That is some stressful stuff.
My grandpa, who was nothing short of a 2nd dad to my brothers and I, died 3 years ago at age 71 after battling various complications from CAD that began when he was 58. If it weren't for the perma-damage he accumulated as a result of refusing to go to the hospital until 12-14 hours after his initial heart attack began at age 58, he'd probably still be alive today. I am bitter to this day about some of the circumstances of his passing...especially the fact that he died a couple weeks before my first daughter (and his first great grandchild) was born. I will be pissed until the day I die that he never met my children.
With that said, for what it's worth, I sincerely wish the best for your father and hope he has a speedy recovery. I hope there isn't any substantial perma-damage and hope he rebounds from this like a champ and that your family is able to spend another couple decades with him.