Abstract 9507: Noise vs. Signal: The Clinical Implications of A High Sensitivity Troponin Assay in the Evaluation of Possible Acute Coronary Syndrome
Objectives: To evaluate the real-world impact of a switch from conventional troponin I (cTnI) measurement to a high-sensitivity (hsTnI) assay in patients with acute coronary syndromes (ACS).
Methods: This was a retrospective analysis of ACS cases from a single hospital system in the 3 months before and after a troponin assay switch. Outcomes included admitting diagnosis, initial treatment and diagnostic testing, need for coronary artery intervention (i.e., stent placement), in-hospital events, and final discharge diagnosis. Descriptive statistics and univariate comparisons by assay group were performed.
Results: 783 ACS cases (mean age 60.9 yrs; 52.9% male; 77.7% black) were identified, 330 (42.1%) before and 453 (57.9%) after the assay change with no difference in demographics by assay period. An admitting diagnosis of NSTEMI was more common after the assay change (43.0% vs. 70.4%; p < 0.001) as was the proportion with a positive troponin (32.1% vs. 71.3%; p < 0.001). While aspirin (92.4% vs. 91.4%; p = 0.79), beta-blocker (76.1% vs. 80.8%; p = 0.09) and clopidogrel (50.9% vs. 46.6%; p = 0.25) use was similar, anticoagulants were used more often after the assay change (45.8% vs. 56.3%; p = 0.004). Echocardiography was also more common (39.7% vs. 47.0%; p = 0.05), but cardiac catheterization was less frequent (53.6% vs. 41.7%; p = 0.003) with no difference in the proportion who underwent stent placement (52.4% vs. 50.0%; p = 0.72). In-hospital event rates (Table) were equivalent. At discharge, diagnosis of NSTEMI was more likely post-assay change (27.9% vs. 36.6%; p = 0.011).
Conclusions: After the switch to a hsTnI assay, more ACS patients had a positive test result and a greater proportion were diagnosed with NSTEMI at admission. Despite this, cardiac catheterization was used less frequently and coronary artery intervention as well as in-hospital event rates were flat, highlighting the uncertainty that surrounds a positive troponin in an era of high-sensitivity assays.
- © 2012 by American Heart Association, Inc.