The patients with PAHassociated with small defects were only 5% of
the overall PAH-CHD population of this study. They were the
youngest and had a predominance of post-tricuspid shunts
(60.0%). In these cases, the influence of the congenital defect in
the induction and progression of pulmonary vascular disease is
unclear and a diagnosis of idiopathic PAH with a concomitant congenital
defect may be proposed. The presence of a common underlying
cause for these two conditions has never been established.
Interestingly, the survival of patients with PAH associated with
small defects appears to be far better when compared with that of
‘classical’ idiopathic PAHpatients,17 In our study, the 15-year survival
was 66% for PAH associated with small defects and 38% for those
with idiopathic PAH. In contrast, the 15-year survival of the small
defects group was worse compared with the survival of patients
with Eisenmenger Syndrome (87%) and with systemic-to-pulmonary
shunts (86%).