The Role of Cardiac Biomarkers in the Diagnosis and Management of Patients Presenting with Suspected Acute Coronary Syndrome

Myocardial infarction (MI) is the leading cause of death in the developed world. Biomarkers have an essential role in diagnosis, risk stratification, guiding management and clinical decision making in the setting of patients presenting with signs and symptoms of MI. Cardiac troponin (cTn) rose to prominence during the 1990s and has evolved to be the cornerstone for diagnosis of MI. The current criteria for MI diagnosis include a rise and/or fall in cTn with at least one value above the 99th percentile of the upper reference limit. Along with cTn, the natriuretic peptides B-type natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) have an important role in determining prognosis and guiding management. As assays for cTn have been evolved that are capable of reliably detecting smaller and smaller quantities in the blood, a dilemma has emerged as to how to use this new information. Several studies have attempted to answer this question and have shown that these lower concentrations of cTn have important prognostic significance and, more importantly, that intervention in these patients leads to improved clinical outcomes. New algorithms incorporating BNP, NT-proBNP, and more sensitive cTn assays hold promise for more rapid diagnosis or rule-out of MI, allowing for appropriate management steps to be initiated and more efficient and effective utilization of healthcare resources.