lets recap how insulin messes with your circulatory system....this is from leirre keith's "The Vegetarian Myth"
too much insulin triggers growth of the smooth muscle lining of the arteries, causing them to thicken, becoming less elastic. less blood can get threw the arteries at one time, but there is still the same amount of blood trying to get around your body, this causes more pressure..aka high blood pressure. on top of that, now the kidneys are retaining more fluid, more fluid more pressure. even higher blood pressure. Insulin also encourages connective tissue growth on the inside of the arteries, which has a roughish fiberous texture, so more plaque has something to stick to.
so if you have plaque build up, and your arteries are less elastic, well you are headed for a something scary. it doesn't matter how high your percent of plaque is when it comes to an attack, all that matters is one plaque burst or whatever the heck it really does in there. This is one reason cardio can be beneficial. not only will it help with insulin levels, but especially if you are doing interval cardio, like kettle bells, your vessels have to learn not to expand and contract depending on your heart beat. this keeps them more able to be flexible / elastic, so the plaque also learns from this, and gets less like a stuck couch potato. it's as if you took a ballon, and put some mud on it. if it sat there and dried it would be more likely to crumble, but if you kept that ballon inflated and deflated, it would be harder for it to get all stuck in one spot.