PAH-Associated Congenital Heart Disease: Finding Common Ground With Primary Pulmonary Hypertension

As we planned this issue on pulmonary arterial hypertension (PAH) in congenital heart disease and in children, we sensed the long shadows of physicians who have helped establish the parameters of its diagnosis. There were giants like Viktor Eisenmenger, who described the clinical features of a patient with PAH more than 100 years ago, and Paul Wood, who subsequently used the term “Eisenmenger syndrome” to describe PAH with reversal of a systemic to pulmonary shunt. As the nomenclature has evolved so has our understanding of the conditions seen in association with pulmonary hypertension.A reclassification by the World Health Organization in 1998 brought us further along, as it emphasized similarities between primary pulmonary hypertension and PAH of certain known etiologies. An improved understanding of the mechanisms underlying the vascular changes in PAH has been an important factor in the emergence of new therapies. Notably, some medical therapies for the treatment of primary pulmonary hypertension may benefit patients with PAH associated with congenital heart disease. It is intriguing to find the diversity in the etiology of PAH and yet some uniformity in treatment approaches.Our Roundtable Discussion so capably managed by Robyn Barst, MD, explored all of these issues. We have all recognized how difficult it may be to differentiate whether a patient with a congenital heart defect has Eisenmenger syndrome as opposed to primary pulmonary hypertension. The experts in pediatric cardiology we brought together for the Roundtable, as well as the authors of our articles in this issue, addressed this and many other difficult questions and present a comprehensive discussion of vital topics essential to our understanding of PAH in congenital heart disease. Hopefully, the insights presented will give us a clearer perspective on how to classify and treat patients who have these diseases.