Abstract 16456: Cardiac Troponin Levels Do Not Change in Response to Exercise Stress Testing
Introduction: Exercise stress testing is commonly used to evaluate chest pain patients in the emergency department (ED). However, sensitivity is suboptimal, and the imaging component is both resource-intensive and may result in radiation exposure. A biomarker-based evaluation component for an exercise stress test would have several advantages.
Hypothesis: We hypothesized that high-sensitivity troponin T (hsTnT) would increase from pre-exercise to post-exercise among patients undergoing exercise stress testing. We further hypothesized that these “stress-delta” values could differentiate patients with myocardial ischemia from those without.
Methods: We prospectively collected demographic and clinical data, including stress test results, from 186 patients who presented to the ED with symptoms of acute coronary syndrome, had ruled out for myocardial infarction by serial contemporary TnT assays and electrocardiography, and were scheduled for exercise echocardiography. Plasma HsTnT (Roche Diagnostics) concentrations were determined at baseline (pre-exercise test) and 2 hours post-stress test. Absolute and relative changes between baseline and post-stress hsTnT values were calculated for patients with and without evidence of myocardial ischemia. All stress tests were interpreted by board-certified cardiologists blinded to stress-delta hsTNT results.
Results: The median age of participants was 50 years, 45.2% were men and 41.4% were African American. Eleven patients (5.9%) had myocardial ischemia on stress echocardiography. The median baseline, 2-hour, and absolute and relative stress delta hsTnT values are shown in Table 1.
Conclusions: There was no evidence of change in hsTnT values in response to exercise stress testing, regardless of the presence of myocardial ischemia by echocardiographic imaging. Future research should determine if stress-delta values of other biomarkers can identify myocardial ischemia.
Author Disclosures: A. Limkakeng: Research Grant; Significant; Roche Diagnostics, Abbott Laboratories, Siemens Healthcare Diagnostics, The Medicines Company. Other Research Support; Significant; Roche Diagnostics, Abbott Laboratories, Siemens Healthcare Diagnostics, The Medicines Company. W. Drake: Other Research Support; Significant; Roche Diagnostics Operations, Inc. Abbott Laboratories The Medicines Company; and Siemens Healthcare Diagnostics, Abbott Laboratories, Siemens Healthcare Diagnostics, The Medicines Company. Y. Lokhnygina: Other Research Support; Modest; Roche Diagnostics, Inc. L. Newby: Research Grant; Significant; Bristol Myers Squibb, Glaxo SmithKline (GSK), Murdock Study. Consultant/Advisory Board; Modest; AstraZeneca, Daiichi-Sankyo, Genentech, Novartis, Roche Diagnostics, Jansen Pharmacueticals, Inc, Navigant, DSI-Lilly, BioKier, Phillips, Cubist/INC Research, CardioDx.
- © 2014 by American Heart Association, Inc.