Is the true clinical value of high-sensitivity troponins as a biomarker of risk? The concept that detection of high-sensitivity troponin 'never means nothing'.

INTRODUCTION: High-sensitivity troponin (hs-cTn) assays are central to the diagnosis of myocardial infarction (MI). Their increased sensitivity has facilitated rapid pathways for the exclusion of MI. However, hs-cTn is now more readily detectable in patients without symptoms typical of MI, in whom a degree of myocardial injury is assumed. Recently, the practice of using the 99th centile of hs-cTn as a working 'upper reference limit' has been challenged. There is increasing evidence that hs-cTn may provide useful prognostic information, regardless of any suspicion of MI, and as such these assays may have potential as a general biomarker for mortality. This raises the concept that detection of hs-cTn 'never means nothing.' AREAS COVERED: In this review, we will evaluate the evidence for the use of hs-cTn assays outside their common clinical indication to rule out or diagnose acute MI. EXPERT OPINION: The data presented suggest that hs-cTn testing may in the future have a generalized role as a biomarker of mortality risk and may be used less as a test for ruling in acute MI, but will remain a frontline test to exclude that diagnosis in ED. Further, the data suggest that the detection of hs-cTn 'never means nothing.'

Cardiogenic shock due to acute severe ischemic mitral regurgitation.

The reduction in patients presenting with ST-elevation myocardial infarction (STEMI) during the COVID19 crisis could have resulted from fears about developing COVID-19 infection in hospital. Patients who delay presenting with STEMI are more likely to develop mechanical complications, including acute ischemic mitral regurgitation (MR). We present a 69-year-old women with an inferior STEMI and cardiogenic shock due to acute ischemic MR who delayed presenting to hospital due to the fear of COVID-19. Early identification of this mechanical complication using transthoracic echocardiography in the Emergency Department enabled the team to target her optimisation. Ultimately these patients require urgent surgery to repair the mitral valve and revascularize the myocardium but they are often too unwell to undergo surgery and even when it is feasible the outcomes are poor.