Although Pulmonary arterial hypertension (PAH) is a rare disease, with an estimated prevalence of 15-50 cases per million,1 the prevalence of PAH in certain at-risk groups is substantially higher. For example, in HIV-infected patients the prevalence is 0.5%,2 in patients with systemic sclerosis it has been reported to be 7-12%,3,4 and in patients with sickle cell disease the prevalence is around 2-3.75%.5,6
Idiopathic PAH (IPAH) has an annual incidence of 1-2 cases per million people in the US and Europe and is 2-4 times as common in women as in men.7,8 The mean age at diagnosis is around 45 years, although the onset of symptoms can occur at any age.9 Despite the true relative prevalence of IPAH, heritable PAH (HPAH), and associated PAH (APAH) being unknown, it is likely that IPAH accounts for at least 40% of cases of PAH, with APAH accounting for the majority of the remaining cases.10
PAH associated with the newborn is known as persistent pulmonary hypertension of the newborn (PPHN) and arises when the normal decrease in pulmonary vascular tone does not occur after birth. Severe PPHN has been estimated to occur in 0.2% of live-born term infants, and some degree of pulmonary hypertension complicates the course of more than 10% of all neonates with respiratory failure.11
Due to the non-specific nature of the symptoms, PAH is unfortunately most frequently diagnosed when patients have reached an advanced stage of disease (WHO Functional Class III and IV).10
- Peacock AJ, Murphy NF, McMurray JJV, et al. An epidemiological study of pulmonary arterial hypertension. Eur Respir J 2007;30:104–9.
- Sitbon O, Lascoux-Combe C, Delfraissy JF, et al. Prevalence of HIV-related pulmonary arterial hypertension in the current antiretroviral therapy era. Am J Respir Crit Care Med 2008;177:108–13.
- Hachulla E, Gressin V, Guillevin L, et al. Early detection of pulmonary arterial hypertension in systemic sclerosis: a French nationwide prospective multicenter study. Arthritis Rheum 2005;52:3792–800.
- Mukerjee D, St George D, Coleiro B, et al. Prevalence and outcome in systemic sclerosis associated pulmonary arterial hypertension: application of a registry approach. Ann Rheum Dis 2003;62:1088–93.
- Machado RF, Gladwin MT. Pulmonary hypertension in hemolytic disorders: pulmonary vascular disease: the global perspective. Chest 2010;137:30S–38S.
- Fonseca GH, Souza R, Salemi VM, et al. Pulmonary hypertension diagnosed by right heart catheterization in sickle cell disease. Eur Respir J 2011 Sep 8. [Epub ahead of print].
- Gaine SP, Rubin LJ. Primary pulmonary hypertension. Lancet 1998;352:719–25.
- Badesch DB, Raskob GE, Elliott CG, et al. Pulmonary arterial hypertension: baseline characteristics from the REVEAL Registry. Chest 2010;137:376–87.
- Frost AE, Badesch DB, Barst RJ, et al. The changing picture of patients with pulmonary arterial hypertension in the United States: how REVEAL differs from historic and non-US Contemporary Registries. Chest 2011;139:128–137.
- 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;173:1023–30.
- Steinhorn RH. Neonatal pulmonary hypertension. Pediatr Crit Care Med 2010;11:S79–S84.