Performance of the ESC 0/1 h hs-cTnI algorithm in suspected NSTEMI patients with normal versus abnormal...

To evaluate the diagnostic and prognostic performance of the ESC 0/1-h high-sensitivity cardiac troponin I(hs-cTnI) algorithm in emergency department patients with suspected non-ST-segment elevation myocardial infarction(NSTEMI), stratified by by initial electrocardiogram (ECG) findings.

This retrospective analysis included 1535 patients with suspected ACS. Based on initial ECG, patients were categorized into normal (n = 888) or abnormal (n = 647) groups,with the abnormal group further stratified into ischemic (n = 464) and non-ischemic (n = 183).The ESC 0/1 h hs-cTnI algorithm was applied for risk stratification. Diagnostic performance (sensitivity, specificity, NPV, PPV) was evaluated against clinical diagnosis. Prognostic value for 30-day and 180-day all-cause mortality and major adverse cardiovascular events (MACE) was assessed.

Sensitivity and NPV in the abnormal ECG group were both 100%, compared to 98.8% and 99.5% in the normal ECG group. Specificity was significantly lower in patients with ischemic ECG changes (81.2%) than in the normal ECG group (91.6%, P < 0.001). Subgroup analysis showed slightly lower sensitivity in women (95.5%), patients with pain onset ≤3 h (97.9%), and those aged ≤65 years (98.1%) within the normal ECG group. The algorithm effectively stratified mortality risk in both groups but showed limited discrimination for MACE in the abnormal ECG group.

The ESC 0/1-h hs-cTnI algorithm provides excellent rule-out safety across all ECG presentations. Crucially, a lower specificity-driven primarily by the ischemic ECG phenotype-suggests a higher risk of false-positive rule-in in this subgroup. Clinicians should integrate ischemic ECG patterns with clinical history to interpret algorithm results. Additionally, vigilance for potential under-detection in specific normal-ECG subgroups (women, younger patients, early presenters) remains warranted.