Coronary artery disease takes the lives of more than 450,000 Americans annually. Sixteen million people alive today have a history of heart attack or angina or both. But coronary artery disease actually is the end product of the very complex process called atherosclerosis, more commonly known as hardening of the arteries.
Atherosclerosis is a process in which deposits of fatty substances, cholesterol and cellular waste products build up on the inside of the artery wall. The resulting buildup is called plaque.
We’ve known for a long time that fat, cholesterol, smoking and hypertension can all aggravate or worsen the atherosclerotic process. But a recent study suggests that a common virus, cytomegalovirus (CMV), also may contribute to the process by infecting the cells that line the walls of the artery, causing them to multiply and grow in an uncontrolled manner. These findings suggest that not only are our arteries being blocked by plaque, but at least in some cases, there is an overgrowth of arterial cells that cause the artery wall to bulge inward, narrowing it even further.
In this study, researchers examined the plaque buildup taken from patients who had previously undergone a procedure known as angioplasty, and whose arteries had narrowed again soon after.
This study is not the first time anyone has suggested that “blocked” arteries could partly result from uncontrolled cell growth. And the theory that a virus could be the starting point for blocked arteries has been in existence for decades. Plus, heart disease researchers repeatedly have found certain viruses, CMV in particular, associated with plaque. But does CMV help create the plaque or is its presence just a coincidence? More research is needed to answer that question.
The CMV infection is very common, and by the age of 35, half of the population has been infected with it. It usually does not cause symptoms and remains dormant in the body for life. Why then does it reactivate and cause uncontrolled cell growth in the artery walls of some people? Some believe that although it can be reactivated by trauma, infection, stress or immune system suppression, it is more likely to be reactivated as people grow older. If research can explain how and why CMV reactivates, we might be closer to learning how to prevent this reactivation.
Whether a virus is ultimately found to play a major role in atherosclerosis or not, there still are many things you can do to lower heart disease risk. Are your blood pressure and fat intake higher than they should be? Is your activity level lower than it should be? Are you still smoking? These are all things that you can control. So talk to your doctor about the lifestyle changes you should make to stay in good heart health.