C-reactive protein and the 10-year incidence of coronary heart disease in older men and women - The cardiovascular health study

Background - High C-reactive protein (CRP) is associated with increased coronary heart disease risk. Few long-term data in the elderly are available. Methods and Results - Baseline CRP was measured in 3971 men and women >= 65 years of age without prior vascular diseases; 26% had elevated concentrations ( > 3 mg/ L). With 10 years of follow-up, 547 participants developed coronary heart disease (CHD; defined as myocardial infarction or coronary death). With elevated CRP, the 10-year cumulative CHD incidences were 33% in men and 17% in women. The age-, ethnicity-, and sex-adjusted relative risk of CHD for CRP > 3 mg/ L compared with < 1 mg/ L was 1.82 (95% CI, 1.46 to 2.28). Adjusting for conventional risk factors reduced the relative risk to 1.45 ( 95% CI, 1.14 to 1.86). The population-attributable risk of CHD for elevated CRP was 11%. Risk relationships did not differ in subgroups defined by baseline risk factors. We assessed whether CRP improved prediction by the Framingham Risk Score. Among men with a 10-year Framingham-predicted risk of 10% to 20%, the observed CHD incidence was 32% for elevated CRP. Among women, CRP discriminated best among those with a 10-year predicted risk > 20%; the incidences were 31% and 10% for elevated and normal CRP levels, respectively. Conclusions - In older men and women, elevated CRP was associated with increased 10-year risk of CHD, regardless of the presence or absence of cardiac risk factors. A single CRP measurement provided information beyond conventional risk assessment, especially in intermediate-Framingham-risk men and high-Framingham-risk women.