Ask your Dad if he enjoys living. Without the bypass his chances of living a longer life will diminish. I'm not a Dr. but I have had heart attacks and currently have 5 stints. When they put in the last 2 they wanted to do a bypass and I was bull headed and told them no unless it was the only way of keeping me alive. Today several years later I find myself having a hard time breathing that is getting enough air to do the normal things I enjoy. Now on medicare its harder to get things done than it was when I payed for Blue Cross and Blue Shield before I retired.