As the opening bid is Reverse then the Opening hand may be 18-19 or 18-21 and there may be 5 clubs 4 diamonds 3 spades 1 heart or 2spades 2 hearts as the 3 spades shall be 3 spades here. So to play in 8 card trump fit in 4 spades shall be better. The 3 NT will be dangerous in Heart suit. I do not try in Slam here as there is lack of 33 HCP .