Atherosclerosis: What’s Happening Inside Your Arteries?
Could atherosclerosis already be clogging your arteries?
Atherosclerosis: Inflammation in Your Arteries
How does a plaque become inflamed? As plaques grow, leukocytes and muscle cells gather inside. The leukocytes attempt to digest the LDL cholesterol.
That may sound like a good thing. But leukocytes' job description includes releasing chemicals that can be destructive. The local muscle cells also release damaging substances.
The result can be a dissolving of the interior of a stable plaque, rendering it unstable. If the cap of the plaque breaks off, dangerous materials inside are exposed to blood flowing by. A blood clot forms rapidly in the artery, causing a heart attack or stroke.
Severe but stable blockages can often be seen on a stress test or coronary angiogram. However, smaller, dangerous plaques usually go undetected. And with current knowledge, "it's impossible to determine when these plaques are inflamed and therefore more likely to rupture," explains Borer.
Using a marker in the blood called C-reactive protein (CRP), doctors can get a general idea of the level of inflammation in the body. This test can't predict heart attacks or strokes with accuracy, though.
Atherosclerosis: Calcium and Hardening of the Arteries
Why is atherosclerosis often described as "hardening of the arteries?" As plaques grow and evolve in the artery walls, calcium deposits inside them. The calcium makes the plaque firm and the artery stiffer. In general, stable plaques contain more calcium.
A relatively new test called electron-beam computed tomography (EBCT) can calculate the amount of calcium in the coronary arteries and help predict the risk of heart attack in certain people.
Atherosclerosis: Reducing Your Risk
Atherosclerosis is frightening because its complications can be both unpredictable and deadly. However, it's worth remembering that up to 90% of the risk of a first heart attack is preventable. The risk factors are well known, and most can be prevented or treated.
Smoking: Tobacco smoke damages endothelium and accelerates atherosclerosis. Smoking also increases inflammation, the process that makes plaques unstable. On the other hand, "if you quit smoking, after a few years your risk falls nearly to that of a nonsmoker," says Borer.
Sedentary lifestyle: Exercise keeps arteries' endothelium healthy. This helps explain why frequent exercise dramatically reduces the risk of atherosclerosis. Exercise also reduces the risk of diabetes, another cause of atherosclerosis. Thirty minutes a day provides a large benefit, but any exercise is better than none.
High blood pressure and cholesterol: If you're leaving your blood pressure untreated, your arteries are taking the pounding. Lowering cholesterol to healthy levels is proven to reduce the risk of heart attacks. Some people can achieve healthy blood pressure and cholesterol levels with lifestyle changes alone. Many, though, will require medicines to reduce the risk.
What you don't see can hurt you. Until we can see inside our arteries, the best advice is to start lowering your risk for atherosclerosis now.
"Without question, reducing your risk factors will lower your chances of dying from cardiovascular disease," the most common killer of Americans, says Schaefer.