it is possible that some patients in this series did not have PAH
classified by the criteria of the current guidelines.6
In the subgroup of patients with Down syndrome, who were all
treated with PAH-specific medications, we did not observe an
excess of mortality compared with the other patients.
The different survival observed among patients with PAH associated
with the different CHD clinical subgroups cannot be attributed
to a different treatment strategy. On the contrary, a larger
percentage of the patients with PAH with small or corrected
defects were treated with approved PAH-specific drugs compared
with the other two groups.