Absolute and Relative Changes (Delta) in Troponin I for Early Diagnosis of Myocardial Infarction: Results of a Prospective Multicenter Trial.
Publication/Presentation Date
3-1-2015
Abstract
OBJECTIVES: We investigated absolute and relative cardiac troponin I (TnI) delta changes, optimal sampling protocols, and decision thresholds for early diagnosis of myocardial infarction (MI). Serial cardiac biomarker values demonstrating a rise and/or fall define MI diagnosis; however the magnitude of change, timing, and diagnostic accuracy of absolute versus relative (percentage) deltas remains unsettled.
METHODS: We prospectively measured TnI (AccuTnI+3™, Beckman Coulter) at serial time intervals in 1929 subjects with chest pain or equivalent symptoms of acute coronary syndrome at 14 medical centers. Diagnosis was adjudicated by an independent central committee.
RESULTS: Elevated TnI above a threshold of 0.03ng/mL demonstrated significant diagnostic efficacy (AUC 0.96). For patients with TnI<0.03ng/mL and symptom onset≥8h, 99.1% (NPV) were diagnosed with conditions other than MI. Absolute delta performed significantly better than relative delta at 1-3h (AUC 0.84 vs 0.69), 3-6h (0.85 vs 0.73), and 6-9h (0.91 vs 0.79). Current recommendations propose ≥20% delta within 3-6h; however, results were optimized using an absolute delta of 0.01 or 0.02ng/mL. Sensitivity results for absolute delta at 1-3h and 3-6h (75.8%, 78.3%) were superior to relative delta (48.0%, 61.3%). NPV (rule out) was 99.6% when baseline TnI<0.03ng/mL and absolute delta TnI<0.01ng/mL.
CONCLUSIONS: Absolute delta performed significantly better than relative delta at all time intervals. Baseline TnI and absolute delta may be used in conjunction to estimate probability of MI. Consensus recommendations are supported for sampling on admission and 3h later, repeated at 6h in patients when clinical suspicion remains high.
Volume
48
Issue
4-5
First Page
260
Last Page
267
ISSN
1873-2933
Published In/Presented At
Storrow, A. B., Nowak, R. M., Diercks, D. B., Singer, A. J., Wu, A. B., Kulstad, E., & ... Southwick, P. C. (2014). Absolute and Relative Changes (Delta) in Troponin I for Early Diagnosis of Myocardial Infarction: Results of a Prospective Multicenter Trial. Clinical Biochemistry,
Disciplines
Emergency Medicine | Other Medicine and Health Sciences
PubMedID
25261587
LVHN link
http://search.ebscohost.com/login.aspx?direct=true&db=mnh&AN=25261587&site=ehost-live&scope=site
Department(s)
Department of Emergency Medicine, Department of Emergency Medicine Faculty
Document Type
Article