A Tale of Two Biomarkers: The Use of Troponin and CK-MB in Contemporary Practice

Extract

In its Fall, 2009 issue, Clinical Laboratory Science featured a Focus Series on Cardiovascular Risk Assessment. This series contained articles on B-type natriuretic peptide and genetic markers of cardiovascular disease and explored the links between decreased serum vitamin-D levels and cardiovascular disease. Traditionally, cardiovascular risk assessment has referred to markers that help predict long-term mortality and morbidity for heart disease. Markers like LDL, HDL, triglycerides, total cholesterol, hsCRP, BNP and many others make up this group. Acutely however, in cases of suspected myocardial infarction, cardiovascular assessment relies on a very different class of serum markers. Measurement of CK-MB and troponin proteins allows us to confirm or rule out damage to the myocardium. These markers are in obvious contrast to risk markers that are used as tools to assess a person's future risk for cardiovascular events. When considering markers for myocardial infarct, laboratorians know that CK-MB and troponin are both used to give diagnostic and sometimes even prognostic information. In this article, which is an extension of the Fall 2009 Focus series, we review the progress of these two myocardial markers while contemplating the question, ‘is it time to phase-out CK-MB testing given the advances and advantages of troponin testing?’

Modern diagnosis of myocardial infarction includes the use of blood biomarkers, which can also be used for risk assessment and for guiding interventional and non-interventional therapies. An ideal marker of cardiac necrosis should exhibit the following characteristics: cardiac specificity, tissue sensitivity, early and stable release after necrosis, predictable clearance, and the…