I am coming from a non-medical profession and only had 8 hours of shadowing and no medical experience, but I got accepted into Emory early-admissions for next year. I don't know about other programs, but Emory seems to be most interested in strong students that they can mold into excellent AAs. Emory told me that they have found that those with the least medical experience are often the best students because they already know that they have the most to learn. If your GPA, GRE and references are strong, then I think the hours of shadowing you have already done should be enough. Just be sure you are very knowledgeable about the AA field and know for certain that you want to do this. Good luck!