Rapid myocardial infarction rule-out: A single high-sensitivity cardiac troponin I and T threshold strategy for the Chinese emergency department.

BACKGROUND: High-sensitivity cardiac troponin (hs-cTn) discerns MI with high sensitivity, facilitating swift ED discharge. Yet, its application in Chinese cohorts is understudied. This study seeks optimal hs-cTnI and hs-cTnT thresholds for low-risk patient identification in Chinese EDs, utilizing Abbott and Roche assays. METHODS: This prospective, observational cohort study included ED patients suspected of having acute coronary syndrome (ACS). Patients with ST-segment elevation myocardial infarction (STEMI) were excluded. Plasma hs-cTnI and hs-cTnT levels were assessed at presentation. This study evaluated the negative predictive value (NPV) of hs-cTn for 30-day adverse events and targeted ≥99% sensitivity and NPV for MI. The outcomes were compared with those of the clinical hs-cTn assay. RESULTS: Among the 1225 enrolled patients, 365 (29.8%) were confirmed to have MI. A derivation hs-cTnI concentration of <5 ng/L provided a sensitivity of 99.2% and negative predictive value of 99.4% for ruling out MI. For hs-cTnT, sensitivity and NPV were both 100% when the concentration was below 5 ng/L for ruling out MI. The proportions of patients classified as low risk were 42.53% for hs-cTnI and 12.98% for hs-cTnT. Both the hs-cTnI and hs-cTnT thresholds demonstrated high sensitivity and NPV in the prediction of 30-day adverse events. Sex-specific rule-out thresholds (hs-cTnI <6 ng/L, hs-cTnT <8 ng/L) exceeded the unified 5 ng/L, whereas no female-specific threshold was superior for either assay. CONCLUSION: Singular assessment of hs-cTnI and hs-cTnT levels is a rapid and reliable strategy for identifying MI, which may facilitate timely patient discharge from the ED.