Using higher cut-off values to diagnose acute myocardial infarction in patients with elevated hs-cTnT

It is often challenging to diagnose acute myocardial infarction (AMI) in patients with elevated high-sensitivity cardiac troponin T (hs-cTnT) before a significant rise and/or fall of hs-cTnT can be observed. This study aimed to find an optimal cut-off to rule in AMI. A total of 76411 patients with elevated hs-cTnT were included. The predictive cut-off values for diagnosing ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) were assessed by the area under the receiver operating characteristic curves (AUC). Among the patients, 50466 (66.0%) had non-cardiac diseases, 25945 (34.0%) had cardiac diseases, and 15502 (20.3%) had AMI, including 816 (1.1%) with STEMI and 14686 (19.2%) with NSTEMI. The median hs-cTnT level was 3788.0 ng/L in STEMI patients and 67.2 ng/L in NSTEMI patients. The optimal cut-off for diagnosing STEMI was 251.9 ng/L, with a sensitivity of 90.7%, specificity of 86.5%, and an AUC of 0.942; the optimal cut-off for diagnosing NSTEMI was 130.5 ng/L, with a sensitivity of 40.9%, specificity of 83.8%, and an AUC of 0.638. In patients with elevated hs-cTnT, optimizing the cut-off values for diagnosing STEMI and NSTEMI to 251.9 ng/L and 130.5 ng/L, respectively, demonstrated high accuracy in a large cohort of Chinese patients.