Predicting Heart Attack Risk

Atherosclerosis and Coronary Artery Disease
Atherosclerosis is a disease of the arteries caused by an accumulation of fatty deposits and plaque along portions of the inner walls of the vessels. Like a clog in a drain, over time, the plaque can narrow the affected section of the artery and slow or block the flow of blood. In some cases, a clot gets trapped in the narrowed artery and blocks blood flow. In the heart, a severely narrowed or blocked artery means a part of the heart muscle doesn't get enough oxygen, and the affected area may die. This is a heart attack, or myocardial infarction. Patients can also experience sudden cardiac death when a section of plaque ruptures or breaks open. That releases fats and other plaque components into the blood. Clots form when the body attempts to stop the bleeding and "heal" the damage. Those clots can quickly block the opening through the artery.

Coronary artery disease is the leading cause of death for American men and women. This year, the American Heart Association estimates about 1.1 million people in the U.S. will have a heart attack. About 45 percent of the victims will die within one year. Risk for a heart attack increases with age. The average age for a first heart attack is 65.8 for men and 70.4 for women. Some other risk factors include: family history of heart disease, smoking, high blood pressure, elevated cholesterol levels, diabetes, obesity, and lack of regular exercise.

C-Reactive Protein and Heart Disease
Research from the National Institutes of Health has found about 50 percent of men and 63 percent of women who die suddenly from coronary artery disease have no prior symptoms of heart disease. So other factors are believed to be involved in the development of heart disease. One potential suspect is a protein called C-reactive protein (CRP). It's made by the liver, and levels appear to increase in response to inflammation. Normal levels are generally less than 5 mg/dL of blood. But within four to eight hours after the onset of some type of inflammatory event, levels of CRP can rise from 20 to 500 mg/dL.

Researchers have discovered that elevated levels of CRP are associated with an increased incidence of cardiovascular disease. In two major studies (the Physicians' Health Study and the Women's Health Study) patients with the highest levels of CRP had a three-fold increased risk of heart attack and a two-fold increased risk for stroke. A recent study in the journal, Circulation, reports elevated levels of CRP are also associated with an increased risk for plaque rupture and sudden cardiac death.

What does all this mean for the average person? There's a relatively inexpensive blood test, called the hs-CRP (high-sensitivity C-reactive protein). The test can be incorporated into the same blood test used for measuring fasting cholesterol levels. If a patient is found to have elevated CRP levels, doctors can recommend steps to reduce the risk of a serious or fatal heart attack (such as taking statins, medications which reduce inflammation). Researchers issue an important caution. Elevated levels of CRP may not necessarily be caused by cardiovascular disease. CRP can also an indication of inflammation from rheumatoid arthritis, rheumatic fever, cancer, tuberculosis, pneumonia, or systemic lupus erythematosus. So it may take some skilled detective work to find the root of the problem.


For general information C-reactive protein and heart disease, contact your local chapter of the American Heart Association, or visit their website at