Not so sure even slam try is so good idea. Give partner Axx, AKxx, xx, Axxx and you are in 5 spades with around 70% chance. Qxx, Axxx, Axx, Axx and you are in bad slam and even AQx, Axxx, xxx, Axx is not cold.
If West plays 9 from 9x you are down.
Assuming perfect defense you have:
59.75% 3 heart tricks
20.87% 50% chance from elimination
19.38% no chance
If hearts are 5/1 you can play A spade and a spade for a 50% chance.
Not a bad plan :)