Elevated levels of C-reactive protein (CRP), a blood-marker for inflammation, is a better predictor of risk for heart attacks than high low-density lipoprotein (LDL) cholesterol levels, report researchers involved in the US-based Women's Health Study.
The researchers, who studied more than 27,000 women in the ongoing study, noted that a combined evaluation of CRP and LDL may be a better method of risk detection because they appear to complement each other. They caution, however, that more data needs to be collected on CRP before these results can be translated into clinical practice.
CRP measures the level of inflammation in the bloodstream which weakens the walls of blood vessels, making fatty buildups burst, causing heart attacks. A report on the currently unpublished study by Associated Press said that the research finds that inflammation is twice as likely as high cholesterol to trigger heart attacks.
"We believe CRP measurement should be seriously evaluated as part of a strategy in assessing an individual's global cardiovascular disease risk," said Dr Robert O. Bonow, president of the American Heart Association. Global risk estimation combines information from all existing risk factors, such as elevated LDL, high blood pressure and smoking status, to determine a person's overall risk for developing cardiovascular disease in the next ten years.
Diet and exercise can lower CRP considerably, but statins and other medicines are also effective.
"As the study authors note, many individuals who have a cardiovascular event, such as a heart attack, have LDL cholesterol levels below 130 milligrams per decilitre, which means they may not have met criteria for lowering LDL with medications prior to their heart attack. However, a large-scale clinical trial should be able to determine if individuals with low LDL but elevated CRP may ultimately be good candidates for medical therapy with statin drugs, because these cholesterol-lowering drugs also seem to lower CRP levels," Bonow said.
"These results from the Women's Health Study also give credence to the growing body of evidence suggesting that atherosclerosis is an inflammatory process," he added.Inflammation is the body's response to injury, and is believed to be a key component of atherosclerosis, the disease process that causes fatty deposits to build up in the lining of arteries.
The causes for the low-grade inflammation that may increase the risk of cardiovascular disease are uncertain, but experts believe that a bacterial or viral infection might contribute to or cause atherosclerosis. Additionally, it is still not certain whether the CRP elevations are a result of atherosclerosis, rather than a marker for a causative agent, such as a bacteria or virus.
Determining the association between CRP and CVD risk is important, because it may lead to better treatments for preventing heart attack and stroke.
The American Heart Association and the US Centers for Disease Control and Prevention will be issuing a joint report within the coming months that will include recommendations on CRP screening. The subject will also be the focus of a special session during the American Heart Association's annual Scientific Sessions in Chicago next week.