[Pulmonary hypertension associated with congenital heart disease]

Congenital heart diseases are among the most common congenital malformations at birth with an incidence of 8/1,000 live births. These defects are characterized by a heterogeneous group of abnormal defects and connections between the cardiac chambers and vessels with different haemodynamic consequences and hence, varying need for follow-up and interventions. The most common forms are congenital cardiac shunts (i.e.: ventricular septal defects, atrial septal defects, patent ductus arteriosus) that account for almost 60% of the malformations.

Pulmonary hypertension remains a major complicating factor of many types of congenital heart disease characterized by a systemic to pulmonary shunt either by causing increased morbidity and mortality during or immediately after surgical repair, or even preventing complete repair for those with advanced pulmonary vascular disease. Similarities in histological lesions between congenital heart disease and idiopathic pulmonary arterial hypertension suggest similarities in pathobiological pathways and thus pulmonary arterial hypertension associated with congenital cardiac shunt has been classified in the group 1 of the classification of Venice. Even if these complex mechanisms are not completely elucidated, the role of hemodynamics (shear stress) in the development of pulmonary vascular disease has been clearly demonstrated.

Until recently, patients with advanced pulmonary vascular disease following congenital systemic to pulmonary shunt had no specific treatment and were managed empirically. Because of the similarities with idiopathic pulmonary arterial hypertension the use of novel therapies suggest new therapeutic possibilities for these patients. Randomized controlled trials are definitely needed to evaluate the safety and efficacy of these therapies in this very particular group of patients, both in the short and long term.