Heart attacks honestly are not as scary in terms of bodybuilding as is heart failure. Heart failure means the excess weight is causing the heart to work harder and this can lead to edema, blood clotting, and eventual stroke or sudden cardiac arrest(not a heart attack). It often does this through causing an arrhythmia, which also can lead to clotting and stroke. This is where a sudden death can occur.
A heart attack usually comes from atherosclerosis, a buildup of plaque which doesn't happen overnight. It usually takes years of coronary arteries becoming narrower and narrower from bad cholesterol,etc. Kali Muscle had near 100% blockage of his arteries. So did McCarver. This is preventable through some basic medical tests(angiogram, blood tests, stress test,etc). Unless completely genetic, these heart attacks can be prevented. But once you have a heart attack, there is severe damage done to the heart and now you are looking at heart failure, basically a weak heart. This causes clotting issues, strokes, and sudden cardiac arrest like Meadows. That's the instant death out of nowhere stuff and at that point not much you can do. These guys are not monitoring their health as they claim they are.
It's now sheik to claim that "throughout my whole career I always got bloodwork and got a physical exam at least 2-3 times a year". Bullshit. If a halfway decent doctor saw really bad cholesterol numbers, bad calcium channel scores, etc., he would probably order some heart tests to see if there was coronary blockage. Same with kidneys. Basic check of not only creatinine but urea nitrogen, etc. and you'll know you're kidneys are at risk. Not these stories that "out of nowhere" you just had multiple organ failure.
So guys in their 40's and 50's with super bad cholesterol numbers weighing 300lbs, doing "dirty bulks" and not checking basic health parameters having heart attacks is really not that surprising. It certainly is preventable though. The likely culprit for heart attacks in bodybuilders, as boring as it sounds, is probably diet. Matarazzo talked about how he had LBS. of red meat per day to bulk. Piana and his Ben and Jerry's nightly. Given that anabolic steroids are known to make cholesterol values worse, the combination of horrible diet and ALOT of that type of food for years, with the contributing factor of steroids really makes perfect sense for heart attacks in bodybuilders. Same with high blood pressure and kidney failure.
Heart failure is a whole different story.