Pulmonary arterial hypertension associated with congenital heart disease

The functional and structural status of the pulmonary vascular bed plays a pivotal role in the presentation and outcome of the child with congenital and acquired cardiovascular disease. Pulmonary vascular disease secondary to congenital heart disease is classified as category 1 together with other causes of pulmonary hypertension that share similar histological and endothelial cell abnormalities. Our review suggests that both active vasoconstriction and pathological remodeling conspire to increase pulmonary vascular resistance. The combination of increased pulmonary blood flow and pulmonary artery pressure is a potent stimulator of pulmonary vascular disease. Permanent or progressive pathological changes seldom occur when malformations are corrected in the first 1–2 years of life. In privileged countries early diagnosis and prompt and accurate surgical repair have decreased the incidence of problematic pulmonary vascular disease considerably. It remains a major challenge to deliver such care globally to all infants with congenital heart disease. Patients with Eisenmenger syndrome were for a long time therapeutic orphans. However, the discovery of new orally available therapies have resulted in the inclusion of at least adult patients with Eisenmenger syndrome in randomized controlled trials of pulmonary vascular therapies. It is hoped that new insights into pulmonary vascular biology, improved understanding of genetic predisposition, development of therapies that engage novel pathways and improved delivery of medical and surgical care in underprivileged areas will substantially reduce the medical burden caused by pulmonary vascular disease associated with congenital heart disease.