Rapid Evaluation of Acute Myocardial Infarction in a United States Population Using High Sensitivity Cardiac Troponin T and a European Society of Cardiology 0/1-Hour Algorithm Guideline

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Conference Proceeding

Publication Date


Publication Title

Acad Emerg Med


Background: A baseline and 1 hour rule-in/rule-out acute myocardial infarction (AMI) algorithm using high sensitivity cardiac troponin T (hs-cTnT) measurements has been reported and validated in several non-United States (US) studies and is recommended in the 2015 European Society of Cardiology (ESC) NSTEMI guidelines. There is no similar approach incorporated in any current US organizational NSTEMI guidelines. The purpose of this study was to apply the ESC baseline and 1 hour algorithm to a US Emergency Department (ED) population presenting with suspected acute coronary syndrome (ACS) to determine its clinical usefulness.

Methods: Patients presenting with any symptoms suspicious of ACS at a single US tertiary care urban center were enrolled. Baseline (within 60 minutes of triage ECG) and 60 minute blood samples were obtained for blinded independent hs-cTnT (Roche) measurements. AMI diagnosis was independently adjudicated by 2 physicians after reviewing all available 30 day clinical data and the hospitals serial cardiac troponin I (Siemens) levels over 3 hours in accordance with the 3rd Universal Definition of AMI.

Results: Of the 569 enrolled subjects 44 (7.7%) had AMI. Analyzing the baseline and 1 hour ESC algorithm in the 543 patients with these hs-cTnT values available resulted in 312 (57.5%) assigned to the rule-out zone (0 hour < 12 and 1 hour delta < 3 ng/L), 162 (29.8%) to the observation group and 69 (12.7%) to the rule-in zone (0 hour > 52 or 1 hour delta â%o¥ 5 ng/L). The negative predicted value (NPV) and sensitivity for AMI were 99.4% and 95.5% (2 AMIs (0.63%), importantly both type 2, were missed in the rule-out zone while the rule-in zone positive predictive value (PPV) and specificity for AMI were 42.0% and 92.0%. Our results were very similar to those reported in the TRAPID-AMI study (ESC guidelines) for the rule-out zone (NPV and sensitivity 99.1% and 96.7% [7 AMIs (0.05%) were missed) but dissimilar for the rule-in zone (PPV and specificity 77.2% and 96.1%).

Conclusion: In our opinion the most important aspect of the ESC baseline and 1 hour recommendations for clinicians is the rapid rule-out of AMI in the large number of ED patients with suspected ACS. For this purpose the rule-out zone of these ESC guidelines, when applied to a US population, has very similar NPVs and sensitivities and so could be used in like fashion. However further multicenter US ED studies are needed to validate our findings.



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