Elements of the fourth universal definition used in the diagnosis of acute myocardial infarction

In the era of high-sensitivity cardiac troponin (hs-cTn) assays, a high proportion of individuals coming to the emergency department (ED) suspected of having an acute myocardial infarction (AMI) will generate a reportable troponin concentration. This results in greater scrutiny in clinical context to differentiate from myocardial injury to prevent inappropriate treatment plans, hospitalizations, and cost to the healthcare system compared to contemporary troponin assays. This study evaluates the use of ischemic symptoms, ECG changes, abnormal angiography/imaging results, which adjudicating physicians use in determining the diagnosis of AMI, as per the 4 th universal definition of MI. Patients who presented to the ED and were evaluated for possible AMI were included in this study. After completion of patient care, a diagnosis of AMI was independently adjudicated by 2 cardiologists and 1 emergency medicine physician. This adjudication process determined that patient symptomatology was the most prevalent factor, influencing the adjudication process in 95.2% of AMI diagnoses. Electrocardiography supported AMI diagnosis in 35.7% of patients, with significantly more utility in diagnosing Type 2 AMI. Of the 4 factors, coronary angiography was less performed (10.5%) yet had a high positive rate, being used as one of the confirming factors in 59.5% of all AMI patients. Coronary angiography had greater utility in diagnosing Type 1 AMI. Imaging including echocardiography and nuclear imaging was performed in 30.1% of all patients but was a factor in diagnosing AMI in 26.2% AMI patients. This study emphasizes that symptomology remains critical in diagnosing AMI.