High Sensitivity Troponin Outperforms Conventional Assays in Estimating Significant Adverse Cardiac Occurrences Up to Two Years Ahead in Patients with Chest Pain- A Comparative Study

Abstract

Background- Prior research has indicated that patients with increased cardiac troponin and probable acute coronary syndromes (ACSs) are at risk for major adverse cardiovascular events (MACEs) in the future. This study compared the prognostic value of modern troponin assays with high-sensitivity troponin in these patients. Methods: Between November 2006 and April 2007, a total of 332 patients with suspected ACS were investigated; all patients were monitored for a period of two years. Abbott Architect troponin I, third generation (TnI 3) and Roche Elecsys high-sensitivity troponin T (hsTnT), as well as Roche Elecsys troponin T (TnT), were compared for their ability to predict MACE (composite of cardiovascular death, non-fatal myocardial infarction, and revascularization) using analysis of blood samples. Findings: Twenty-eight patients, or 20.5%, had a MACE between the time of discharge and two years. The 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), as determined by the receiver operating characteristic (ROC) curve. TnI 3 trended (P = 0.094) towards superiority but was equal to hsTnT (P = 0.001), which outperformed TnT. The patients who hsTnT best categorised had cumulative event rates for two-year MACE of 35.6% for levels that were above the 99th percentile, 17.9% for levels that fell between the 99th and limit of detection (LOD), and 5.4% for levels that predicted MACE at two years. Patients in this group had a very low risk of adverse outcomes since their hsTnT levels were below the lower limit of detection.