Medical Device Link.

Originally Published IVD Technology June 2004

INDUSTRY NEWS

Figure 1. C-reactive protein was found to have a weaker association with CHD than other risk factors, including systolic blood pressure, cigarette smoking, and total cholesterol. Source: The New England Journal of Medicine (1 April 2004) (click to enlarge).

The importance of C-reactive protein (CRP testing) as an indicator of coronary heart disease (CHD) may be lower than was previously believed. In 2003, the American Heart Association (AHA; Dallas) stated that it is reasonable to measure CRP as an adjunct to the measurement of established risk factors in order to assess the risk of CHD. However, a report in the April 1 issue of the New England Journal of Medicine (NEJM) may challenge this recommendation.

The authors of the NEJM report conclude that CRP is merely a moderate predictor of heart disease and suggest that “recommendations regarding its use in predicting the likelihood of coronary heart disease may need to be reviewed.”

The report was based on a study of roughly 2400 patients with either CHD or myocardial infarction, and 4000 controls. The large size of the cohort adds to the validity of the study’s findings. According to a commentary on the study published in the same issue of NEJM, this population was “by far the largest number of cases that have been examined in such analyses.” 

However, the study participants reside in Iceland, and the Icelandic population may be less racially diverse and less obese than the U.S. population. Because of this disparity, the findings may not be readily applicable to the U.S. or other populations that differ significantly from that of Iceland. 

Nonetheless, the accompanying commentary touts the strengths of the study design and the data analysis. The commentary states that the study findings “confirm pioneering work showing that the CRP level is an indicator of the risk of CHD, [but] they call into question the magnitude of the effect.” 

Some members of the IVD industry were not surprised by the results of the study. In spite of the recommendations of the AHA, David Carville, PhD, president of Causeway Scientific (Mishawaka, IN) says, “CRP is not an established test. It is currently a boutique assay that requires additional testing to define its value. Unfortunately, the studies that indicate that it is great [for assessing CHD risk] are mainly funded by companies with the assay.”

In addition, industry experts suspect that the results of this particular study may not affect the market demand for CRP testing. According to Vana Smith, PhD, an industry insider with expertise in cardiac testing, “Expectations and predictions for new markers have to be balanced with other market forces, including the rising pressure to control healthcare costs, insurance coverage and reimbursement rates, and the ease of access to low-cost preventative measures (e.g., aspirin, vitamins, etc.). The recent study from NEJM is not the first to question the relative importance of a new marker and its role in predicting coronary heart disease. I don’t see a significant impact on the market as a result of this study.”

The study, titled “C-Reactive Protein and Other Circulating Markers of Inflammation in the Prediction of Coronary Heart Disease,” and its accompanying commentary, “C-Reactive Protein Reassessed,” can be purchased from the New England Journal of Medicine Web site at www.nejm.org. 

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