A2, A7, A5, A10, or 89 hearts play the same way, and none of the above are "overwhelmingly strong" until the river hits. I think the only possible hand that you are ahead of given this action is 89o or 10x. To put the guy on 10x, however, I would want some sort of read like "bets into weakness" or "plays top pair very passively". The way you played it, and without further reads, I don't think he's bluffing enough on this river to merit a call.