Predicting Acute Myocardial Infarction with a Single Blood Draw.

Abstract

BACKGROUND:

We desired to determine cardiac troponin (cTn) concentrations necessary to achieve a positive predictive value (PPV) of ≥75% for acute myocardial infarction (AMI) to justify immediate admission of patients to a monitored unit and, in general, early coronary angiography.

METHODS:

In a prospective multicenter diagnostic study enrolling patients presenting to the emergency department with symptoms suggestive of AMI, final diagnoses were adjudicated by 2 independent cardiologists based on clinical information including cardiac imaging. cTn concentrations were measured using 5 different sensitive and high-sensitivity cTn (hs-cTn) assays in a blinded fashion at presentation and serially thereafter. The diagnostic end point was PPV for rule-in of AMI of initial cTn concentrations alone and in combination with early changes.

RESULTS:

Among 3828 patients, 616 (16%) had an AMI. At presentation, 7% to 14% of patients had cTnT/I concentrations associated with a PPV of ≥75%. Adding absolute or relative changes did not significantly further increase the PPV. PPVs increased from 46.5% (95% CI, 43.6-49.4) for hs-cTnT at presentation >14 ng/L to 78.9% (95% CI, 74.7-82.5) for >52 ng/L (P < 0.001), whereas PPVs in higher hs-cTnT strata remained largely unchanged [e.g., 82.4% (95% CI, 77.5-86.7) for >80 ng/L vs 83.9% (95% CI, 76.0-90.1) for >200 ng/L (P = 0.72)]. The addition of early changes in hs-cTnT further increased the PPV up to 60 ng/L, but not for higher concentrations.

CONCLUSIONS:

Serial sampling does not seem necessary for predicting AMI and concurrent decision-making in about 10% of patients, as it only marginally increases the PPV for AMI and not in a statistically or clinically significant way.

CLINICALTRIALSGOV IDENTIFIER:

NCT00470587.

• Authors: Jasper Boeddinghaus, Thomas Nestelberger, Patrick Badertscher, Raphael Twerenbold, Brigitte Fitze, Desiree Wussler, Ivo Strebel, Maria Rubini Giménez, Karin Wildi, Christian Puelacher, Jeanne du Fay de Lavallaz, Loris Oehen, Joan Walter, Òscar Miró, F Javier Martin-Sanchez, Beata Morawiec, Eliska Potlukova, Dagmar I Keller, Tobias Reichlin, Christian Mueller, APACE Investigators
• Journal: Clinical chemistry (Clin Chem) Vol. 65 Issue 3 Pg. 437-450 (03 2019) ISSN: 1530-8561 [Electronic] England
• PMID: 30626633 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 American Association for Clinical Chemistry.

Chemical References

• Biomarkers
• Troponin I
• Troponin T

Topics

• Acute Disease
• Aged
• Aged, 80 and over
• Biomarkers (blood)
• Blood Chemical Analysis (methods)
• Female
• Humans
• Male
• Middle Aged
• Myocardial Infarction (diagnosis)
• Predictive Value of Tests
• Prospective Studies
• Troponin I (blood)
• Troponin T (blood)