It’s not about the blockage. It’s how much plaque you have in your arteries.
The first question most people ask when told they have Coronary Artery Disease is “How much of a blockage do I have in my arteries?” Most of us think an 80% blockage is more dangerous than a 30% blockage. In fact, the newest research shows this is not necessarily true.
The vast majority of heart attacks happen in arteries that are less than 50% blocked and are not due to obstruction by the plaque itself. It’s what happens to that plaque that causes heart attacks.
What is Plaque?
Although the names are similar, coronary artery plaque has nothing to do with the plaque that is present on your teeth. In the coronary arteries, plaque is another name for atherosclerosis, the process that gradually blocks flow through the artery like corrosion in a pipe.
From early childhood onwards, the walls of your arteries start to change. The earliest change is the deposition of cholesterol into the arterial wall to form a “fatty streak”. These fatty streaks are often present in the teen years. Over subsequent years, the fatty streak accumulates more cholesterol as well as inflammatory cells, such as macrophages ( a type of white blood cell), fibroblasts (which secrete connective tissue proteins) and muscle cells. Over time, the fatty streak is transformed into a “plaque”. As the plaque grows it gradually thickens and can start to intrude into the center of the artery, ultimately impeding blood flow.