One-hour rule-in and rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I

Am J Med. 2015 Aug;128(8):861-870.e4. doi: 10.1016/j.amjmed.2015.01.046. Epub 2015 Mar 31.


Objective: We aimed to prospectively derive and validate a novel 1h-algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for early rule-out and rule-in of acute myocardial infarction.

Methods: We performed a prospective multicenter diagnostic study enrolling 1811 patients with suspected acute myocardial infarction. The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data, and serial measurements of hs-cTnT (but not hs-cTnI). The hs-cTnI 1h-algorithm, incorporating measurements performed at baseline and absolute changes within 1 hour, was derived in a randomly selected sample of 906 patients (derivation cohort), and then validated in the remaining 905 patients (validation cohort).

Results: Acute myocardial infarction was the final diagnosis in 18% of patients. After applying the hs-cTnI 1h-algorithm developed in the derivation cohort to the validation cohort, 50.5% of patients could be classified as "rule-out," 19% as "rule-in," 30.5% as "observe." In the validation cohort, the negative predictive value for acute myocardial infarction in the "rule-out" zone was 99.6% (95% confidence interval, 98.4%-100%), and the positive predictive value for acute myocardial infarction in the "rule-in" zone was 73.9% (95% confidence interval, 66.7%-80.2%). Negative predictive value of the 1h-algorithm was higher compared with the classical dichotomous interpretation of hs-cTnI and to the standard of care combining hs-cTnI with the electrocardiogram (both P < .001). Positive predictive value also was higher compared with the standard of care (P < .001).

Conclusion: Using a simple algorithm incorporating baseline hs-cTnI values and the absolute change within the first hour allows safe rule-out as well as accurate rule-in of acute myocardial infarction in 70% of patients presenting with suspected acute myocardial infarction.

Trial registration: NCT00470587.

Keywords: Accurate rule-in; Acute myocardial infarction; Safe rule-out; hs-cTn.

Publication types

  • Multicenter Study
  • Observational Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Algorithms
  • Biomarkers / blood
  • Chest Pain / etiology
  • Electrocardiography
  • Follow-Up Studies
  • Humans
  • Middle Aged
  • Myocardial Infarction / diagnosis*
  • Myocardial Infarction / mortality
  • Predictive Value of Tests
  • Prospective Studies
  • Time Factors
  • Troponin I / blood*


  • Biomarkers
  • Troponin I

Associated data