Not anymore:

https://www.aa.com/i18n/customer-ser...ould%20expire.

"Just earn or redeem miles on American or with an AAdvantage® partner at least once every 24 months. We’ll automatically extend your mileage expiration date 24 months from the date of your most recent qualifying activity."

But apparently it's not even necessary to charge anything to an AAdvantage credit card anymore:

"Primary AAdvantage® credit cardmembers will not be subject to the 24-month qualifying activity period for as long as their card account is open." (Of course, I don't know how little card activity Citi will tolerate before it closes a credit card.)