C-Reactive Protein and Parental History Improve Global Cardiovascular Risk Prediction

Abstract

Background— High-sensitivity C-reactive protein and family history are independently associated with future cardiovascular events and have been incorporated into risk prediction models for women (the Reynolds Risk Score for women); however, no cardiovascular risk prediction algorithm incorporating these variables currently exists for men. Methods and Results— Among 10 724 initially healthy American nondiabetic men who were followed up prospectively over a median period of 10.8 years, we compared the test characteristics of global model fit, discrimination, calibration, and reclassification in 2 prediction models for incident cardiovascular events, one based on age, blood pressure, smoking status, total cholesterol, and high-density lipoprotein cholesterol (traditional model) and the other based on these risk factors plus high-sensitivity C-reactive protein and parental history of myocardial infarction before age 60 years (Reynolds Risk Score for men). A total of 1294 cardiovascular events accrued during study follow-up. Compared with the traditional model, the Reynolds Risk Score had better global fit (likelihood ratio test P <0.001), a superior (lower) Bayes information criterion, and a larger C-index ( P <0.001). For the end point of all cardiovascular events, the Reynolds Risk Score for men reclassified 17.8% (1904/10 724) of the study population (and 20.2% [1392/6884] of those at 5% to 20% 10-year risk) into higher- or lower-risk categories, with markedly improved accuracy among those reclassified. For this model comparison, the net reclassification index was 5.3%, and the clinical net reclassification index was 14.2% (both P <0.001). In models based on the Adult Treatment Panel III preferred end point of coronary heart disease and limited to men not taking lipid-lowering therapy, 16.7% of the study population (and 20.1% of those at 5% to 20% 10-year risk) were reclassified to higher- or lower-risk groups, again with significantly improved global fit, larger C-index ( P <0.001), and markedly improved accuracy among those reclassified. For this model, the net reclassification index was 8.4% and the clinical net reclassification index was 15.8% (both P <0.001). Conclusions— As previously shown in women, a prediction model in men that incorporates high-sensitivity C-reactive protein and parental history significantly improves global cardiovascular risk prediction.