High-Sensitivity Cardiac Troponin T to OPtimize Chest Pain Risk Stratification

Approximately 8 million - 10 million patients complaining of chest pain present to an Emergency Department (ED) annually in the United States. To avoid missing the diagnosis of acute coronary syndrome (ACS), physicians use a liberal testing strategy. Thus, >50% of ED patients with acute chest pain are hospitalized for a comprehensive cardiac evaluation (serial cardiac biomarkers and stress testing or angiography). However, <10% of these patients are ultimately diagnosed with ACS, and this pervasive over-triage costs an estimated $10 billion - $13 billion annually. Current care patterns for acute chest pain fail to focus health system resources, such as hospitalization and stress testing, on patients most likely to benefit.

It has demonstrated that an accelerated diagnostic protocol (ADP), called the HEART Pathway, which utilizes a clinical decision aid (the HEART score) and serial Cardiac Troponin (cTn) measures are sensitive for ACS (>99%) and can substantially reduce hospitalizations, stress testing, and cost compared to usual care. The HEART Pathway uses contemporary serial cTn measurements at 0 and 3 hours to exclude index myocardial infarction (MI) and relies on clinical features (history, ECG, age, and risk factors) to identify patients likely to have downstream events. However, the HEART Pathway has limitations: a) It identifies only 20 - 40% of patients for early discharge and b) it was developed before high-sensitivity cTn assays became available. Able to detect MI earlier and with greater accuracy than contemporary assays, hs-cTn assays have the potential to be integrated into decision aids to improve chest pain risk stratification. In the near future, hs-cTn assays will replace contemporary assays in the United States.