Guidelines for CRP Testing

A panel of experts has recommended limited use of a new blood test for c-reactive protein (CRP), a marker of inflammation that has been widely promoted for assessing the risk of heart disease. This recommendation and other guidelines were published in the January 28, 2003, issue of Circulation.

The panel was convened by the American Heart Association (Dallas, TX, USA) and the US Centers for Disease Control and Prevention (CDC, Atlanta, GA, USA), following widespread publicity and the rush of many individuals to ask their doctors for the test.

Several studies have shown that increased concentrations of CRP appear to be associated with an increased risk for coronary heart disease, sudden death, and peripheral arterial disease. Thus, the test can be an independent marker of this risk and may be useful as a discretionary tool for evaluating people with moderate risk. This group includes people with a 10-20% risk for heart attack in the next 10 years based on their health status and history. However, the panel does not consider the new test in the same category as cholesterol testing or high blood pressure screening. In addition, there is no evidence as yet that treatment strategies based on CRP levels can improve survival.

The panel reports that the results of CRP tests should be expressed as milligrams per liter (mg/l), with concentrations of less than 1.0 mg/l defined as low risk, 1.0-3.0 mg/l as average risk, and concentrations higher than 3.0 mg/l defined as high risk. Those in the high-risk group have about a two-fold increase in relative risk for cardiovascular disease compared to those in the low-risk group.

"Although our statement identifies a subgroup of patients who may benefit from CRP testing, for most patients the emphasis must remain on detection, treatment, and control of the major risk factors, such as high blood pressure, high blood cholesterol, cigarette smoking, and diabetes,” said Thomas A. Pearson, M.D., Ph.D., co-chair of the panel and associate dean for clinical research at the University of Rochester School of Medicine and Dentistry (Rochester, NY, USA).




Related Links:
American Heart Association
Centers for Disease Control (CDC)