It is kinda cool looking. But if people can see it in your chest you are doing it wrong.
My guess is that they put it in some kind of rubbery enclosure before installing it, but who knows? Maybe it's not actually a problem to have hard edges.
I don't see any untoward sharp edges. Though connecting the main blood pipes are would be an interesting trick to know about. No hose clamps there!
A colleague of mine required to have much metal put in his arm bones after an accident. He mentioned it always felt a bit heavy and cold. I can't imagine what this would feel like in your chest.