my father is having another mid-life crisis

Work was dreadful this weekend, which I'm not going to get into because the whole thing is so ridiculous. One of the women I work with also works with my stepmother and she asked me how my dad was doing. I said I didn't really know because we haven't talked in a while. He didn't talk to me for 6 months, then he texted me for the phone number of my eye doctor and said he call me after he got an appointment. He never called back, so I left him a message he never returned, which was about 2 months ago. My coworker said that on Tuesday my stepmom was called into the office because my dad had a heart attack at work and she needed to go to the hospital. I was completely flabbergasted that I wouldn't even be told. We might not have a good relationship, but I thought we were on good enough terms. I called and talked to him for an hour or so after work. He said there was no heart damage and he had a stint put in. He also said that having a heart attack made him rethink his life and realize what's important. I keep thinking that this has happened before. He goes through something, realizes he's a dick, and tries to make it right, but it never works. I always end up being the only one trying. He's done this so many times that I don't know if I can do it again. In fact, he was supposed to call me Sunday, but it's Tuesday and he still hasn't.