This isn't true. An admissible heuristic guarantees the optimal solution. With an inconsistent heuristic, A* can re-expand states multiple times, but will still end with an optimal path.
In other words, if the heuristic is consistent, then it implies that A* will expand the optimal number of states.
In other words, if the heuristic is consistent, then it implies that A* will expand the optimal number of states.