Cardiac biomarkers in the intensive care unit

Abstract

Cardiac biomarkers (CB) were first developed for assisting the diagnosis of cardiac events, especially acute myocardial infarction. The discoveries of other CB, the better understanding of cardiac disease process and the advancement in detection technology has pushed the applications of CB beyond the 'diagnosis' boundary. Not only the measurements of CB are more sensitive, the applications have now covered staging of cardiac disease, timing of cardiac events and prognostication. Further, CB have made their way to the intensive care setting where their uses are not just confined to cardiac related areas. With the better understanding of the CB properties, CB can now help detecting various acute processes such as pulmonary embolism, sepsis-related myocardial depression, acute heart failure, renal failure and acute lung injury. This article discusses the properties and the uses of common CB, with special reference to the intensive care setting. The potential utility of "multimarkers" approach and microRNA as the future CB are also briefly discussed.

Figure 1

The development of cardiac biomarkers. ADM, adrenomedullin; BNP, B-type natriuretic peptide; CAM, cell adhesion molecule; CK-MB, creatine kinase-MB; CRP, C-reactive protein; cTn, cardiac troponin; H-FABP, human fatty-acid binding protein; HSP, heat shock protein; IL, interleukin; IMA, ischemia-modified albumin; INFγ, interferon γ; LP-LPA₂, lipoprotein-associated phospholipase A₂; PAPP, pregnancy-associated plasma protein; ROS, reactive oxygen species; sCD40L, soluble CD40 ligand.

Figure 2

Evolution of cardiac dysfunction and the associated changes in cardiac biomarkers. (see legend to Figure 1 for abbreviations).

Figure 3

Contributors to circulating BNP level.