Atherosclerosis is characterized by a non-specific local inflammatory process accompanied by a systemic response. A number of prospective studies in initially healthy subjects and in patients with manifest atherosclerosis have now convincingly demonstrated a strong and independent association between even slightly elevated concentrations of various systemic markers of inflammation and a number of cardiovascular endpoints. Measurements of inflammatory markers might also add to the predictive value of atherogenic lipoprotein phenotyping in assessing long-term coronary risk. This suggests that the evaluation of the 'activeÔÇÖ inflammatory state of patients with manifest atherosclerosis yields important complementary prognostic information.
Currently, C-reactive protein (CRP), the classical acute-phase protein, seems to be the marker of choice for the clinical situation. However, there are other emerging biomarkers, such as lipoprotein-associated phospholipase A2 (Lp-PLA2), oxidized low-density lipoprotein (oxLDL), interleukin (IL)-18 and adiponectin, that might improve our ability to identify patients at risk for future coronary heart disease (CHD).
Several studies published during the past decade have provided strong evidence that CRP, although a classical acute-phase reactant with a relatively short half-life (about 19 hours), represents a reliable long-term marker of cardiovascular risk. So far, the results from more than 25 different prospective studies have been reported, and they clearly demonstrate a significant and independent association between increased concentrations of CRP and future cardiovascular events. Furthermore, the recent American Health Association (AHA)/US Centers for Disease Control and Prevention (CDC) consensus report recommends only the measurement of CRP in asymptomatic subjects at intermediate risk for future coronary events (10-year risk of 10% to 20%) and in selected patients after an acute coronary syndrome. This recommendation was based on the fact that of the current inflammatory markers identified, high-sensitivity (hs)-CRP has the analyte and assay characteristics most conducive to use in practice (class 2a, level of evidence B), and that other inflammatory markers should not be measured for determination of cardiovascular (CV) risk in addition to hs-CRP (class 3, level of evidence C).