Specifically, metabolic syndrome can lead to arteriosclerosis, or "hardening of the arteries." This is when fats, cholesterol, and other substances stick to the sides of the arteries. The arteries then become clogged and brittle. Blood clots form when the arterial walls are damaged. If a blood clot forms, it can cause a heart attack or stroke.
Here are some sobering statistics from the American Heart Association and the American Diabetes Association: