It could also be Esus, A being the 4th and B being the 5th of E. It probably depends on the context of the rest of the tune whether you're going to call it Asus2 or Esus - if it's resolving to either the A or the E then I'd call it the suspension of that chord.

You probably do have to specify it as a sus chord or use brackets to spell it out, ie (no 3rd) - otherwise anyone else reading it is likely to bung in the 3rd and lose the nice spacey quality of the chord.