Fig. 2

Overview of the pathogenesis of PAH: triggers and cellular and biological alterations. PAH is characterized by the thickening of the pulmonary artery walls and a decrease in lumen size, leading to increased pulmonary vascular resistance and right ventricular failure. Triggers include genetic/epigenetic alterations, inflammation, infections, hypoxia, and drugs/toxins, which promote a pro-inflammatory and prothrombotic phenotype in PAEC, PASMC, and fibroblasts. This leads to vasoconstriction, cell proliferation/migration, and the inhibition of apoptosis. Media thickening also contributes to vessel narrowing. Late-stage PAH is often accompanied by decompensated RV failure, associated with capillary rarefaction, metabolic changes, oxidative stress, inflammation, fibrosis, and neurohormonal activation. LV left ventricle, PAH pulmonary arterial hypertension, RV right ventricle. Created with BioRender.com