Cardiac biomarkers: where are we going?

The measurement of cardiac troponins (cTn) is recommended by all guidelines as the gold standard for the detection of differential myocardial injury and acute myocardial infarction (AMI). In this article, some key issues regarding both analytical characteristics of the high-sensitivity methods for cTn, which are still considered controversial or unresolved are discussed in details. These issues have been included in the activities of the Joint Working Group on "Cardiac Biomarkers" of the Italian Society of Clinical Biochemistry and the Italian branch of the European Ligand Assay Society. The major clinical concern regarding hs-cTn methods is the difficulty to differentiate the pathophysiological mechanism responsible for biomarker release from cardiomyocytes after reversible or irreversible injury, respectively. High-sensitivity cTnI and cTnT methods (hs-cTn) enable to monitor myocardial renewal and remodelling, and to promptly identify patients at highest risk of heart failure. In addition, several studies demonstrated that the cardiovascular risk progressively increases in the general population even for hs-cTn values well below the 99th percentile, i.e. the recognized cut-off for the detection of myocardial injury and diagnosis of AMI. An early and effective treatment of individuals at higher cardiovascular risk may revert the initial myocardial remodelling and slow down heart failure progression. Finally, recent studies support the working hypothesis that a new generation of hs-cTn methods should be set up based on monoclonal antibodies, specific for circulating peptide forms more characteristics for reversible rather than irreversible myocardial injury. Of course, screening programs of cardiovascular risk stratification and prevention strategies using hs-cTn methods require further investigation to define the optimal target populations, timing of measurement, and preventive interventions.