ST2 in Emergency Department Chest Pain Patients with Potential Acute Coronary Syndromes

Study objective The emergency department (ED) evaluation of potential acute coronary syndrome patients is limited by the initial sensitivity of cell injury biochemical markers. Increased ST2, a protein thought to participate in the response to cardiovascular injury, has been noted to be prognostic in patients with acute myocardial infarction. We hypothesize that ST2 would be increased at presentation in ED chest pain patients with myocardial ischemia, thus allowing for the early identification of acute myocardial infarction, acute coronary syndrome, and 30-day adverse cardiovascular events, with an area under the receiver operator characteristic curve (AUC) for each outcome of greater than 0.7. Methods Patients aged 25 years or older and presenting to the ED with chest pain prompting an ECG were prospectively enrolled. ST2 was measured at presentation. Main outcomes were acute myocardial infarction, acute coronary syndrome, and 30-day events (death, acute myocardial infarction, or revascularization). Median ST2 values were calculated for patients with and without each outcome. The AUCs were calculated for each outcome. In a post hoc analysis, patients with outlying increased ST2 values were examined to determine possible alternative causes for ST2 expression. Results There were 348 patients enrolled. The outcomes were acute myocardial infarction 17 patients (4.9%), acute coronary syndrome 39 (11.2%), and 30-day events 23 (6.6%). The AUCs for acute myocardial infarction, acute coronary syndrome, and 30-day events were 0.636, 0.630, and 0.579, respectively. ST2 did not predict acute myocardial infarction, acute coronary syndrome, or 30-day events. It was increased in a small number of patients with pulmonary disease, notably, pulmonary emboli, systemic infection or inflammation, and alcohol abuse. Conclusion ST2 was not of value in the evaluation of ED patients with potential acute coronary syndrome.