Novel Criteria for the Observe-Zone of the ESC 0/1h-hs-cTnT Algorithm
Authors: Pedro Lopez-Ayala, Thomas Nestelberger, Jasper Boeddinghaus, Luca Koechlin, Paul David Ratmann, Ivo Strebel, Juliane Gehrke, Severin Meier, Joan Walter, Maria Rubini Gimenez, Eugenio Mutschler, Òscar Miró, Beatriz López-Barbeito, Francisco Javier Martín-Sánchez, Esther Rodríguez-Adrada, Dagmar I. Keller, L. Kristin Newby, Raphael Twerenbold, Evangelos Giannitsis, Bertil Lindahl, Christian Mueller, Tobias Zimmermann, Hadrien Schoepfer, Tania Coscia, Valentina Troester, Tobias Reichlin, Marina Kaeslin, Michael Christ, Mario Meier, Patrick Badertscher, Christian Puelacher, Jeanne du Fay de Lavallaz, Eliska Potlukova, Damian Kawecki, Nicolas Geigy, Katharina Rentsch, Samyut Shrestha, Beata Morawiec, Piotr Munzk, Tobias Breidthardt, Michael Freese, Gemma Martinez-Nadal, Carolina Fuenzalida, Sofia Calderón, Esther Rodriguez Adrada, Eva Ganovská, Jiri Parenica, Arnold von Eckardstein, Isabel Campodarve, Joachim Gea, James Mccord, Richard Nowak, Richard Body, Christopher R. deFilippi, Robert H. Christenson, Mauro Panteghini, Mario Plebani, Franck Verschuren, John French, Silvia Weiser, Tomas Jernberg
Journal: Circulation (2021)

Background: The non–ST-segment–elevation myocardial infarction (NSTEMI) guidelines of the European Society of Cardiology (ESC) recommend a 3h cardiac troponin determination in patients triaged to the observe-zone of the ESC 0/1h-algorithm; however, no specific cutoff for further triage is endorsed. Recently, a specific cutoff for 0/3h high-sensitivity cardiac troponin T (hs-cTnT) change (7 ng/L) was proposed, warranting external validation. Methods: Patients presenting with acute chest discomfort to the emergency department were prospectively enrolled into an international multicenter diagnostic study. Final diagnoses were centrally adjudicated by 2 independent cardiologists applying the fourth universal definition of myocardial infarction, on the basis of complete cardiac workup, cardiac imaging, and serial hs-cTnT. Hs-cTnT concentrations were measured at presentation, after 1 hour, and after 3 hours. The objective was to externally validate the proposed cutoff, and if necessary, derive and internally as well as externally validate novel 0/3h-criteria for the observe-zone of the ESC 0/1h-hs-cTnT-algorithm in an independent multicenter cohort. Results: Among 2076 eligible patients, application of the ESC 0/1h-hs-cTnT-algorithm triaged 1512 patients (72.8%) to either rule out or rule in NSTEMI, leaving 564 patients (27.2%) in the observe-zone (adjudicated NSTEMI prevalence, 120/564 patients, 21.3%). The suggested 0/3h-hs-cTnT-change of &lt;7 ng/L triaged 517 patients (91.7%) toward rule-out, resulting in a sensitivity of 33.3% (95% CI, 25.5–42.2), missing 80 patients with NSTEMI, and ≥7 ng/L triaged 47 patients toward rule-in (8.3%), resulting in a specificity of 98.4% (95% CI, 96.8–99.2). Novel derived 0/3h-criteria for the observe-zone patients ruled out NSTEMI with a 3h hs-cTnT concentration &lt;15 ng/L and a 0/3h-hs-cTnT absolute change &lt;4 ng/L, triaging 138 patients (25%) toward rule-out, resulting in a sensitivity of 99.2% (95% CI, 96.0–99.9), missing 1 patient with NSTEMI. A 0/3h-hs-cTnT absolute change ≥6 ng/L triaged 63 patients (11.2%) toward rule-in, resulting in a specificity of 98% (95% CI, 96.2–98.9) Thereby, the novel 0/3h-criteria reduced the number of patients in the observe zone by 36%s and the number of type 1 myocardial infarction by 50%. Findings were confirmed in both internal and external validation. Conclusions: A combination of a 3h-hs-cTnT concentration (&lt;15 ng/L) and a 0/3h absolute change (&lt;4 ng/L) is necessary to safely rule out NSTEMI in patients remaining in the observe-zone of the ESC 0/1h-hs-cTnT-algorithm. Registration: URL: https://clinicaltrials.gov ; Unique identifier: NCT00470587.