Abstract
Idiopathic pulmonary arterial hypertension (IPAH), formerly called primary pulmonary
hypertension, is a rare disease (incidence and prevalence rates of approximately one
and six cases per million inhabitants, respectively) with different clinical phenotypes.
A group of diverse conditions manifest pulmonary arterial hypertension (PAH) and share
similar pathological and/or clinical findings with IPAH. By definition, IPAH is diagnosed
only after alternative diagnoses have been ruled out. Extensive investigation is needed
to determine if PAH is associated with thyroid diseases, infectious diseases, autoimmune
conditions, exposure to certain drugs (particularly anorexigens), certain genetic
mutations, and so on. The presence of genetic abnormalities and risk factors (such
as specific drug exposures) reinforces the “multiple hit” concept for the development
of pulmonary hypertension. Fortunately, within the past two decades, therapeutic options
have become available for IPAH, resulting in improved survival and clinical outcomes.
At least seven different compounds have been registered for PAH treatment. However,
even with aggressive PAH-specific therapy, mortality rates remain high (∼40% at 5
years). Given the high mortality rates, the use of combinations of agents that work
by different pathways has been advocated (either as “add-on” therapy or initial “up
front” therapy). Further, new therapeutic agents and treatment strategies are on the
near horizon, aiming to further improve survival from the remarkable progress already
seen.
Keywords
idiopathic pulmonary arterial hypertension - pulmonary arterial hypertension - heritable
PAH - epidemiology
