I assume that you are in touch with the doctor who will be treating your husband at the Cleveland Clinic? What does he or she say about the timing of the visit?
Where is it that doesn't have a lot of cases of covid? Not sure if Cleveland is surging right now, don't know. If you drive there and stay socially isolated, it's the best you can do because heart problems are also a concern. Covid isn't the only thing happening to folks.
I can see you're worried about the numbers of cases, but my state has less than half of Kentucky's cases and deaths, and I wouldn't be afraid to go to Ohio. Just do your social distancing, wear your masks, and wash your hands. Have some spray-on hand sanitizer in your purse. Things like that.
My experience of medical locations during the pandemic is that they are the most careful places of all. When we go to get my son's allergy shots (which have to be kept up on a certain schedule or they reduce the strength of the shot), we're met at the door of the building by a nurse who takes temps, hands out masks, and asks about symptoms. There aren't as many people around as there used to be, the air flow is appropriate, etc.
You could call the hotel where you're going to find out what measures they take to sanitize the rooms. You could bring some spray Lysol or something like that, too. I assume you're driving and not flying? You could even pack an ice chest with food so you don't have to stop so often.
Good luck with this decision, I assume it isn't easy. But heart problems seem to be more serious than the risk of exposure, especially since there are things you can do to alleviate the risk.