The first Keystone Symposia Conference on pulmonary vascular isease and right ventricular dysfunction: Current concepts and future therapies

Pulmonary arterial hypertension (PAH) is characterized by progressive obliteration of pulmonary arterioles leading to increased pulmonary vascular resistance, right heart failure, and death in 30-60% of PAH patients five years after diagnosis. Although PAH is primarily a vascular disease, patients die from right ventricular failure. PAH is a panvasculopathy with key abnormalities evident in the blood, endothelium, smooth muscle cells, and fibroblasts. While the pathology in PAH is mainly evident in the resistance arteries, there are also abnormalities in the large pulmonary arteries and in the right ventricular microcirculation that accompany the syndrome. There is a component of vasoconstriction in many PAH patients; however, recent research suggests a substantial role for excessive proliferation, migration, and resistance to apoptosis of vascular cells. It is also evident that PAH is characterized by proliferative-inflammatory responses mediated by blood and fat cells as well as lymphoid tissue within the lung.