A marketing professional should have a methodology that he/she can bring anywhere: in that sense, you shouldn't have a problem. Of course a marketing professional who has cut his/her chops in the US market will have more to bring to the table; but instead of saying 'there's no way for me to get a job', you may have success if you're willing to accept for instance a lower pay; a lower position; or a less renowned company, while you 'learn'.
Visa issues are certainly there, though- but no more so than for any corporate/ general management-type jobs.