Myocardial injury biomarkers and their assays: advances, insights, and future directions.

Abstract

Introduction: Cardiac Troponin (cTn) is fundamental to the diagnosis of myocardial injury. High sensitivity cTn assays have transformed acute cardiac care by shifting the focus toward rapid rule-out of myocardial infarction, allowing the early identification and safe discharge of low-risk patients. However, cTn proteins and their assays have limitations.

Areas covered: The review summarizes cTn as a biomarker of myocardial injury, high-sensitivity cTn assay performance, and their combined impact on chest pain pathways. It explores Cardiac Myosin-Binding Protein C (cMyC) and discusses the evidence behind its use as an alternative biomarker. Studies available on Pubmed were analyzed using keywords cTn, cMyC, myocardial infarction, triage, chest pain and assay. The second half of this review explores the proteolysis of both these biomarkers, and how this information could be used in clinical practice.

Expert opinion: Both hs-cTn and hs-cMyC assays have shown equivalent diagnostic performance in the rule-out of myocardial infarction. Unfortunately, both are also plagued by the similar liabilities: decreased specificity for Type 1 AMI, and an inability to distinguish between types of myocardial injury. Proteolysis of each biomarker differs according to underlying pathology. Novel assays that quantify distinct forms could enhance patient triage.