If the valve can be repaired by surgery using non artificial parts, you'll get your class 1 back. My old (and he'll hate being called that) had a class 1, lost it due his ticker (heart valve problem), had the surgery and his ticker was not only found, but repaired.
He got his class 1 medical back.
If your condition can be repaired, then there's no reason why you shouldn't get a class 1.
You'll have to get specialist medical advice on this one.