Early Rule-out of Acute Coronary Syndrome Using Undetectable Levels of High Sensitivity Troponin T

Aims: To examine whether undetectable high sensitivity troponin T (hsTnT) can be used to safely rule out non-ST-elevation acute coronary syndrome (NSTE-ACS) (using the limit of detection (LOD) as the cut-off) and to compare this strategy to serial hsTnT and the use of combined hsTnT and copeptin.

Methods: In this prospective observational study, 478 patients presenting with chest pain were consecutively included. A combined primary endpoint of ACS, non-elective revascularization and/or death of all causes was used. The follow-up period was 60 days.

Results: NSTE-ACS was diagnosed in 107 (22%) patients during hospital stay. Undetectable hsTnT at admission ruled out NSTE-ACS with a negative predictive value of 94% (95% confidence interval (CI): 88-97) giving a sensitivity of 0.90 (95% CI: 0.80-0.95) versus 0.78 (95% CI: 0.66-0.87) for serial hsTnT testing, p=0.008. The combination of hsTnT and copeptin analysed at admission resulted in a sensitivity of 0.83 (95% CI: 0.74-0.89), p=0.07 for comparison with undetectable hsTnT.

Conclusion: A single hsTnT test at presentation, using the LOD as the cut-off, appears to be a safe and time-saving strategy to rule out NSTE-ACS. Further, undetectable levels of hsTnT were associated with an excellent prognosis and none of the patients with undetectable hsTnT were diagnosed with NSTEMI. Together with ECG and clinical assessment this biomarker strategy might permit outpatient treatment of almost one third of the patients we currently admit for observation.