Is oral sex okay a day after a pfo closure attempt?

Probably: Was the pfo closed? You do not attemp to close a pfo, you either do or don't. Is there a device implanted. As long as there good hygiene and no cuts in the mouth that can result in bacteremia given no foreign body, if good oral hygiene maintained, no major concerns.

Yes: There shouldn't be any problems. If they accessed the veins in the groin area (femoral), just be careful not to bend your legs excessively for ~48 hrs post procedure. Always good to check with your cath doc though.