Third Universal Definition of Myocardial Infarction

Abstract

The term acute myocardial infarction (MI) should be used when there is evidence of myocardial necrosis in a clinical setting consistent with acute myocardial ischemia. Under these conditions any one of the following criteria meets the diagnosis for MI: ● Detection of a rise and/or fall of cardiac biomarker values [preferably cardiac troponin (cTn)] with at least one value above the 99th percentile upper reference limit (URL) and with at least one of the following: y Symptoms of ischemia. y New or presumed new significant ST-segment–T wave (ST–T) changes or new left bundle branch block (LBBB). y Development of pathological Q waves in the ECG. y Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality. y Identification of an intracoronary thrombus by angiography or autopsy. ● Cardiac death with symptoms suggestive of myocardial ischemia and presumed new ischemic ECG changes or new LBBB, but death occurred before cardiac biomarkers were obtained, or before cardiac biomarker values would be increased. ● Percutaneous coronary intervention (PCI) related MI is arbitrarily defined by elevation of cTn values (5 99th percentile URL) in patients with normal baseline values (99th percentile URL) or a rise of cTn values 20% if the baseline values are elevated and are stable or falling. In addition, either (i) symptoms suggestive of myocardial ischemia or (ii) new ischemic ECG changes or (iii) angiographic findings consistent with a procedural complication or (iv) imaging demonstration of new loss of viable myocardium or new regional wall motion abnormality are required. ● Stent thrombosis associated with MI when detected by coronary angiography or autopsy in the setting of myocardial ischemia and with a rise and/or fall of cardiac biomarker values with at least one value above the 99th percentile URL. ● Coronary artery bypass grafting (CABG) related MI is arbitrarily defined by elevation of cardiac biomarker values (10 99th percentile URL) in patients with normal baseline cTn values (99th percentile URL). In addition, either (i) new pathological Q waves or new LBBB, or (ii) angiographic documented new graft or new native coronary artery occlusion, or (iii) imaging evidence of new loss of viable myocardium or new regional wall motion abnormality. Criteria for prior myocardial infarction Any one of the following criteria meets the diagnosis for prior MI: ● Pathological Q waves with or without symptoms in the absence of non-ischemic causes. ● Imaging evidence of a region of loss of viable myocardium that is thinned and fails to contract, in the absence of a non-ischemic cause. ● Pathological findings of a prior MI

Role of Admission Troponin‐T and Serial Troponin‐T Testing in Predicting Outcomes in Severe Sepsis and Septic Shock

“…Ischemia is often difficult to identify in critically ill patients, adding to uncertainty regarding the need for serial measurement of TnT 33. This study identified a significant delta TnT in one fifth of patients with elevated admission TnT, yet this carried no incremental prognostic value.…”

Trends in Use of Biomarker Protocols for the Evaluation of Possible Myocardial Infarction

“…There has been substantial evolution in the use of cardiac biomarkers for diagnosis of AMI 2, 3, 8, 9. To shorten the time to exclusion of AMI, different combinations of markers have been utilized, including various combinations of cTn, CK‐MB, and myoglobin.…”

“…To shorten the time to exclusion of AMI, different combinations of markers have been utilized, including various combinations of cTn, CK‐MB, and myoglobin. Because of its superior sensitivity and diagnostic accuracy, cTn is considered the gold‐standard biomarker for risk stratification and diagnosis of AMI 2, 3, 8, 9, 10, 11, 12. The recommendation to use cTn as a sole biomarker has remained consistent through the first, second, and third universal definitions of myocardial infarction published in 2000, 2007, and 2012, respectively.…”

“…The second universal definition of myocardial infarction consensus document,3 published in 2007, recommended specific criteria for diagnosis of AMI, in which cTnI or cTnT was the preferred cardiac biomarker with sample measurement at time 0 (presentation), followed by repeat sampling 6 to 9 hours later, and included a rise or fall of cTn with at least 1 value exceeding the 99th percentile reference range cut point for AMI diagnosis, using a recommended optimal assay precision at the 99th percentile of <10% coefficient of variation 3. Importantly, use of the 99th percentile as the cut‐off value increases the frequency of AMI diagnosis, has been associated with improved outcomes, and is championed as a Laboratory Medicine Best Practice 4, 5, 6.…”

“…Importantly, use of the 99th percentile as the cut‐off value increases the frequency of AMI diagnosis, has been associated with improved outcomes, and is championed as a Laboratory Medicine Best Practice 4, 5, 6. Guidelines were updated in 2012, shortening the marker sampling interval to 3 to 6 hours, reflecting the improved cTn assay sensitivity 3. In this analysis, we assessed biomarker strategies used by US hospitals to evaluate suspected AMI patients, identified changes in strategy over time, and compared findings with the current guidelines.…”