Outcomes associated with small changes in normal-range cardiac markers.

Introduction: Troponin concentrations rising above an institutional cutpoint are used to define acute myocardial necrosis, yet it is uncertain what outcomes are associated with fluctuations in troponin that do not exceed this level. We evaluate the association between troponin fluctuations below an institutional upper limit of normal and acute coronary syndrome (ACS).

Materials And Methods: This was a post hoc analysis of the Internet tracking registry of ACS (i*trACS), which describes patients presenting to emergency departments (EDs) with suspected ACS across the spectrum of risk.