If your flights are on 2 separate tickets and you miss your connecting flight AA will consider you a "no-show". That could present some problems.

While there is a good possibility AA will try to accommodate you on the "next" flight they have no obligation in that regard. Since you have separate tickets it is YOUR responsibility to get to the airport/flight on time and you DO NOT have the same rights for a missed connection as you would if your trip was booked on one ticket. If booked on one ticket, the responsibility for the missed connection and getting you to your final destination becomes AA's. with separate tickets the RESPONSIBILITY to get the connecting flight is ALL YOURS.

You could be charged a hefty "change fee" or worst case scenario (if you purchased a non-refundable ticket) you could be asked to pay for a new ticket. So think it through carefully BEFORE deciding to "take the gamble".