Absolute and relative changes (delta) in troponin I for early diagnosis of myocardial infarction: Results of a prospective multicenter trial

Alan B. Storrow, Richard M. Nowak, Deborah B. Diercks, Adam J. Singer, Alan H B Wu, Erik Kulstad, Frank LoVecchio, Christian Fromm, Gary Headden, Tracie Potis, Christopher J. Hogan, Jon W. Schrock, Daniel P. Zelinski, Marna R. Greenberg, Robert H. Christenson, James C. Ritchie, Janna S. Chamberlin, Kurtis R. Bray, Daniel W. Rhodes, Deirdre TrainorPaula C. Southwick

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

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 0.03. ng/mL demonstrated significant diagnostic efficacy (AUC 0.96). For patients with TnI. <. 0.03. ng/mL and symptom onset. ≥. 8. h, 99.1% (NPV) were diagnosed with conditions other than MI. Absolute delta performed significantly better than relative delta at 1-3. h (AUC 0.84 vs 0.69), 3-6. h (0.85 vs 0.73), and 6-9. h (0.91 vs 0.79). Current recommendations propose ≥. 20% delta within 3-6. h; however, results were optimized using an absolute delta of 0.01 or 0.02. ng/mL. Sensitivity results for absolute delta at 1-3. h and 3-6. h (75.8%, 78.3%) were superior to relative delta (48.0%, 61.3%). NPV (rule out) was 99.6% when baseline TnI. <. 0.03. ng/mL and absolute delta TnI. <. 0.01. ng/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 3. h later, repeated at 6. h in patients when clinical suspicion remains high.

Original languageEnglish (US)
Pages (from-to)260-267
Number of pages8
JournalClinical Biochemistry
Volume48
Issue number4-5
DOIs
StatePublished - Mar 1 2015

Keywords

  • Acute coronary syndrome
  • Biomarker
  • Chest pain diagnosis
  • Myocardial infarction
  • Troponin

ASJC Scopus subject areas

  • Clinical Biochemistry

Fingerprint Dive into the research topics of 'Absolute and relative changes (delta) in troponin I for early diagnosis of myocardial infarction: Results of a prospective multicenter trial'. Together they form a unique fingerprint.

Cite this