Pathogenesis of Pulmonary Arterial Hypertension

The pathogenic mechanisms by which pulmonary arterial hypertension (PAH) develops and progresses are complex and not fully elucidated. Considerable heterogeneity in disease pathological features, some of which are unique and some common among the PAH spectrum of diseases, including idiopathic and scleroderma-associated PAH, adds further to this complexity. Our understanding so far has significantly progressed and has underpinned some of the successful therapeutics that are being used to treat PAH resulting in marked improvement in survival. In this revised chapter, we explore the biological processes and mechanistic insights that have advanced the field, the genetic and epigenetic components, the role of inflammation and metabolism, the cellular and molecular pathways, and their importance in the context of disease heterogeneity.