My question is if jutsu can still be used and if he can heal. And having a pierced heart is way different than having it removed altogether. 9-tails not entirely mastered, of the seal breaks then he no longer has that to use, and if he doesn't surrender after all that, to be able to come back and in some form finish him off should not be the chore.
If he still has a nervous system, he will still be able to move around for a time. As to whether he'll still be able to perform jutsu - his ability to do so will be severely diminished because as Shadow noted, the heart holds a large portion of the person's chakra. Depending on how the fight has gone thus far (I haven't been following), Athos may or may not have already used a significant portion of his chakra. If he has, then he'll be even worse off.
In the second Naruto Fanbook, Kishimoto stated that one thing that could kill Hidan was malnutrition. Well, using a little SCIENCE! we can see that without a heart, Athos will eventually lose the fight. Why? Cellular respiration.
Without a heart pumping blood through Athos' body, there's no way to transport oxygen to different parts of his body. The blood is just going to pool in his extremities. No blood circulation means no diffusion of new oxygen molecules across cell membranes throughout his body. No new oxygen molecules means no production of ATP (the "energy" source that the body uses for everything). No ATP means no movement, no speaking, no production of chakra, nothing.
In the case of malnutrition and starvation: The two things you need to produce ATP (technically there's more things you need, but they're intermediate products in the entire cellular respiration process that are produced from oxygen and glucose) are glucose (the carbohydrate we get from foods) and oxygen. No glucose, you still can't produce ATP.
This is a grossly simplified explanation, but it serves its purpose. SCIENCE, BITCH!