Direct Comparison of 4 Very Early Rule-Out Strategies for Acute Myocardial Infarction Using High-Sensitivity Cardiac Troponin I

Circulation. 2017 Apr 25;135(17):1597-1611. doi: 10.1161/CIRCULATIONAHA.116.025661. Epub 2017 Mar 10.

Abstract

Background: Four strategies for very early rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I (hs-cTnI) have been identified. It remains unclear which strategy is most attractive for clinical application.

Methods: We prospectively enrolled unselected patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction. The final diagnosis was adjudicated by 2 independent cardiologists. Hs-cTnI levels were measured at presentation and after 1 hour in a blinded fashion. We directly compared all 4 hs-cTnI-based rule-out strategies: limit of detection (LOD, hs-cTnI<2 ng/L), single cutoff (hs-cTnI<5 ng/L), 1-hour algorithm (hs-cTnI<5 ng/L and 1-hour change<2 ng/L), and the 0/1-hour algorithm recommended in the European Society of Cardiology guideline combining LOD and 1-hour algorithm.

Results: Among 2828 enrolled patients, acute myocardial infarction was the final diagnosis in 451 (16%) patients. The LOD approach ruled out 453 patients (16%) with a sensitivity of 100% (95% confidence interval [CI], 99.2%-100%), the single cutoff 1516 patients (54%) with a sensitivity of 97.1% (95% CI, 95.1%-98.3%), the 1-hour algorithm 1459 patients (52%) with a sensitivity of 98.4% (95% CI, 96.8%-99.2%), and the 0/1-hour algorithm 1463 patients (52%) with a sensitivity of 98.4% (95% CI, 96.8%-99.2%). Predefined subgroup analysis in early presenters (≤2 hours) revealed significantly lower sensitivity (94.2%, interaction P=0.03) of the single cutoff, but not the other strategies. Two-year survival was 100% with LOD and 98.1% with the other strategies (P<0.01 for LOD versus each of the other strategies).

Conclusions: All 4 rule-out strategies balance effectiveness and safety equally well. The single cutoff should not be applied in early presenters, whereas the 3 other strategies seem to perform well in this challenging subgroup.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Keywords: diagnosis; myocardial infarction; rule-out strategies.

Publication types

  • Comparative Study
  • Multicenter Study

MeSH terms

  • Acute Coronary Syndrome / blood
  • Acute Coronary Syndrome / diagnosis*
  • Acute Coronary Syndrome / mortality
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Algorithms
  • Biomarkers / blood
  • Decision Support Techniques*
  • Electrocardiography
  • Europe
  • Female
  • Health Status
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Myocardial Infarction / blood
  • Myocardial Infarction / diagnosis*
  • Myocardial Infarction / mortality
  • Predictive Value of Tests
  • Prognosis
  • Prospective Studies
  • Risk Assessment
  • Risk Factors
  • Sex Factors
  • Time Factors
  • Troponin I / blood*
  • Up-Regulation

Substances

  • Biomarkers
  • Troponin I

Associated data

  • ClinicalTrials.gov/NCT00470587