After making the initial cut based on academics, I think most schools will use your other endeavors (school-elected position, volunteer activities, contributions to the student body etc) in the final selection process. I think only junior AOA is solely based on academics.
If you're at the top of your class academically, then start doing other stuff that will get you some face recognition by the administration. There are tons of stuff to do in med school. Find what interests you the most.