Determination of C-reactive protein (CRP) level has been suggested to improve cardiovascular disease (CVD) risk assessment. This study examines the utility of CRP levels to assess CVD risk in a community setting.
We performed a prospective observational cohort study on a community population sample. A total of 1949 men and 2497 women without CVD from the Framingham Heart Study underwent CVD risk factor assessment. Initial CVD events during 8 years of follow-up were recorded.
There were 283 major CVD and 160 major coronary heart disease incident events. Age-, sex-, and multivariable-adjusted analyses generally used CRP level categories of less than 1, 1 to 3, and greater than 3 mg/L. In age- and sex-adjusted models, the traditional risk factors and elevated CRP levels indicated increased risk. The age- and sex-adjusted relative risk (RR) and 95% confidence interval (CI) of CRP level greater than 3 mg/L for major CVD was elevated (RR, 1.60; 95% CI, 1.19-2.14), with evidence of attenuation (RR, 1.22; 95% CI, 0.90-1.66) in multivariable models. The C statistic, a measure of the discriminatory capability of the prediction models, was 0.74 for prediction of major CVD with age and CRP level. In multivariable models that included traditional risk factors, the C statistic was 0.78, a value that was unchanged with the addition of CRP to the multivariable model. Similar relations were noted for major coronary heart disease events.
Elevated CRP level provided no further prognostic information beyond traditional office risk factor assessment to predict future major CVD and major coronary heart disease in this population sample.