There is not enough research into CHDs.
What's wrong, however, is the statement that this problem is too small for companies to invest research in. With 1 in 120 (approximately) kids born with heart defects, and a large percentage of those kids needing intervention, you can bet it's big enough to pay attention to.
The article does highlight, though, that there is hope in terms of new research. According to WSJ, the NIH is studying treatments in children with certain heart conditions and the American College of Cardiology is launching a catheter registry that aims to help inform doctors who treat kids. And at least one heart device for kids appears to be on the way: Medtronic’s experimental heart valve for both children and adults who had heart defects at birth.
Baby steps, but we can get there!