It sounds like your husband suffers from coronary artery disease - does that term ring a bell? The coronary arteries become narrowed due to fatty deposits building up, and so the heart receives less blood (arteries bring blood to
the heart while veins pump blood out
of the heart). A heart attack results when an artery is completely blocked. It does sound like your husband has significant risk factors. I'm sure he knows that he has to change his lifestyle, but it sounds like he's in a stage of denial. Does he know how anxious this is making you? Do you have children that could help you talk to him?
I know how hard this can be. Remember that only he can change his own behavior; you just need to support him while he does it.