Ok, I know it's not tatting, but tatting could be attached. The holes are there. - a whole bunch! A ring and chain edging would work. The rings don't need to be joined, because the stiffness of the heart form would keep 'em in place...er, that's the theory, anyhow. I've got a couple of polymer clay heart necklaces in my Flickr album.
They're old scans, so they're a little blurry.
I haven't forgotten about the beaded project for the class I'm preparing for the bead shop, just needed to take a little break from it! That's how I work - disorganized! (grin)