Update on global conversion to high sensitivity cardiac troponin assays

Progressive improvements in immunoassay performance for cardiac troponin (cTn) has resulted in the current generation of high sensitivity assays. These are characterised by the ability to measure troponin with high precision. The most important aspect is that they are able to measure levels below the 99 th percentile with some able to measure values close to the population lower reference limit. Rapid predictive algorithms to support early classification of patients presenting with chest pain into those at high, intermediate or low risk of developing myocardial infarction (MI) utilising these high sensitivity assays have been developed. High sensitivity troponin assays have now been made available worldwide. Implementation into routine clinical practice has occurred at different rates globally. The major challenge to initial adoption has been largely due to regulatory acceptance. In some areas there have been financial constraints but this has largely influenced the transition from conventional "cardiac enzyme" measurement to troponin measurement rather than the conversion to a high sensitivity assay. Clinical utilisation has largely been with replacement of the previous generation troponin assay with a high sensitivity assay. There have been significant delays in implementing novel rapid diagnostic pathways that exploit the ability to discharge on single sample measurement on admission as well as rapid predictive algorithms. There also appears to be widespread use of high sensitive troponin measurements in a range of emergency department (ED) populations beyond those with chest pain. The challenge with implementing these assays is their use in the appropriate population and the feasibility of implementing the rapid diagnostic protocols that high sensitivity assays support.