A change of mind implies that there is an opportunity for changing one's mind.  When one takes a vow in the presence of God until death, there is no change of mind, unless one changes one's belief in God, as well.  And if that's the case, then communion doesn't count anymore.  

That said, if one does change his mind, the recourse is to try and change it back or find a way to live as a married couple in spite of it.  Things get better, things get worse, we get rich, we get poor, we get sick....things change.  Marriage is a big gamble for those who have expectations of lifelong happiness and bliss.