High sensitivity troponin outperforms contemporary assays in predicting major adverse cardiac events up to two years in patients with chest pain.

BACKGROUND

Previous studies have shown a risk of subsequent major adverse cardiovascular events (MACEs) in patients with suspected acute coronary syndromes (ACSs) and elevated cardiac troponin. The aim of this study was to compare prognostic utility of high-sensitivity troponin with contemporary troponin assays in such patients.

METHODS

In total, 332 patients with suspected ACS were investigated between November 2006 and April 2007; all were followed for two years. Blood samples were analysed to compare Roche Elecsys high-sensitivity troponin T (hsTnT), Abbott Architect troponin I 3rd generation (TnI 3) and Roche Elecsys troponin T (TnT), for the prediction of MACE (composite of cardiovascular death, non-fatal myocardial infarction and revascularization).

RESULTS

Sixty-eight patients (20.5%) experienced MACE between discharge and two years. Receiver operating characteristic (ROC) curve derived area under the ROC curve (95% confidence intervals) for baseline hsTnT were 0.70 (0.63-0.76), TnI 3 0.66 (0.59-0.73) and TnT 0.61 (0.53-0.69). hsTnT (P = 0.001) was superior to TnT and TnI 3 trended (P = 0.094) to superiority but were equivalent to each other. hsTnT best stratified patients with cumulative event rates for two-year MACE of 35.6% for levels ≥99th percentile, 17.9% for levels between the limit of detection (LOD) and 99th percentile and 5.4% for levels <LOD compared with TnI 3: 33.0%, 31.1% and 10.9%, respectively. TnT had MACE rates of 36.7% when ≥99th percentile and 15.4% when <99th percentile (=LOD).

CONCLUSIONS

hsTnT outperformed contemporary TnI and TnT assays for the prediction of MACE at two years. Those with levels below the LOD for hsTnT identified a group of patients at very low risk for adverse events.