Bularga A, Lee KK, Stewart S, et al. - Researchers assessed safety as well as the efficacy of risk stratification thresholds for high-sensitivity cardiac troponin in patients with suspected acute coronary syndrome. Myocardial infarction or cardiac death within 30 days was assessed as the primary outcome. They excluded patients with myocardial injury at presentation, with ≤ 2 hours of symptoms or with ST-segment elevation myocardial infarction. For the primary outcome, the negative predictive value (NPV) was 99.8% in those with cardiac troponin I levels <5 ng/L and 99.9% in those with levels <2 ng/L. In men and women and across all age groups, consistent NPV was observed at both thresholds, although a reduction in the proportion of patients recognized as low risk was evident with increasing age. At 12 months, the risk of myocardial infarction or cardiac death was found to be 77% and 80% lower in patients with cardiac troponin I levels < 5 ng/L and in those < 2 ng/L, respectively, relative to those with cardiac troponin I levels ≥ 5ng/L but < 99th centile. With the use of risk stratification thresholds, it was possible to identify patients with suspected acute coronary syndrome and at least 2 hours of symptoms as low-risk at presentation regardless of age and gender.