Diagnostic accuracy of a point-of-care troponin I assay for acute myocardial infarction within 3 hours after presentation in early presenters to the emergency department with chest pain.

Abstract

BACKGROUND:

Guidelines recommend that serial cardiac marker testing to rule out acute myocardial infarction (AMI) be performed for 8 to 12 hours after symptom onset. We aim to determine the diagnostic accuracy of a contemporary point-of-care (POC) troponin I (TnI) assay within 3 hours for patients presenting within 8 hours of symptom onset.

METHODS:

The MIDAS study collected blood from patients presenting with suspected acute coronary syndrome at presentation and at 90 minutes, 3 hours, and 6 hours in whom the emergency physician planned an objective cardiac ischemia evaluation. Criterion standard diagnoses were adjudicated by experienced clinicians using all available medical records per American Heart Association/American College of Cardiology criteria. Reviewers were blinded to the investigational marker, Cardio3 TnI POC. The Cardio3 TnI reference value was defined as >0.05 ng/mL. Measures of diagnostic accuracy are presented with 95% CI.

RESULTS:

A total of 858 of 1107 patients met the inclusion criteria. The study cohort had 476 men (55.5%) with median age of 57.0 years (interquartile range 48.0-67.0 years). Median time from symptom onset to initial blood draw was 3.9 hours (interquartile range 2.7-5.2 hours). Acute myocardial infarction was diagnosed in 82 patients (9.6%). The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio over 3 hours were 84.1, 93.4, 12.8, and 0.17, respectively. There was no significant improvement in diagnostic accuracy associated with adding 6-hour serial testing to the 3-hour sample.

CONCLUSION:

In suspected patients with acute coronary syndrome presenting to the emergency department within 8 hours of symptom onset, 3 hours of serial testing with the Cardio3 TnI POC platform provides similar diagnostic accuracy for AMI as longer periods.

• Authors: Deborah B Diercks, W Frank Peacock 4th, Judd E Hollander, Adam J Singer, Robert Birkhahn, Nathan Shapiro, Ted Glynn, Richard Nowack, Basmah Safdar, Chadwick D Miller, Elizabeth Lewandrowski, John T Nagurney
• Journal: American heart journal (Am Heart J) Vol. 163 Issue 1 Pg. 74-80.e4 (Jan 2012) ISSN: 1097-6744 [Electronic] United States
• PMID: 22172439 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Mosby, Inc. All rights reserved.

Chemical References

• Biomarkers
• Troponin I

Topics

• Aged
• Angina Pectoris (etiology)
• Biomarkers (blood)
• Cohort Studies
• Emergency Service, Hospital (standards)
• Female
• Humans
• Male
• Middle Aged
• Myocardial Infarction (blood, complications, diagnosis)
• Point-of-Care Systems (standards)
• Predictive Value of Tests
• Prospective Studies
• Troponin I (blood)
• United States