Can PDA in premature babies effect them in adult hood, even though it was treated?

Depends. The PDA is a structure we all had that permitted efficient heart pumping while we were not using our lungs. It occasionally doesn't close at birth (as expected) and adds to the pumping load. Closing it with meds or surgery is often done to help premi's grow. If it persists into childhood it can be closed electively. Once closed it is not a problem & unrelated to any heart problem i know of.
How? Was the PDA treated. If done interventionally (by catheter) there are no residual problems you need to expect. If done surgically there is a minimal risk for orthopedic issues ir reduced lung function related to the surgery.
Usually not. Once the PDA is treated and closed the patient will have no complication after that.