Coronary Heart Disease High-Sensitivity Cardiac Troponin in the Distinction of Acute Myocardial Infarction From Acute Cardiac Noncoronary Artery Disease

Background—We hypothesized that high-sensitivity cardiac troponin (hs-cTn) and its early change are useful in distinguishing acute myocardial infarction (AMI) from acute cardiac noncoronary artery disease. Methods and Results—In a prospective, international multicenter study, hs-cTn was measured with 3 assays (hs-cTnT, Roche Diagnostics; hs-cTnI, Beckman-Coulter; hs-cTnI Siemens) in a blinded fashion at presentation and serially thereafter in 887 unselected patients with acute chest pain. Accuracy of the combination of presentation values with serial changes was compared against a final diagnosis adjudicated by 2 independent cardiologists. AMI was the adjudicated final diagnosis in 127 patients (15%); cardiac noncoronary artery disease, in 124 (14%). Patients with AMI had higher median presentation values of hs-cTnT (0.113 ␮g/L [interquartile range, 0.049 – 0.246 ␮g/L] versus 0.012 ␮g/L [interquartile range, 0.006 – 0.034 ␮g/L]; PϽ0.001) and higher absolute changes in hs-cTnT in the first hour (0.019 ␮g/L [interquartile range, 0.007– 0.067 ␮g/L] versus 0.001 ␮g/L [interquartile range, 0 – 0.003 ␮g/L]; PϽ0.001) than patients with cardiac noncoronary artery disease. Similar findings were obtained with the hs-cTnI assays. Adding changes of hs-cTn in the first hour to its presentation value yielded a diagnostic accuracy for AMI as quantified by the area under the receiver-operating characteristics curve of 0.94 for hs-cTnT (0.92 for both hs-cTnI assays). Algorithms using ST-elevation, presentation values, and changes in hs-cTn in the first hour accurately separated patients with AMI and those with cardiac noncoronary artery disease. These findings were confirmed when the final diagnosis was readjudicated with the use of hs-cTnT values and validated in an independent validation cohort. Conclusion—The combined use of hs-cTn at presentation and its early absolute change excellently discriminates between patients with AMI and those with cardiac noncoronary artery disease. A cute myocardial infarction (AMI) is a major cause of death and disability worldwide. Its rapid and accurate diagnosis is critical for the initiation of effective evidence-based medical management, including early revasculariza-tion, 1,2 but is still an unmet clinical need. Particularly challenging is distinguishing AMI from cardiac noncoronary artery diseases (CNCDs) such as hypertensive urgency/ emergency, myocarditis, pericarditis, Takotsubo cardiomyop-athy (TTC), acute heart failure, and cardiac arrhythmia. ECG and cardiac troponin (cTn) form the diagnostic cornerstones of clinical assessment. 3 ECG alone is often insufficient to diagnose AMI because significant ECG changes are absent in numerous AMI patients and because ST-segment deviation may be observed in multiple other cardiac and noncardiac conditions. 3,4 Cardiac troponins, structural proteins unique to …