One-hour Rule-in and Rule-out of Acute Myocardial Infarction Using High-sensitivity Cardiac Troponin I

• Published in: The American journal of medicine Vol. 128; no. 8; pp. 861 - 870.e4
• Main Authors: Rubini Gimenez, Maria, MD, Twerenbold, Raphael, MD, Jaeger, Cedric, MD, Schindler, Christian, PhD, Puelacher, Christian, MD, Wildi, Karin, MD, Reichlin, Tobias, MD, Haaf, Philip, MD, Merk, Salome, MD, Honegger, Ursina, MS, Wagener, Max, MD, Druey, Sophie, MD, Schumacher, Carmela, MD, Krivoshei, Lian, MD, Hillinger, Petra, MD, Herrmann, Thomas, MD, Campodarve, Isabel, MD, Rentsch, Katharina, PhD, Bassetti, Stefano, MD, Osswald, Stefan, MD, Mueller, Christian, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2015; Elsevier Sequoia S.A
• Subjects: Accurate rule-in; Acute myocardial infarction; Aged; Aged, 80 and over; Algorithms; Biomarkers - blood; Chest Pain - etiology; Electrocardiography; Follow-Up Studies; Heart attacks; hs-cTn; Humans; Internal Medicine; Medical diagnosis; Middle Aged; Myocardial Infarction - diagnosis; Myocardial Infarction - mortality; Predictive Value of Tests; Prospective Studies; Proteins; Safe rule-out; Time Factors; Troponin I - blood; Safe rule-out; hs-cTn; Accurate rule-in; Acute myocardial infarction
• ISSN: 0002-9343; 1555-7162
• DOI: 10.1016/j.amjmed.2015.01.046

Abstract 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.