I believe Waffle Houses stay open all night. Unhealthy people are likely to go there in the wee hours since that is the only restaurant open. That can account for heart attacks in the vicinity of a Waffle House. Had the Waffle House not been there, the heart attacks would still happen.
I base this on a Waffle House that was close to my house. My husband was dying of cancer and I had registered nurses in my house 24 hrs. a day. When I couldn't sleep, I would go to that Waffle House, get eggs and coffee and read. I was not by myself in there; there were always people there. We should have all been sleeping but we were not for whatever reason.