Emerging evidence suggests that very low hs-cTnI concentrations at presentation can identify half of all patients as low risk.12, 26, 27 Similar observations have been reported for cardiac troponin T,28, 29 and risk stratification thresholds below the 99th centile have been incorporated into early rule-out pathways.30, 31, 32, 33, 34 The 2016 European Society of Cardiology guidelines35 recommend the use of pathways that incorporate thresholds below the 99th centile and small changes in cardiac troponin to improve both the rule-in and rule-out of myocardial infarction. Here, TNNI3 is linked to myocardial infarction.