How to use C-reactive protein in acute coronary care

Abstract

C-reactive protein is an acute phase protein and an established marker for detection, risk stratification, and monitoring of infections and inflammatory and necrotic processes. Because C-reactive protein is sensitive but not specific, its values must be interpreted in the clinical context. In patients with acute myocardial infarction (AMI), C-reactive protein increases within 4–6 h of symptoms, peaks 2–4 days later, and returns to baseline after 7–10 days.1 C-reactive protein has gained interest recently as a marker for risk stratification in acute coronary syndrome (ACS) when measured by high-sensitivity C-reactive protein assays. These assays have greater analytical sensitivity and reliably measure C-reactive protein concentrations within the reference range with low imprecision (5–10%).2 Because of evidence that atherosclerosis is an inflammatory disease, high-sensitivity C-reactive protein can be used as a biomarker of risk in primary prevention and in patients with known cardiovascular disease.3 The aim of this review is to evaluate the use of C-reactive protein in patients with acute coronary disease. C-reactive protein is a non-specific first-line host defence mechanism.4 With stimulation by cytokines (e.g. interleukins and tumour necrosis factor-alpha), C-reactive protein synthesis in hepatocytes occurs within 4–6 h. Concentrations can rise 1000-fold or more over 24–48 h. C-reactive protein has been detected in atherosclerotic plaques; its possible role in atherosclerogenesis is summarized in Figure 1 , but is still a matter of debate.5 Genetic variants account for 35–40% of the variability in high-sensitivity C-reactive protein.6 Figure 1 Possible pathophysiological effects of C-reactive protein in atherosclerosis. Aggregated C-reactive protein selectively binds LDL and VLDL in serum, thereby potentially participating in the mechanisms involved in plaque formation and destabilization, and shows some of the key properties of antibodies and may contribute to immune responses by activation of antigen presenting cells. Procoagulant effects have been reported in vitro as …