.gov/pubmed/3605900?tool=bestpractice.com
Idiopathic pulmonary arterial hypertension (IPAH) is the most common type of PAH reported in the registries, accounting for 30% to 50% of cases.[7]Lau EMT, Giannoulatou E, Celermajer DS, et al. Epidemiology and treatment of pulmonary arterial hypertension. Nat Rev Cardiol. 2017 Oct;14(10):603-14.
http://www.ncbi.nlm.nih.gov/pubmed/28593996?tool=bestpractice.com
The age and sex distribution of the disease appears to have evolved over time. The mean age of patients in the first US registry was 36 years, with a female-to-male ratio of 1.7:1.[6]Rich S, Dantzker DR, Ayres SM, et al. Primary pulmonary hypertension. A national prospective study. Ann Intern Med. 1987 Aug;107(2):216-23.
http://www.ncbi.nlm.nih.gov/pubmed/3605900?tool=bestpractice.com
Contemporary registries from France and the US (REVEAL) later described a mean age at diagnosis of 50 years.[8]Humbert M, Sitbon O, Chaouat A, et al. Pulmonary arterial hypertension in France: results from a national registry. Am J Respir Crit Care Med. 2006 May 1;173(9):1023-30.
https://www.atsjournals.org/doi/full/10.1164/rccm.200510-1668OC#.UnPnTfnxobA
http://www.ncbi.nlm.nih.gov/pubmed/16456139?tool=bestpractice.com
[9]Badesch DB, Raskob GE, Elliott CG, et al. Pulmonary arterial hypertension: baseline characteristics from the REVEAL Registry. Chest. 2010 Feb;137(2):376-87.
http://www.ncbi.nlm.nih.gov/pubmed/19837821?tool=bestpractice.com
A significant proportion of patients (9% in the French registry) were older than 70 years.[8]Humbert M, Sitbon O, Chaouat A, et al. Pulmonary arterial hypertension in France: results from a national registry. Am J Respir Crit Care Med. 2006 May 1;173(9):1023-30.
https://www.atsjournals.org/doi/full/10.1164/rccm.200510-1668OC#.UnPnTfnxobA
http://www.ncbi.nlm.nih.gov/pubmed/16456139?tool=bestpractice.com
While the French registry confirmed a female-to-male ratio of 1.6:1, the US registry depicted a much higher female preponderance, with a female-to-male ratio of 3.9:1.[8]Humbert M, Sitbon O, Chaouat A, et al. Pulmonary arterial hypertension in France: results from a national registry. Am J Respir Crit Care Med. 2006 May 1;173(9):1023-30.
https://www.atsjournals.org/doi/full/10.1164/rccm.200510-1668OC#.UnPnTfnxobA
http://www.ncbi.nlm.nih.gov/pubmed/16456139?tool=bestpractice.com
[9]Badesch DB, Raskob GE, Elliott CG, et al. Pulmonary arterial hypertension: baseline characteristics from the REVEAL Registry. Chest. 2010 Feb;137(2):376-87.
http://www.ncbi.nlm.nih.gov/pubmed/19837821?tool=bestpractice.com
Another registry of six European countries found that the median age of IPAH diagnosis was 71 years and that younger patients had a female-to-male ratio of 2.3:1 while the female-to-male ratio in older adult patients was 1.2:1.[10]Hoeper MM, Huscher D, Ghofrani HA, et al. Elderly patients diagnosed with idiopathic pulmonary arterial hypertension: results from the COMPERA registry. Int J Cardiol. 2013 Sep 30;168(2):871-80.
http://www.ncbi.nlm.nih.gov/pubmed/23164592?tool=bestpractice.com
In the UK and Ireland, registry data from 2001 to 2009 showed an increase in the average age of IPAH diagnosis, from 45 to 52 years.[11]Ling Y, Johnson MK, Kiely DG, et al. Changing demographics, epidemiology, and survival of incident pulmonary arterial hypertension: results from the pulmonary hypertension registry of the United Kingdom and Ireland. Am J Respir Crit Care Med. 2012 Oct 15;186(8):790-6.
https://www.atsjournals.org/doi/10.1164/rccm.201203-0383OC
http://www.ncbi.nlm.nih.gov/pubmed/22798320?tool=bestpractice.com
Comorbidities including systemic hypertension, obesity, type 2 diabetes mellitus, and ischemic heart disease are common in patients with IPAH.
[Figure caption and citation for the preceding image starts]: Clinical classification and prevalence of pulmonary hypertension. CTEPH, chronic thromboembolic pulmonary hypertension; CpCPH, combined post- and pre-capillary pulmonary hypertension; IpcPH, isolated post-capillary pulmonary hypertension; mPAP, mean pulmonary arterial pressure; PH, pulmonary hypertension; PVR, pulmonary vascular resistance.Adapted from Eur Heart J, Volume 43, Issue 38, 7 October 2022, 3618–731; used with permission [Citation ends].