～ことに

A noun, adjective, or verb + ことに can be used to express the speaker's feelings about what is said in the next part of the sentence. It's limited to a certain set of words and is translated as something like "it is X that..." as in "it is sad that..." or "I am X that..." as in "I am happy that..." A couple verb examples from Tobira are 驚いたことに (to one's surprise) and 腹の立つことに (what makes me angry is that...)

悲しいことに、大学を卒業してから、大学時代の友達と会えなくなってしまった。
I'm sad that once I graduate university, I won't be able to see any of my university friends anymore.

嬉しいことに、シュウは学校のあとに家にくるって言ってた。
I'm happy that Shuu said he'll come over to my house after school.

残念なことに、私達のチームは最後の試合で負けてしまった。
To my regret, our team lost at the end of the match.

驚いたことに、カナトはお菓子を食べないで寝るんだよ。
To my surprise, Kanato went to bed without eating any sweets.